An-Najah Blogs :: Hikmat S. Hilal\\\'s Blog http://blogs.najah.edu/author/hikmat-hilal An-Najah Blogs :: Hikmat S. Hilal\\\'s Blog en-us Thu, 21 Nov 2019 18:26:36 IST Thu, 21 Nov 2019 18:26:36 IST webmaster@najah.edu webmaster@najah.edu Materials Research Prospects in Palestine. Case History: Semiconductor Research at Najahhttp://blogs.najah.edu/staff/hikmat-hilal/article/Materials-Research-Prospects-in-Palestine-Case-History-Semiconductor-Research-at-NajahPublished ArticlesMaterials Research Prospects in Palestine Case History: Semiconductor Research at Najah Presented by: Hikmat S Hilal College of Sciences An-Najah N University PO Box 7 Nablus West Bank Palestine Fax No 970-9-2944082 hikmathilal@yahoocom Participants: S Saleh I Sadeddin M Masoud W Atteereh S Shakhshir L Majjad A Hamouz N Zaatar and R Shubaitah R Ismael A Zyoud M Atatrih I Hamdan H Sabri M Al-Hasan An-Najah N University Palestine G Campet University of Bordeaux France N Jisrawi University of Birzeit Palestine J Turner NREL CO Abstract Palestine has limited natural resources Any future development should therefore be based on advanced technology Such ambitious outlook dictates that Palestine heavily invests in quality teaching and researching in such areas Materials research is one building block for building advanced technology The philosophy is simple: we need to develop a technology which intensively demands know-how rather than resources In short Palestine should develop a technology based on creativity and invention starting with advanced materials and their applications Advanced materials include a wide range of areas such as nanotechnology thin films nanodevices conductive polymers and others Applications of advanced materials span a number of areas such as: Energy storage devices super batteries supercapacitors fuel cells clean energy photovoltaics PV photoelectrochemistry PEC biotechnology drug delivery cancer treatment superconductivity superconducting magnets MRI super-trains and other applications LEDs electrochromics Semiconductors SC are a very important area of advanced materials Almost all contemporary technologies rely on SC systems such as p-n junctions transistors diodes PV PEC refregiration In this plenary we wish to give one specific example on where Palestinian scientists can target an area of advanced material research and can contribute effectively despite limited resources Semiconductor research activity has been established in the laboratories of An-Najah N University in the mid 1990s The activity started with modification of mono-crystalline n-Si and n-GaAs semiconductor surfaces for the purpose of controlling band edge positions This was for the purpose of tailoring band edge positions to catalyze water splitting into hydrogen and oxygen by solar light The objectives were successfully achieved by graduate students at ANU To simultaneously achieve stability and efficiency of the SC electrode other techniques were developed here Monocrystalline n-GaAs electrodes were enhanced in stability and efficiency using polymeric coatings with electroactroactive ions inside However the increasing cost of monocrystalline SC materials affected our objective Our efforts were then diverted to synthetic thin film SC electrodes Preparation of enhanced semiconducting materials in the forms of thin films and nano-scale particles have then been conducted for the purposes of light-to-electricity and water decontamination strategies Recently our students have been heavily engaged in preparing new classes of n-type semiconducting materials CdS and CdSe in the forms of thin films and nano-scale particles using Chemical Bath Deposition CBD and Electro-Chemical Deposition ECD techniques Thin CdS and CdSe films were deposited onto FTOglass systems and are currently being used for light-to-electricity conversion processes Modification of thin films with different techniques shows promising potential in enhancing efficiency and stability For the first time ANU students were able to stabilize CBD-based CdSe films in PEC processes Examples of SC research progress at ANU will be highlighted in this presentation Some technical results and discussions will be presented This is to give examples to young Palestinian scientists on what they can achieve should they work in advanced materials research directed towards solving societal problems It is also intended to attract the attention of decision makers to put materials RD as a high priority area in the near future plans Measurement of Neutral Gas Temperatures in Nitrogen-Corona Dischargeshttp://blogs.najah.edu/staff/hikmat-hilal/article/Measurement-of-Neutral-Gas-Temperatures-in-Nitrogen-Corona-DischargesPublished Articles Conditionally Accepted Ind J Physics Measurement of Neutral Gas Temperatures in Nitrogen-Corona Discharges Siham Khedim1 Ali Cheknane2 BoumedineBenyoucef1 and Hikmat S Hilal3 1Abou-beker Belkaid University- Tlemcen BP 119 13000 Tlemcen Algeria 2Laboratoire dEtude et Dveloppement des matriaux Dilectriques et Semiconducteurs Universit Amar Telidji de Laghouat Algrie 3Department of Chemistry An-Najah N University PO Box 7 Nablus West bank Palestine Corresponding author: E-mail: cheknanali@yahoocom ABSTRACT: The temperature of neutral gas of the nitrogen-corona discharge has been measured using a Mach-Zehnder interferometer The variation of the optical path in the interferometer has been measured together with the refraction index Density variations were also calculated Values of measured temperatures of the neutrals in the corona discharge were obtained under both positive and negative coronas Silica-supported CdS-sensitized TiO2 particles in photo-degradation of phenazopyridine: Assessment of efficiency, stability and recoveryhttp://blogs.najah.edu/staff/hikmat-hilal/article/Silica-supported-CdS-sensitized-TiO2-particles-in-photo-degradation-of-phenazopyridine-Assessment-of-efficiency-stability-and-recoveryPublished ArticlesIWAM2010 Ghazi Nour Ahed Zyoud and Hikmat S Hilal Silica-supported CdS-sensitized TiO2 particles in photo-degradation of phenazopyridine: Assessment of efficiency stability and recoveryPristine and supported ZnO-based catalysts for phenazopyridine degradation with direct solar lighthttp://blogs.najah.edu/staff/hikmat-hilal/article/Pristine-and-supported-ZnO-based-catalysts-for-phenazopyridine-degradation-with-direct-solar-light-1Published Articles Hikmat S Hilal Ghazi YM Al-Nour Ahed Zyoud Muath H Helal Iyad Saadeddin Abstract: In search for safe techniques to manage waste pharmaceutical compounds drained in water solar-driven degradation of phenazopyridine a model drug was investigated in aqueous media using different ZnObased catalyst systems Naked ZnO CdS-sensitized ZnO ZnOCdS and activated carbon-supported ZnO ACZnO have been studied Both naked ZnO and ACZnO were highly efficient in mineralizing phenazopyridine reaching complete removal in w 50 min with ACZnO having the higher edge The ZnOCdS system showed lower efficiency due to screening of light by CdS Moreover the tendency of CdS to leach out Cd 2 ions discouraged the use of CdS as sensitizer in this work In both ZnO and ACZnO systems the Water Purificationhttp://blogs.najah.edu/staff/hikmat-hilal/article/Water-PurificationPublished ArticlesA new research book under the title \Water Purification\ Nikolaj Gertsen and Linus Snderby Editors 2009 ISBN: 978-1-60741-599-2 has been published by Novascience Our research group at Najah has participated with three chapters in this book The chapters are: Chapter 5 Silica-supported CdS-sensitized TiO2 Particles in Photo-Driven Water Purification: Assessment of Efficiency Stability and Recovery Future Perspectives p 203 Ahed H Zyoud and Hikmat S Hilal Chapter 6 Photo-degradation of Methyl Orange with Direct Solar Light Using ZnO and Activated Carbon-supported ZnO p 227 Hikmat S Hilal Ghazi Y M Nour and Ahed Zyoud Chapter 8 Why Vapor Pressure of a Volatile Liquid Decreases by Addition of Solutes: A New Qualitative Model p 275 Hikmat S Hilal and Ali Cheknane CdS-sensitized TiO2 in phenazopyridine photo-degradation: Catalyst efficiency, stability and feasibility assessmenthttp://blogs.najah.edu/staff/hikmat-hilal/article/Feasibility-of-CdS-sensitized-TiO2-in-large-scale-medical-compound-degradation-with-solar-lightPublished Articles Journal of Hazardous Materials 173 2010 318325 Ahed H Zyoud Nidal Zaatar and Cheknane Ali Iyad Saadeddin DaeHoon park Guy CampetHikmat S Hilal Ahed H Zyoud Nidal Zaatar and Cheknane Ali Iyad Saadeddin DaeHoon park Guy CampetHikmat S Hilal Abstract: Feasibility of using CdS-sensitized TiO2 catalyst systems was investigated in visible-light driven degradation of a medically active contaminant phenazopyridine 1 in water The TiO2CdS systems showed high activity compared to un-sensitized TiO2 counterpart The reaction kinetics were consistent with photodegradation processes encountered with other contaminants The tendency of the sensitizer CdS to leach out hazardous Cd2 ions was observed under photo-degradation conditions To prevent leaching different techniques were attempted such as annealing the TiO2CdS system and supporting it onto solid sand supports Unfortunately complete prevention of Cd2 ion leaching out was not possible by these methods under different experimental conditions Therefore unless complete prevention of such leaching out process is attainable the use of CdS and other hazardous synthetic sensitizers should be avoided Ahed H Zyoud Nidal Zaatar and Cheknane Ali Iyad Saadeddin DaeHoon park Guy CampetHikmat S Hilal SILICA-SUPPORTED CdS-SENSITIZED TiO2 PARTICLES IN PHOTO-DRIVEN WATER PURIFICATION: ASSESSMENT OF EFFICIENCY, STABILITY AND RECOVERY FUTURE PERSPECTIVEShttp://blogs.najah.edu/staff/hikmat-hilal/article/Silica-supported-CdS-sensitized-TiO2-particles-in-photo-driven-water-purificationPublished Articles Ahed Zyoud and Hikmat S Hilal Department of Chemistry Najah N University P O Box 7 Nablus West Bank Palestine E-mail: hikmathilal@yahoocom Fax: 970-9-2387982 Abstract: Surfaces of Rutile TiO2 particles have been modified with CdS particles The TiO2CdS system has been used as catalyst in water purification by photo-degradation of organic contaminants such as methyl orange a commonly encountered contaminant dye and Phenazopyridine a commonly encountered medically active drug Both UV and Visible ranges have been investigated CdS sensitization of TiO2 to visible region has been observed as the TiO2CdS system showed higher catalytic efficiency than the naked TiO2 system in the visible region While showing relatively higher stability to photo-degradation conditions at higher pH values the TiO2CdS system was unstable under neutral and acidic conditions Significant amounts of CdS degraded into hazardous aqueous Cd2 ions while working at pH 7 or lower This imposes limitations on future usage of CdS-sensitized TiO2 photo-catalytic systems in water purification processes In an effort to solve out the leaching difficulties and to make catalyst recovery easier the TiO2CdS system has been supported onto insoluble silica particles giving SilicaTiO2CdS systems for the first time The silicaTiO2CdS system showed lower efficiency than TiO2 and TiO2CdS systems in both UV and Visible regions However silica support has an added application value to the catalytic system by making its recovery much easier after reaction completion Unfortunately the difficulty of the Cd2 ion leaching out has not been solved out for silicaTiO2CdS system Despite the numerous literature reports on using CdS as sensitizer for TiO2 in degradation studies its tendency to leach out puts a limitation on its future usage Replacement with other more safe dyes should therefore be considered Effects of catalyst concentration catalyst recovery contaminant concentration temperature and pH on catalyst efficiency have also been studied WHY VAPOR PRESSURE OF A VOLATILE LIQUID DECREASES BY ADDITION OF SOLUTES: A NEW QUALITATIVE MODELhttp://blogs.najah.edu/staff/hikmat-hilal/article/WHY-VAPOR-PRESSURE-OF-A-VOLATILE-LIQUID-DECREASES-BY-ADDITION-OF-SOLUTESPublished Articles Hikmat S Hila1 and Ali Cheknane2 1 Department of Chemistry An-Najah N University PO Box 7 Nablus West Bank Palestine Fax No: 970-9-2387982 E-mail: hikmathilal@yahoocom 2 Laboratoire d Etudes st Developpement de Materiaux Semiconducteurs et Dielectriques Universite Amar Telidji de Laghouat route de Ghardaia BP 37G Laghouat 03000 Algerie Corresponding author ABSTRACT While explaining vapor pressure lowering in solutions many general scholars mistakenly depend on rate of evaporation lowering or on relative values of attraction forces between solvent and solute molecules This is in spite of the correct explanations based on thermodynamics as presented in physical chemistry references Unfortunately there seems to be no qualitative model available so far to explain vapor pressure lowering The misconception is escalating and an end needs to be made A qualitative understandable model to explain vapor pressure lowering at least in solutions of nonvolatile solutes in volatile solvents is needed For this purpose we propose here a new qualitative model to explain vapor pressure lowering in such solutions The new model is based on purely old thermodynamic concepts Photo-degradation of methyl orange with direct solar light using ZnO and activated carbon-supported ZnOhttp://blogs.najah.edu/staff/hikmat-hilal/article/Photo-degradation-of-methyl-orange-with-direct-solar-light-using-ZnO-and-activated-carbon-supported-ZnOPublished ArticlesHikmat S Hilal Ghazi Y M Nour and Ahed Zyoud Department of Chemistry An-Najah N University PO Box 7 Nablus West bank Palestine Fax: 00-970-9-2387982 E-mail: hikmathilal@yahoocom ABSTRACT ZnO is a wide band gap 32 eV semiconductor with limited photo-catalytic applications to shorter wavelengths only However it is suitable to use in solar light photo-degradation of different contaminants due to a number of reasons taking into account that the reaching-in solar radiation contains only a tail in the near UV region The high absorptivity of ZnO makes it efficient photo-catalyst under direct solar light Moreover it is relatively safe abundant and non costly In this chapter ZnO has been investigated as a potential catalyst for photo-degradation of methyl orange a known dye in aqueous solutions with direct natural solar light under different conditions The major aim was to assess the efficiency and stability of ZnO under photo-electrochemical PEC conditions and to suggest techniques to enhance such features This will shed light on the future applicability of ZnO as a candidate for economic and friendly processes in water purification Recovery of ZnO particles after reaction completion has been facilitated by supporting ZnO onto activated carbon to yield ACZnO system The ACZnO was used as catalyst for contaminant photo-degradation in water solutions under direct solar light Both catalytic systems naked ZnO and ACZnO were highly efficient in degrading both contaminants reaching complete removal in reasonable times The latter system showed higher efficiency In both systems the reaction goes faster with higher catalyst loading until a maximum efficiency is reached at a certain concentration after which the catalyst concentration did not show a systematic effect In both catalytic systems the rate of degradation reaction increases with higher contaminant concentrations until a certain limit is used The contaminant degradation reaction was studied using both catalysts at different pH values The pH value 80 gave the highest catalyst efficiency The tendency of naked ZnO to degrade into soluble zinc ions under photo-degradation experiments was studied under different pH values Catalyst recovery and reuse experiments were conducted on both systems The catalytic activity of the recovered systems was only slightly lower than the fresh system in each case The fourth time recovered catalysts showed up to 50 efficiency loss in each case presumably due to ZnO degradation and leaching out However fresh and recovered catalyst systems caused complete degradation of contaminants after enough time Temperature showed a slight effect on rate of reaction with immeasurably small activation energy value Details of effects of other parameters on reaction rate and catalyst efficiency are described Using CdS as sensitizing dye failed to enhance ZnO efficiency under direct solar light The screening effect and tendency of CdS to leach out limit its use as ZnO sensitizer Tendency of ZnO to leach out zinc ions into solution is discussed The naked ZnO and ACZnO systems are promising photo-catalysts in future water purification technologies by direct solar light Accepted as a chapter in a book Water Purification Novascience 2008 PHOTO-DEGRADATION OF ORGANIC CONTAMINANTS BYhttp://blogs.najah.edu/staff/hikmat-hilal/article/PHOTO-DEGRADATION-OF-ORGANIC-CONTAMINANTS-BYPublished ArticlesPHOTO-DEGRADATION OF ORGANIC CONTAMINANTS BY DYES-SENSITIZED NANOPARTICALES OF TiO2 SUPPORTED ONTO INSOLUBLE SUPPORTS Ahed Zyoud Hikmat S Hilal Semi-conducting nano-materials are being used as catalysts for photo-degradation of water contaminants In TiO2 photo-catalytic activity process electronhole pairs that are generated by the band-gap excitation carry out in situ degradation of toxic pollutants The holes oxidize toxic organic compounds and the electrons reduce toxic metal ions to metals or oxygen to oxide Instead of decomposed a toxic CdS dye a safe sensitize natural dyes were used Both prepared TiO2Natural dye systems show an efficient photodegradation result on both mentioned contaminants model The prepared natural dye sensitized catalyst were supported on A Also Kinetics effect of temperature effect of pH and farther studies were applied on the prepared catalyst TiO2 nanparticles were sensitized by dyes in order to activate the photo-degradation processes by the visible light Thin films of TiO2 nanoparticales was supported onto insoluble surfaces such as sand and AC from TiCl3 The resulting TiO2 nanoparticales are being modified with CdS a short band-gab semiconductor for sensitization purposes Such model is explained in Scheme 1 producing [SandTiO2CdS] system SandTiO2CdS system was being applied in degradation of methyl orange and Phenazopyridine Results of our photo-degradation study Kinetics effect of temperature effect of pH Completely decomposition of CdS was found through treatment process ASSESSMENT OF CdS AS SENSITIZER FOR TiO2 and ZnO IN WATER PURIFICATION WITH SOLAR LIGHThttp://blogs.najah.edu/staff/hikmat-hilal/article/ASSESSMENT-OF-CdS-AS-SENSITIZER-FOR-TiO2-and-ZnO-IN-WATER-PURIFICATION-WITH-SOLAR-LIGHTPublished Articles Hikmat S Hilal Ahed Zyoud and Ghazi Nour Department of Chemistry An-Najah N University Nablus West Bank Palestine Fax: 970-9-2387982 E-mail: hikmathilal@yahoocom Key Words: Solar light water purification TiO2 ZnO TiO2 and ZnO nano-particles are known to behave as catalysts for photo-degradation of water contaminants [1-7] Once excited the electrons jump from the valence band to the conduction band of the particles This process creates the so-called electron-hole pairs The electrons may then reduce different species such as aqueous oxygen On the other hand the holes oxidize organic contaminant molecules Having a relatively high band gap ~32 eV and a valence-band edge with very highly positive potential TiO2 and ZnO are expected to have very strong oxidizing power towards almost all organic contaminants Such features make them good candidates for water purification using the cost-free solar light Moreover they are non-hazardous low cost materials with a very high thermal and chemical stability However the high band gaps limit their use in solar energy since they demand UV light for excitation Solar light that reaches our earth is mostly in the visible and IR region with very little UV Therefore their applications are limited to the UV region In order to use it in the visible region researchers modified TiO2 particles with dyes in a so-called sensitization strategy [8-15] In sensitization the dye molecules are excited with visible light Electron-hole pairs are thus created The hole would then oxidize contaminants and electrons immigrate toward the TiO2 valence band Such model is explained in Scheme 1 In our search for efficient and economic catalytic systems for water purification processes we have modified the surfaces of TiO2 nano-particles with different types of dyes Synthetic 246-triphenylpyrilium hydrogen sulfate-TPPHS- metalloporphyrins CdS and CdSe and natural Henna Pecan and others dyes have been attached to TiO2 surfaces Despite the fat that many natural dyes lack high stability they are potentially valuable due to their non-toxic nature The TiO2dye systems have been investigated as catalysts for photo-degradation of different organic contaminants in water such as pesticides phenols oxalic acid medically active ingredients and others Both UV and Visible regions have been studied In the UV region the dyes affected the rates of degradation by behaving as charge transfer mediators between the semiconductor solid surface and the contaminant molecules In the visible region the dyes behaved as sensitizers for the TiO2 semiconductor [16] Despite this the CdS leached out hazardous Cd2 ions into solution We tried to prevent such leaching by supporting the TiO2CdS onto solid silica but the problems were not solved out This puts limits on the potential use of CdS as sensitizer for water purification Contrary to TiO2 the ZnO particles did not function with dyes Their efficiency was lowered by the dye due to screening effects We have seen that ZnO works efficiently in direct solar light by the UV tail available This is due to the high UV absortivity of ZnO particles The TiO2Dye and ZnO systems were then supported onto surfaces of insoluble supports such as activated carbon clay glass and sand [16] In the supportTiO2Dye systems and supportZnO the support showed further enhancement in catalytic degradation of contaminants in the UV and visible regions The support surface presumably adsorbs contaminant molecules and brings them into close proximity with the catalytically active sites thus enhances the efficiency Moreover the hydrophobic nature of the solid surfaces makes the supportcatalyst easier to separate and isolate after use The supportedcatalyst systems showed promising recovery-reuse features for more than three times with not much loss of efficiency The results observed in these laboratories together with relevant discussions and models regarding sensitization and charge transfer re-mediations will be presented in this plenary Environmental impact technical difficulties economic considerations and future perspectives will also be discussed Scheme 1: Schematic sensitization model Acknowledgement: The work described here has been completed in collaboration with many colleagues References: 1 Davide Vione Claudio Minero Valter Maurino M Eugenia Carlotti Appl Catal B: Environmen 58 79-88 2005 2 A Ajmera S Pangarka and Beenakers Chem Eng Technol 25 180-186 2002; R Single M Ashokkkurnar and F Grieser Res Chem Intermed 30 723- 734 2004 3 V Bresova M Ceppan E Bradstetova M Breza and L Lapcik J Pholoiol 59 385-391 1991 4 R Matthews Wat Res 24 653-660 1990 5 K Mehrotra G Yablonsky and A Ray Chemosphere 60 1427 1436 2005 6 D Ossi A Mokrini E Chamarro and S Esplugas Environmen Technol 19 955-960 1998 7 C Karapire C Zafer and S li Synth Met 145 2004 51-60 8 Md K Nazeeruddin S M Zakeeruddin J -J Lagref P Liska P Comte C Barolo G Viscardi K Schenk and M Graetzel Coord Chem Rev 248 1317-1328 2004; B ORegan and M Grtzel Nature 353 737-740 1991 9 M Nazeeruddin A Kay I Rodicio R Humphry-Baker E Mller P Liska N Vlachopoulos and M Grtzel J Am Chem Soc 115 6382-6390 1993 10 G Granados O C A Pez M F Martnez O and E A Pez-Mozo Catal Today 107108 589 2005 11 D Chatterjee Sh Dasgupta and N N Rao Solar Energy Materials and Solar Cells 90 1013-1020 2005 12 T L Villarreal P Bogdanoff P Salvador N Alonso-Vante Solar Energy Materials and Solar Cells 83 347362 2004 13 M R Iesce M L G F Cermola S Montella L di Gioa and C Stasio Chemosphere 51 163 2003 14 -CH Ao and SC Lee J Photochem Photobiol A: Chem 161 131-140 2004 15 O Carp C L Huisman and A Reller Prog Solid State Chem 32 33 2004 16 Hikmat S Hilal Lamees Majjad Nidal Zaatar and Amer El-Hamouz 9 9-15 2007 17 Ahed H Zyoud and Hikmat S Hilal Silica-supported CdS-sensitized TiO2 particles in photo-driven water purification: Assessment of efficiency stability and recovery future perspectives Finally accepted as a chapter in a book Water Purification Novascience 2008; and Hikmat S Hilal Ghazi Y M Nour and Ahed Zyoud Photo-degradation of methyl orange with direct solar light using ZnO and activated carbon-supported ZnO Finally accepted as a chapter in a book Water Purification Novascience 2008 Effect of cooling rate of pre-annealed CdS thin film electrodes prepared by chemical bath deposition: Enhancement of photoelectrochemical characteristicshttp://blogs.najah.edu/staff/hikmat-hilal/article/Effect-of-cooling-rate-of-pre-annealed-CdS-thin-film-electrodes-prepared-byPublished Articles Hikmat S Hilal1 Rania M A Ismail2 and Amer El-Hamouz3 Ahed Zyoud1 Iyad Saadeddin4 1Department of Chemistry 2Clean Energy and Conservation Energy Study Program 3Department of Chemical Engineering 4Department of Physics An-Najah N University PO Box 7 Nablus West Bank Palestine Fax: 00970-9-2387982 Corresponding author: hikmathilal@yahoocom Abstract Thin films of CdS deposited by Chemical Bath Deposition CBD onto films of fluorine-doped tin oxideglass glassFTO substrates were prepared and investigated for photo-electrochemical PEC conversion of light into electricity Knowing the hazardous nature of CdS the focal theme of this work was to modify the electrodes by simple economic ways to maximize their conversion efficiency and minimize their degradation under PEC conditions This was to avoid leaching out of hazardous Cd2 ions Different parameters have been investigated for this purpose Multi-deposition preparation redox couple and electrode etching affected electrode PEC characteristics Consistent with earlier literature annealing the electrode enhanced its conversion efficiency and stability On the other hand effect of cooling rate of pre-annealed CdS electrodes prepared by CBD on their PEC characteristics has been investigated here for the first time Controlling the cooling rate was one major factor that affected CdS surface morphology conversion efficiency and stability under PEC conditions The major recommendation coming out here is that PEC characteristics of CdS thin film electrodes can be significantly enhanced by pre-annealing the electrode at ~250oC followed by its slow cooling Electrochimica ActaArticle in Press Accepted Manuscript 2009 Crystalline Silicon Solar Cell on Ceramic Substrates Under Solar Concentrationhttp://blogs.najah.edu/staff/hikmat-hilal/article/Crystalline-Silicon-Solar-Cell-on-Ceramic-Substrates-Under-Solar-ConcentrationPublished ArticlesA Cheknane A Chaker B Benyoucef H S Hilal 1Laboratoire dEtude et Dveloppement des Matriaux Semiconducteurs et Dilectriques Universit Amar Telidji de Laghouat BP 37 G route de Ghardaa Laghouat Algrie 2Laboratoire de Physique Energtique Universit de Mentouri de Constantine Algrie 3Unit de Recherche Matriaux et Energies Renouvelables Universit Abou Bakar Belkaid de Tlemcen Algrie4An-Najah N University PO Box 7 Nablus West Bank Palestine Abstract - SiC-based and Al2O3-based Si solar cells together with a single p-n Si homo-junction solar cell have been investigated Open-circuit voltage short circuit current and cell efficiency for each solar cell have been measured under different solar concentrations The parameters for all cells were improved with higher concentration levels The open circuit voltage reached a maximum value under 500 sun concentration for each cell Efficiency values of 314 275 and 20 for the SiC-based cell Al2O3-based cell and the homo-junction cell respectively have been obtained when appropriate cooling systems were used Such difference is presumably due to the more efficient cooling mechanism of the substrates being more efficient for SiC This characteristic together with cost considerations and mechanical properties makes the SiC substrate a good candidate to support Si thin film solar cells International Review of PhysicsFeb 1st 2008 Copyright 2008 Praise Worthy Prize Srl - All rights reserved http:wwwpraiseworthyprizecomIREPHY_vol_2_n_1htmlCrystalline20Silicon20Solar20Cell20on20Ceramic20Substrates20Under20Solar20Concentration An equivalent circuit approach to organic solar cell modellinghttp://blogs.najah.edu/staff/hikmat-hilal/article/AN-EQUIVALENT-CIRCUIT-APPROACH-TO-ORGANIC-SOLAR-CELL-MODELINGPublished ArticlesMicroelectronics Journal 39 2008 11731180 Ali CHEKNANE1 Hikmat S HILAL2 Fayal Djeffal3 Boumedine BENYOUCEF4 and Jean-Pierre CHARLES5 1Laboratoire dEtude et Dveloppement des Matriaux Semiconducteurs et Dilectriques BP Universit Amar Telidji 37G route de Ghardaa Laghouat Algrie Email: cheknanali@yahoocom 2An-Najah N University PO Box 7 Nablus West Bank Palestine 3LEA Department of Electronics University of Batna Algeria 4Unit de Recherche Matriaux et Energies Renouvelables Universit Abou Bakar Belkaid de Tlemcen Algrie 5LMOPS-CNRS UMR 7132 SUPELEC 2 rue Edouard Belin 57070 Metz France Abstract: In this paper we present a simulation study for a newly prepared organic solar cell based on a composite of poly 2-methoxy-5-2-ethylhexyloxy-1 4-phenylenevinylene MEH-PPV with [6 6]-phenyl C60 butyric acid methyl ester PCBM Photo-current density vs voltage J-V characteristics for the cell which were experimentally studied earlier have been revisited here The results indicated that the conduction mechanism in the organic solar cell is strongly influenced by the excitonic diffusion Sound correlation between theoretical and experimental photo-current density vs voltage J-V plots has been achieved Moreover the simulation clearly demonstrates that the performance of the tested device can be described with sound accuracy by a two diode-equivalent model DYE-EFFECT IN TiO2 CATALYZED CONTAMINANT PHOTODEGRADATION: SENSITIZATION VS. CHARGE-TRANSFER FORMALISMhttp://blogs.najah.edu/staff/hikmat-hilal/article/DYE-EFFECT-IN-TiO2-CATALYZED-CONTAMINANT-PHOTODEGRADATIONPublished Articles H S Hilal1 L Z Majjad1 N Zaatar1 and A El-Hamouz2 1Department of Chemistry2Department of Chemical Engineering An-Najah N University PO Box 7 Nablus Palestine Solid State Sciences 920079-15 Corresponding author: Fax: -970-9-287 982 E-mail: hikmathilal@yahoocom Abstract: Anatase TiO2 surfaces have been treated with 246-triphenylpyrilium hydrogen sulfate TPPHS dye to yield the modified TiO2TPPHS surface The modified TiO2TPPHS surface was then supported onto activated carbon AC surfaces to yield a new class of catalytic system ACTiO2TPPHS The catalytic activities of naked TiO2 TPPHS solution TiO2TPPHS and ACTiO2TPPHS systems were examined in photo-degradation of phenol and benzoic acid in water using both UV and visible regions All studied systems showed low catalytic activity when used in the visible In UV the ACTiO2TPPHS showed highest activity whereas the naked TiO2 and TPPHS solution were the least active systems The dye role in enhancing activity of modified surfaces in UV degradation of contaminants is understandable by a charge transfer catalytic effect rather than a sensitizing effect AC role is explainable by its ability to adsorb contaminant molecules and bringing them closer to catalytic sites Single-Doped and Co-Doped SnO2 Transparent Thin Film Electrodeshttp://blogs.najah.edu/staff/hikmat-hilal/article/Single-Doped-and-Co-Doped-SnO2-Transparent-Thin-Film-ElectrodesPublished Articles SnO2 doped thin films for optoelectronic applications have been prepared by sputtering from two different targets: ATO antimony doped tin oxide and ATZO antimony and Zn doped tin oxide These films have been characterized by electron probe x-ray microanalysis x-ray photospectroscopy for the composition x-ray diffraction scanning electron microscopy and atomic force microscopy for the morphology and the microstructure The optical properties have been studied by transparency and reflectivity measurements In the case of ATO thin film that have a metallic behavior some calculations based on Drude model have been carried out to determine the number of charge carrier and their optical mobility The electrical properties of the thin films have been evaluated from resistivity four probe set-up and hall measurements Best optoelectronic performance has been obtained for ATO thin film doped with 15 of Sb Even if the conductivity is lower for ATZO films the latter can be prepared with a higher deposition rate and it allows having a conductivity modulation Solid olive waste in environmental cleanup: Oil recovery and carbon production for water purificationhttp://blogs.najah.edu/staff/hikmat-hilal/article/Solid-olive-waste-in-environmental-cleanupPublished ArticlesJournal of Environmental Management 84 2007 8392 Amer El-Hamouza Hikmat S Hilalb Nashaat Nassara Zahi Mardawia aDepartment of Chemical Engineering An-Najah National University PO Box 7 Nablus Palestine bDepartment of Chemistry An-Najah National University PO Box 7 Nablus Palestine Received 3 September 2005; received in revised form 12 May 2006; accepted 17 May 2006 Available online 10 July 2006 Abstract A potentially-economic three-fold strategy to use solid olive wastes in water purification is presented Firstly oil remaining in solid waste higher than 5 of waste was recovered by the Soxhlet extraction technique which can be useful for the soap industry Secondly the remaining solid was processed to yield relatively high-surface area active carbon AC Thirdly the resulting carbon was employed to reversibly adsorb chromate ions from water aiming to establish a water purification process with reusable AC The technique used here enabled oil recovery together with the production of a clean solid suitable for making AC This process also has the advantage of low production costMODELLING AND SIMULATION OF InGaP SOLAR CELLS UNDER SOLAR CONCENTRATION: SERIES RESISTANCE MEASUREMENT AND PREDICTIONhttp://blogs.najah.edu/staff/hikmat-hilal/article/MODELLING-AND-SIMULATION-OF-InGaP-SOLAR-CELLS-UNDER-SOLAR-CONCENTRATIONPublished ArticlesA Cheknane1 H S Hilal2 J P-Charles3 B Benyoucef1 and G Campet4 1Unit de Recherche des Matriaux et Energies Renouvelables Universit Abou Bakr Belkaid Tlemcen Algrie 2An-Najah N University PO Box 7 Nablus West Bank Palestine 3MOPS SUPELEC 2 rue Edouard Belin 57070 Metz FRANCE 4CNRS Universite Bordeaux I Chteau Brivazac Ave du Dr A Schweitzer 33600 Pessac France Corresponding author: Fax: 970-9-2944082 E-mail: hikmathilal@yahoocom Abstract One of the important parameters that commonly affect solar cell performances is the series resistance Such effect becomes more pronounced when working under higher illumination intensities due to higher generated photocurrents Therefore it is necessary to predict series resistance effects under such conditions To know more about the series resistance effect and its interpretation InGaP based solar cell performances were investigated using high solar concentration levels 7336 X 20119 X To facilitate the prediction of series resistance effect as a function of insolation level a computerised analytical model using neural network is presented Solid State Sciences Volume 8 Issue 5 May 2006 Pages 556-559 Controlling charge-transfer processes at semiconductor/liquid junctionshttp://blogs.najah.edu/staff/hikmat-hilal/article/CONTROLLING-CHARGE-TRANSFER-PROCESSES-AT-SEMICONDUCTORPublished Articles Electrochimica Acta 51 2006 64876497 H S Hilal and J A Turner Abstract The interfacial kinetics of charge transfer at n-GaAsliquid junctions were controlled by anchoring positively charged species such as tetra- 4-pyridylporphyrinatomanganeseIII with the semiconductor surface Unlike earlier adsorption techniques the charges have been chemically anchored to the semiconductor surface in this work via a ligand The number of charges per site attached molecule ranged from 1 to 5 The positive charges shifted the band-edges towards more positive potential values The degree of shift increased with surface charge density In the dark the flat band potential measured by MottSchottky technique and the onset potential were shifted by up to 300mV depending on surface charge density Relatively less of a shift was observed during illumination of the system Other surface characteristics such as conversion efficiency and photoluminescence intensity have been enhanced The basis for these shifts and their implications with respect to control of interfacial processes are discussed Size fractionation and characterization of natural colloids by flow-field flow fractionation coupled to multi-angle laser light scatteringhttp://blogs.najah.edu/staff/hikmat-hilal/article/Size-fractionation-and-characterization-of-natural-colloids-by-flow-field-flow-fractionation-coupled-to-multi-angle-laser-light-scatteringPublished ArticlesJournal of Chromatography A 11042006272-281 M Baalousha FVD Kammer M Motelica-Heino H S Hilal and P Le Coustumer Abstract Flow-field flow fractionation FlFFF coupled to multi-angle laser light scattering MALLS was evaluated for size and shape determination of standard spherical and arbitrarily shaped natural colloids Different fitting methods for light scattering data retrieved from MALLS were evaluated to determine the particle size of spherical standards and natural colloids In addition FlFFF was optimized for best fractionation in connection to MALLS minimal colloids-membrane interaction and minimal sample losses FlFFF calibrated with standard particles was used to determine hydrodynamic diameter or radius Dh or Rh of the fractionated colloids whereas the MALLS was used to determine root mean square radius of gyration Rg for fractionated colloids Combining both results by calculating the RgRh ratio allows an estimation of colloid deviation from the shape of homogeneous sphere Accordingly this study demonstrates that FlFFFMALLS is a valuable technique for characterizing heterogeneous and arbitrarily shaped natural colloidal particles in terms of size and shape To check the usefulness of FlFFFMALLS in natural colloid studies the technique was used to investigate the sedimentation behavior of extracted soil colloidal particles Results illustrate that in a silty till sample carbonates function as cement between the colloidal particles and consequently change their sedimentation behavior On the other hand carbonate dissolution generates a more homogeneous colloidal sample 2005 Published by Elsevier BV Synthesis of a new series of heterocyclic scaffolds for medicinal purposeshttp://blogs.najah.edu/staff/hikmat-hilal/article/Synthesis-of-a-new-series-of-heterocyclic-scaffolds-for-medicinal-purposesPublished Articles European Journal of Medicinal Chemistry 41 2006 1017 1024 HS Hilal a MS Ali-Shtayeh a R Arafat a T Al-Tel a W Voelter b A Barakat College of Sciences An-Najah N University PO Box 7 Nablus Palestine b Abteilung fr Physikalische Biochemie des Physiologisch-Chemischen Instituts der Universitt Tbingen Hoppe-Seyler Strae 4 72076 Tbingen Germany Abstract A new series of substituted 8-fluro-4 H-pyrimido[21-b] [13]benzothiazole-4-ones substituted 7-methyl-4H-isoxazolo[23-a]pyrimidin-4- ones and substituted 2-methyl-5678-tetrahydro-9 H-isoxazolo[23-a]pyridopyrimidin-9-ones compounds IVII have been prepared via condensation of -keto esters with 2-aminopyridine derivatives in the presence of polyphosphoric acid The same technique has also been used to prepare diazepine compounds VIIIX by condensation of a -keto ester with 2-aminopyridine derivatives Details of synthetic procedures are shown The new compounds have been characterized by elemental analysis GC MS FT-IR and NMR spectrometry Antibacterial antifungal and anticancer cytotoxic activities for three of these compounds have been investigated and are presented 2006 Elsevier SAS All rights reserved Conference//Utilization of Olive Solid Waste (Jift) in Removing Chromium from Synthetic Wastewaterhttp://blogs.najah.edu/staff/hikmat-hilal/article/ConferenceUtilization-of-Olive-Solid-Waste-Jift-in-Removing-Chromium-from-Synthetic-WastewaterPublished Articles Abstract Preview Z2CCIH 2006 56th Canadian Chemical Engineering Conference Utilization of Olive Solid Waste Jift in Removing Chromium from Synthetic Wastewater N N Nassar Z Mardawi A El-Hamouz H Hilal Department of Chemical and Petroleum Engineering University of Calgary Calgary AB Canada Solid waste from olive oil production is a significant problem in Mediterranean countries for example Palestine produces annually from12000 to 14000 tons In this study Jift a burned solid olive waste which is known to be environmentally hazardous; was used in environmental protection This study investigated the applicability of using Jift were selected and tested for their chromium adsorption capacity from aqueous solutions The adsorption equilibrium results showed that Jift with particles size 425 m diameter achieved the highest adsorption capacity The adsorption capacity was attributed to the surface characteristic as well as the surface area of Jift The adsorption isotherms were represented by Langmuir andor Freundlich isotherms The removal of chromium by Jift adsorption was successfully achieved Moreover utilization of Jift was proposed for the preparation and enhancement activated carbon The cost estimation of this full utilization of the Jift in extracting olive oil wastewater treatment and producing safe fuel was performed and found to yield an IRR value of 12 It is evident from the experimental results and feasibility studies that the use of Jift chromium removal seems to be technically feasible environmentally friendly and economically attractive for the treatment of Cr-contaminated wastewaterfor adsorbing chromium from wastewater Four different particle sizes of Jift Low Temperature Sintering and Dielectric Properties of (Ba,Ca)(Ti,Li)(O,F)3 Ceramics with High Permittivityhttp://blogs.najah.edu/staff/hikmat-hilal/article/Low-Temperature-Sintering-and-Dielectric-Properties-of-Published ArticlesSolid State Sciences 8 2006 922926 Laldja TABIBENZIADA H S HILAL and Rgnault VON DER MHLL Abstract Cold-pressed pellets were prepared from a powder mixture of BaTiO 3 with 5 mol of CaF2 LiF The pellets were then air-fired at different temperatures 800 930 1000 or 1100 ◦C for different times 2 4 or 8 h Dielectric measurements were conducted at temperatures in the range 100450 K with a wide frequency range 100 Hz40 MHz Permittivity r showed a diffuse ferroelectricparaelectric phase transition at lower temperatures 263 K TC 368 K where TC is the Curie temperature In agreement with a non-relaxor ferroelectric behavior the ferroelectric Curie temperature was frequency-independent Dielectric dispersion was significant beyond 10 MHz Ceramics sintered between 930 and 1100 ◦C are promising candidates for future fabrication of class II capacitors 2006 Elsevier SAS All rights reserved Simultaneous doping of Zn and Sb in SnO2 ceramics: Enhancement of electrical conductivityhttp://blogs.najah.edu/staff/hikmat-hilal/article/Simultaneous-doping-of-Zn-and-Sb-in-SnO2-ceramicsPublished Articles Solid State Sciences 8 2006 713 I Saadeddin HS Hilal b B Pecquenard a J Marcus c A Mansouri d C Labrugerea MA Subramanian e G Campet a Institut de Chimie de la Matire Condense de Bordeaux CNRS-UPR9048 Universit Bordeaux I 87 Avenue de Dr Albert Schweitzer 33608 Pessac France b Department of Chemistry An-Najah National University PO Box 7 Nablus Palestine c Laboratoire dEtudes des Proprits Electroniques des Solides CNRS-UPR11 25 Avenue des Martyrs 38000 Grenoble France d Institut Europen des Membranes IEM Universit Montpellier II Place Eugne Bataillon 34095 Montpellier France e DuPont Central Research Development Experimental Station Wilmington DE 19880-0328 USA Abstract SnO 2-based ceramics doped with Sb andor Zn have been prepared by solid state reaction at 1300 ◦C The effect of dopants on electronic properties and sintering behavior has been studied While undoped SnO 2 pellets displayed very low electrical conductivities and lower densities the Sb-doped ceramics showed higher electrical conductivity with almost no densification and a significant antimony loss On the contrary a high densification and low conductivity are obtained for Zn-doped ceramics Therefore it is worthwhile to investigate SnO 2 ceramics co-doped with Sb and Zn SnO 2:Sb:Zn to combine the advantages of both dopants X-ray photoelectron spectroscopy XPS analysis confirmed that Sb5 is mainly substituted at the Sn 4 site for Sb-doped ceramics and is in agreement with Hall-measurements In the case of SnO2 samples co-doped with Sb and Zn XPS and Hall data confirmed the presence of both Sb 5 and Sb3 The SnO2:Sb:Zn system exhibited enhanced electrical conductivity and high densities In addition the presence of Zn prevented the Sb evaporation during sintering THERMODYNAMIC CORRELATIONS AND BAND GAP CALCULATIONS IN METAL OXIDEShttp://blogs.najah.edu/staff/hikmat-hilal/article/THERMODYNAMIC-CORRELATIONS-AND-BAND-GAP-CALCULATIONS-IN-METAL-OXIDESPublished ArticlesProgress in Solid State Chemistry 32 20045 207-217 J Portier H S HILAL I SAADEDDIN SJ HWANG and G Campet Abstract Thermodynamic parameters and energy-band gap of a given metal oxide are suitable measures of its stability For this reason direct correlations between energy-band gap or chemical hardness and thermodynamic parameters eg standard enthalpy of formation have been constructed for different metal oxides Furthermore a simple relationship to calculate values of energy-band gaps for metal oxides from values of their enthalpies of formation is presented here When tested an appreciable number of metal oxides from s- p- and d-blocks well obeyed the relationship while a number of metal oxides deviated A qualitative theoretical account for such different behaviors is presented here 2005 Elsevier Ltd All rights reserved Organic-Inorganic Poly(3,4-ethylenedioxythiophene)/V2O5 and Polypyrrole/g-Fe2O3 Nano-Hybrids as Lithium Insertion Electrodes”, http://blogs.najah.edu/staff/hikmat-hilal/article/Organic-Inorganic-PolyPublished Articlesinvited chapter in the book Progress in Electrochemistry Research Electrochemical Studies of Batteries 2005115-146 Novascience PublISBN: 1-59454-329-1 AV Murugan M Quintin CW Kwon O Devos MH Delville H S Hilal and G Campet Nova Science Publishers Inc Hauppauge NY Proof finally accepted June 2005 Abstract To develop new electrode materials for Li batteries two different approaches are presented namely: i lamellar organic-inorganic hybrid materials synthesized by intercalation of monomeric units of a conductive polymer intercalation approach; and ii 3-dimensional transition-metal oxide nanoparticles coated by conductive polymer core-shell approach The former intercalation approach is a straightforward method in which poly34-ethylenedioxythiophene PEDOT has been inserted between the layers of V2O5 using a soft process of intercalation The process takes place through an in-situ polymerization of EDOT within the framework of crystalline V2O5 The insertion reaction results in a random layer stacking structure leading to broadening of the energy state distribution Electrochemical measurements indicated that the new hybrids showed reversible specific capacities up to ~330 mAhg at C10 in the potential range 20-44 V vs LiLi This improvement of electrochemical performance compared with pristine V2O5 is attributed to higher electric conductivity enhanced bi-dimensionality and increased structural disorder as well To account for these observations an electrochemical model which highlights the effect of structural disorder will be presented In the latter core-shell approach a polypyrrole PPYmaghemite hybrid was prepared by pyrrole polymerization on the maghemite nanoparticle surfaces Electrochemical measurements showed that contrary to microcrystalline one nanocrystalline maghemite exhibits a rather large electrochemical capacity in agreement with the proposed electrochemical model However only a partial reversibility was found In addition to capacity increase the polypyrrole-surface modification also enhanced the electrochemical reversibility of maghemite nanoparticles The hybrids delivered more than 300 mAhg in the potential range 13-43 V vs LiLi Effect of Annealing and of Cooling Rates on n-GaAs Electrode Photoelectrochemical Characteristicshttp://blogs.najah.edu/staff/hikmat-hilal/article/Effect-of-Annealing-and-Cooling-Rates-on-n-GaAS-Electrode-Photoelectrochemical-CharacteristicsPublished ArticlesActive and Passive Electronic Components 272 2004 69-80 H S Hilal S Saleh I Sadeddin and G Campet Enhancement of n-GaAs characteristics by combined heating, cooling rate and metalloporphyrin modification techniqueshttp://blogs.najah.edu/staff/hikmat-hilal/article/Enhancement-of-n-GaAs-characteristics-by-combined-heatingPublished ArticlesSolid State Sciences 6 2004139-146 H S Hilal W Ateereh T Al-Tel R Shubaitah I Sadeddin and G Campet Abstract Different modification techniques namely preheating controlling the cooling rate and modification with tetra-4-pyridylporphyrinatomanganese III have been used to enhance photoelectrochemical characteristics of n-GaAs electrodes in light-to-electricity conversions Combination of such three techniques together yielded electrodes with better darkcurrent density vs potential plots and photocurrent density vs potential plots Higher efficiency and stability were also observed for electrodes modified by such combined techniques 2003 Elsevier SAS All rights reserved n-GaAs Band-edge repositioning by modification with metalloporphyrin/polysiloxane matriceshttp://blogs.najah.edu/staff/hikmat-hilal/article/n-GaAs-Band-edge-repositioning-by-modification-with-metalloporphyrinPublished ArticlesActive and Passive Electronic Components 262003 1 H S Hilal M Masoud S Shakhshir N Jisrawi Modification of n-Si characteristics by annealing and cooling at different rateshttp://blogs.najah.edu/staff/hikmat-hilal/article/Modification-of-n-Si-characteristics-by-annealing-and-cooling-at-different-ratesPublished ArticlesActive and Passive Electronic Components 262003213 H S Hilal I Sadeddin S Saleh Elisabeth Sellier and G CampetBook \\"A Short Course on Group Theory\\"http://blogs.najah.edu/staff/hikmat-hilal/article/Book-quotA-Short-Course-on-Group-TheoryquotGeneral Posts Introductory Course on Group Theory and Chemical Applications 4300 Authors: Hikmat S Hilaland Abed Al-Hafez Sayda An-Najah N University West Bank Palestine Book Description: Group theory is conventionally taught in a one-semester course at the seniorgraduate level for science students For such a purpose many textbooks dealing with rigors of derivations and theorems have been written to give in-depth treatment For one reason or another scientists with no prior knowledge of group theory may need quick familiarity with the subject without mathematical derivation rigors This book has been written for this purpose The book is based on lecture notes given to seniorgraduate students who need to deal with bonding theories and spectroscopy without pre-knowledge of group theory Imprint: Novinka Table of Contents: Preface: Chapter 1: Symmetry Elements and Symmetry Operations Chapter 2: Symmetry Point Groups Chapter 3: Representations and Character Tables Chapter 4: Application to Chemical Bonding Chapter 5: Application to Vibrational Spectra Appendices: Appendix A: Introduction to Matrices Appendix B: Character Tables for Common Point Groups Index Series: Chemistry Research and Applications Binding: ebook Pub Date: 2011 1st quarter Pages: 6 x 9 NBC - C ISBN: 978-1-61122-281-4 Status: FP Status Code Description AN Announcing FM Formatting PP Page Proofs FP Final Production EP Editorial Production PR At Prepress AP At Press AV Available Available Options: Version: Download: Windows - English RAK CAM-RasAlkhaymah Center for Asdvanced Materialshttp://blogs.najah.edu/staff/hikmat-hilal/article/RAK-CAM-RasAlkhaymah-Center-for-Asdvanced-MaterialsGeneral PostsIWAM 2010 RAK-CAMRasalKhayma2010 Preparation characterization modification and application of nano-sized cadmium chalcogenide thin-films: enhancement of light conversion efficiency and stability Hikmat S Hilal and Iyad Saadeddin An-Najah N University Nablus West Bank Palestine Tel: 970-9-2945507 Fax:970-9-2387982 E-Mail: hikmathilal@yahoocom The work described here has been done in collaboration with: Rania Ismail Amer El-Hamouz Huda Sabri Subhi Saleh Maysaa Atatri Ahed Zyoud Ghazi Nour Mosa El-Hasan Israa Hamdan Abstract: In earlier studies we demonstrated new simple techniques to modify characteristics of monolithic semiconductor electrodes such as n-Si and n-GaAs in light-to-electricity conversions A combination of two methods namely: cooling rate and coverage with electro-active ions simultaneously enhanced both conversion efficiency and stability of the electrodes Due to preparation difficulty and high cost of highly pure monolithic electrodes research has recently been focused on thin-film semi-conducting SC material electrodes prepared by chemical bath deposition CBD However such thin-film electrodes suffer low efficiency of conversion and low stability under photo-electrochemical PEC conditions More research is thus needed to modify thin-film electrodes for future PEC applications To enhance efficiency and stability of new CBD-based thin-film SC electrodes we employed our earlier techniques cooling rate and electro-active species attachment to cadmium chalcogenide CdX: where X = S or Se thin-film electrodes The results are encouraging Both electrode efficiency and stability of CdS electrodes have been significantly enhanced Moreover CBD-based CdSe films which have not been described before in PEC systems has been prepared here and stabilized for the first time ever In this presentation details of preparation modification characterization electronic absorption spectra fluorescence spectra XRD and SEM results and PEC characteristic will be described Future perspectives of commercializing these results will also be discussed Key words: Solar energy CdS CdSe thin film electrodes References: 1 H S Hilal M Masoud S Shakhshir N Jisrawi n-GaAs Band-edge repositioning by modification with metalloporphyrinpolysiloxane matrices Active and Passive Electronic Components 26 2003 1 2 H S Hilal M Masoud S Shakhshir and N Jisrawi Metalloporphyrinpolysiloxane modified n-GaAs surfaces: Effect on PEC efficiency and surface stability J Electroanal Chem 527 2002 47-55 3 H S Hilal I Sadeddin S Saleh Elisabeth Sellier and G Campet Modification of n-Si characteristics by annealing and cooling at different rates Active and Passive Electronic Components 26 2003 213 4 H S Hilal S Saleh I Sadeddin and G Campet \Effect of Annealing and Cooling Rates on n-GaAS Electrode Photoelectrochemical Characteristics\ Active and Passive Electronic Components 272 2004 69-80 5 H S Hilal W Ateereh T Al-Tel R Shubaitah I Sadeddin and G Campet Enhancement of n-GaAs characteristics by combined heating cooling rate and metalloporphyrin modification techniques Solid State Sciences 6 2004139-146 6 J Portier H S HILAL I SAADEDDIN S J HWANG and G Campet THERMODYNAMIC CORRELATIONS AND BAND GAP CALCULATIONS IN METAL OXIDES Progress in Solid State Chemistry 32 20045 207 7 H S Hilal and J A Turner CONTROLLING CHARGE-TRANSFER PROCESSES AT SEMICONDUCTORLIQUID JUNCTIONS Electrochimica Acta 51 2006 64876497 8 Hikmat S Hilal Rania M A Ismail and Amer El-Hamouz \ Effect of cooling rate of pre-annealed CdS thin film electrodes prepared by chemical bath deposition: Enhancement of photo-electrochemical characteristics Electrochemica Acta 54 2009 34333440 9 Hikmat S Hilal Huda Sabri Iyad Sadeddin Ahed Zyoud and Subhi Saleh Photoelectrochemical processes based on FTOCdSe electrodes prepared by CBD: new techniques to stabilize CdSe electrodes Unpublished data 2009 10 Hikmat S Hilal Maysaa Jararah Musa Hassan Iyad Saadeddin Preparation characterization and stabilization of Zn-doped CdS thin film electrodes for photoelectrochemical processes Unpublished data 2009 hemical bath deposited CdSe nano-scale thin films for light-to-electricity conversion: a new approach to enhance efficiency and stabilityhttp://blogs.najah.edu/staff/hikmat-hilal/article/hemical-bath-deposited-CdSe-nano-scale-thin-films-for-light-to-electricity-conversion-a-new-approach-to-enhance-efficiency-and-stabilityGeneral Posts THE 2ND ISESCO INTERNATIONAL WORKSHOP AND CONFERENCE ON NANOTECHNOLOGY 2010 ICWN 2010 25 th 27th January 2010 Nanotechnology in Energy Materials and Health Sekretariat ICWN2010 Pusat Pengajian Fizik Gunaan Fakulti Sains dan Teknologi Universiti Kebangsaan Malaysia 43600 Bangi Selangor Malaysia Chemical bath deposited CdSe nano-scale thin films for light-to-electricity conversion: a new approach to enhance efficiency and stability Hikmat S Hilal Iyad Sadeddin Huda Sabri Subhi Saleh and Ahed Zyoud Department of Chemistry An-Najah N University Nablus West Bank Palestine Fax: 970-9-2387982 E-mail: hikmathilal@yahoocom Abstract: In earlier studies we demonstrated new simple techniques to modify characteristics of monolithic semiconductor electrodes such as n-Si and n-GaAs in light-to-electricity conversions A combination of two methods namely: cooling rate and coverage with electro-active ions embedded inside polymer matrices simultaneously enhanced both conversion efficiency and stability of the electrodes Due to preparation difficulty and high cost of highly pure monolithic electrodes research has recently been focused on thin-film semi-conducting SC material electrodes prepared by chemical bath deposition CBD However such thin-film electrodes suffer low efficiency of conversion and low stability under photo-electrochemical PEC conditions More research is thus needed to modify thin-film electrodes for future PEC applications To enhance efficiency and stability of new CBD-based thin-film SC electrodes we employed our earlier techniques cooling rate and electro-active species attachment to CdSe thin-film electrodes CBD-based CdSe films which have not been described before in PEC systems were prepared here and stabilized for the first time ever In this presentation details of preparation modification characterization and PEC characteristic will be described Future perspectives of commercializing these results will also be discussed References: 1 H S Hilal M Masoud S Shakhshir N Jisrawi n-GaAs Band-edge repositioning by modification with metalloporphyrinpolysiloxane matrices Active and Passive Electronic Components 262003 1 [UK English] 2 H S Hilal M Masoud S Shakhshir and N Jisrawi Metalloporphyrinpolysiloxane modified n-GaAs surfaces: Effect on PEC efficiency and surface stability J Electroanal Chem 527 200247-55 [Elsevier Netherland English] 3 H S Hilal I Sadeddin S Saleh Elisabeth Sellier and G Campet Modification of n-Si characteristics by annealing and cooling at different rates Active and Passive Electronic Components 26 2003 213 [in English] 4 H S Hilal S Saleh I Sadeddin and G Campet \Effect of Annealing and Cooling Rates on n-GaAS Electrode Photoelectrochemical Characteristics\ Active and Passive Electronic Components 272 2004 69-80 [in English] 5 H S Hilal W Ateereh T Al-Tel R Shubaitah I Sadeddin and G Campet Enhancement of n-GaAs characteristics by combined heating cooling rate and metalloporphyrin modification techniques Solid State Sciences 6 2004139-146 [Elsevier English] 6 J Portier H S HILAL I SAADEDDIN S J HWANG and G Campet THERMODYNAMIC CORRELATIONS AND BAND GAP CALCULATIONS IN METAL OXIDES Progress in Solid State Chemistry 32 20045 207 7 H S Hilal and J A Turner CONTROLLING CHARGE-TRANSFER PROCESSES AT SEMICONDUCTORLIQUID JUNCTIONS Electrochimica Acta 51 2006 64876497 8 Hikmat S Hilal Rania M A Ismail and Amer El-Hamouz \ Effect of cooling rate of pre-annealed CdS thin film electrodes prepared by chemical bath deposition: Enhancement of photo-electrochemical characteristics Electrochemica Acta 54 2009 34333440 9 Hikmat S Hilal Huda Sabri Iyad Sadeddin Ahed Zyoud and Subhi Saleh Photoelectrochemical processes based on FTOCdSe electrodes prepared by CBD: new techniques to stabilize CdSe electrodes Unpublished data 2009 10 Hikmat S Hilal Maysaa Atatreh Musa Hassan Iyad Saadeddin Preparation characterization and stabilization of Zn-doped CdS thin film electrodes for photoelectrochemical processes Unpublished data 2009 11 Hikmat S Hilal Ghazi Nour Ahed Zyoud Muath H Helal and Iyad sadeddin accepted Solid State Sciences 2009 Preparation, characterization, modification and application of thin-film cadmium chalcogenide semiconductors: enhancement of solar conversion efficiency and stabilityhttp://blogs.najah.edu/staff/hikmat-hilal/article/Preparation-characterization-modification-and-application-of-thin-film-cadmium-chalcogenide-semiconductors-enhancement-of-solar-conversion-efficiency-and-stabilityGeneral Posts Palestine Polytechnic University PPU 2nd International Conference on Energy and Environmental Protection in Sustainable Development November 10-12 2009 Hikmat S Hilal and colleagues Departmenet of Chemistry Najah University Abstract: In earlier studies we demonstrated new simple techniques to modify characteristics of monolithic semiconductor electrodes such as n-Si and n-GaAs in light-to-electricity conversions A combination of two methods namely: cooling rate and coverage with electro-active ions embedded inside polymer matrices simultaneously enhanced both conversion efficiency and stability of the electrodes Due to preparation difficulty and high cost of highly pure monolithic electrodes research has recently been focused on thin-film semi-conducting SC material electrodes prepared by chemical bath deposition CBD However such thin-film electrodes suffer low efficiency of conversion and low stability under photo-electrochemical PEC conditions More research is thus needed to modify thin-film electrodes for future PEC applications To enhance efficiency and stability of new CBD-based thin-film SC electrodes we employed our earlier techniques cooling rate and electro-active species attachment to cadmium chalcogenide CdX: where X = S or Se thin-film electrodes The results are encouraging Both electrode efficiency and stability of CdS electrodes have been significantly enhanced Moreover CBD-based CdSe films which have not been described before in PEC systems has been prepared here and stabilized for the first time ever In this presentation details of preparation modification characterization electronic absorption spectra fluorescence spectra XRD and SEM results and PEC characteristic will be described Future perspectives of commercializing these results will also be discussed Nanotechnology activities in Palestinehttp://blogs.najah.edu/staff/hikmat-hilal/article/Nanotechnology-activities-in-palestineGeneral PostsA Note from Hikmat S Hilal A survey on nanotechnology research activities in Palestine is needed by Arab nanotechnology Association I have been consulted a number of colleagues at Palestinian Universities in West Bank and Gaza Strip I have received some data from a number of colleagues but I still need to know more about ongoing activities I appeal to colleagues to send me information about nanotech research activities being conducted in Palestine My e-mail address is: hikmathilal@yahoocom Waiting to hearing from you Hikmat Nano-scale thin film enhancement http://blogs.najah.edu/staff/hikmat-hilal/article/Nano-scale-thin-film-enhancement-General PostsA Note from Hikmat S Hilal In one lecture Dr Sami El-Shal pointed out that microwave heating gives better control of shape and size of nanoparticle that are prepared as colloidal particles The question that comes out here is: can this technique be used to control shape and size of nano-scale polycrystals in thin films for the purpose of photovoltaic applications? We will try this technique at Najah N University Surface modification of semiconductor electrodes by metalloporphyrine ions: enhancement of band edge positions, stability and conversion efficiency in PEC processeshttp://blogs.najah.edu/staff/hikmat-hilal/article/Surface-modification-of-semiconductor-electrodes-by-metalloporphyrine-ions-enhancement-of-band-edge-positions-stability-and-conversion-efficiency-in-PEC-processes-1General PostsAbstract submitted to CIMTEC conference 5th FORUM ON NEW MATERIALSMontecatini Terme Italy to be heldJune 13-18 2010 Symposium FG-1 Photovoltaic Solar Energy Conversion: Materials andTechnology Challenges Surface modification of semiconductor electrodes by metalloporphyrine ions: enhancement of band edge positions stability and conversion efficiency in PEC processes Hikmat S Hilal Department of Chemistry An-Najah N University PO Box 7 Nablus Palestine Fax: 970-9-2387982 E-mail: hikmathilal@yahoocom Participants: Moayyad Masoud Wajdi Ateerih Samar Shakhshir Huda Sabri Maysaa Atatreh Iyad Saadeddin Ahed Zyoud Subhi Salih Mousa El-Hasan and others Abstract: Narrow band semiconductors are suitable catalysts for visible light-to-electricity conversions under photo-electrochemical PEC conditions but are unstable to such conditions Simple techniques have been developed to stabilize n-GaAS electrodes in PEC experiments Porphyirinatomanganese MnP as mixture of two different oxidation numbers MnII and MnIII complexes were chemically anchored to the electrode surface via anchoring ligands The modified n-GaAs electrodes showed enhanced conversion efficiencies Moreover the band edge positions were shifted toward more positive potentials This was manifested in photo current vs potential curves and in Mott-Schottky plots However the anchoring ligands and the attached ions peeled away from the electrode surface and the electrode stability could not be permanently retained by this technique A better technique was then developed Metalloporphyrine complexes embedded inside polysiloxane matrices were attached to n-GaAs electrodes The resulting n-GaAsPolysiloxaneMnP electrode systems showed enhanced conversion efficiency and stability at the same time The results are rationalized based on ability of the MnP system to behave as redox couple that catalyzes charge transfer at the electrodeliquid interface The technique is useful for other mono-lithic narrow band gap semiconductor electrodes such as n-GaInP2 Results on using this technique other types of semiconductor electrodes will also be presented Surface modification of semiconductor electrodes by metalloporphyrine ions: enhancement of band edge positions, stability and conversion efficiency in PEC processeshttp://blogs.najah.edu/staff/hikmat-hilal/article/Surface-modification-of-semiconductor-electrodes-by-metalloporphyrine-ions-enhancement-of-band-edge-positions-stability-and-conversion-efficiency-in-PEC-processesGeneral PostsAbstract submitted to CIMTEC conference 5th FORUM ON NEW MATERIALSMontecatini Terme Italy to be heldJune 13-18 2010 Symposium FG-1 Photovoltaic Solar Energy Conversion: Materials andTechnology Challenges Surface modification of semiconductor electrodes by metalloporphyrine ions: enhancement of band edge positions stability and conversion efficiency in PEC processes Hikmat S Hilal Department of Chemistry An-Najah N University PO Box 7 Nablus Palestine Fax: 970-9-2387982 E-mail: hikmathilal@yahoocom Participants: Moayyad Masoud Wajdi Ateerih Samar Shakhshir Huda Sabri Maysaa Atatreh Iyad Saadeddin Ahed Zyoud Subhi Salih Mousa El-Hasan and others Abstract: Narrow band semiconductors are suitable catalysts for visible light-to-electricity conversions under photo-electrochemical PEC conditions but are unstable to such conditions Simple techniques have been developed to stabilize n-GaAS electrodes in PEC experiments Porphyirinatomanganese MnP as mixture of two different oxidation numbers MnII and MnIII complexes were chemically anchored to the electrode surface via anchoring ligands The modified n-GaAs electrodes showed enhanced conversion efficiencies Moreover the band edge positions were shifted toward more positive potentials This was manifested in photo current vs potential curves and in Mott-Schottky plots However the anchoring ligands and the attached ions peeled away from the electrode surface and the electrode stability could not be permanently retained by this technique A better technique was then developed Metalloporphyrine complexes embedded inside polysiloxane matrices were attached to n-GaAs electrodes The resulting n-GaAsPolysiloxaneMnP electrode systems showed enhanced conversion efficiency and stability at the same time The results are rationalized based on ability of the MnP system to behave as redox couple that catalyzes charge transfer at the electrodeliquid interface The technique is useful for other mono-lithic narrow band gap semiconductor electrodes such as n-GaInP2 Results on using this technique other types of semiconductor electrodes will also be presented