Proceedings of the 4th International Conference onNanostructures (ICNS4)12-14 March 2012, Kish Island, I.R. Iran

Abstract Book |INST| Sharif University of Technology| 128

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This research deals with investing of the effect of order mesoporous carbon CMK-3 as a support on Pt catalyst activities and dissociation of hydrogen molecules and enhanced hydrogen adsorption on modi-fied MIL-101 in ambient temperature. The isotherm of these unmodi-fied and modified samples is investigated using volumetric method at 298K and the pressure ranging from 1-20 bar. Also the synthesized

S. Mandegarzada, M. Anbiab*, E. Motaeea

a Research Laboratory of Advanced Materials, Chemistry and Chemical Engineering Research Center of Iran, Tehran14335-186, Iranb Research Laboratory of Nanoporous Materials, Faculty of Chemistry, Iran University of Science and Technology, Tehran 16846, Iran*anbia@iust.ac.ir

Synthesis of Pt/CMK-3 Catalyst for Enhanced Hydrogen Storage in MIL-101 by Hydrogen Spillover Effect

In this work, we report on fabrication and characterization of solid-state dye-sensitized solar cells (ss-DSC) based on TiO2 hollow sphere/nanoparticle composite electrodes. TiO2 hollow sphere (HSs) were pre-pared by a facile sacrificial templating method, then it was grounded and added in different ratios to TiO2 nanoparticle (NP) paste, from which composite HS/NP electrodes were fabricated. The composite TiO2 films include hollow spheres of 300-700 nm. By optimizing the amount of HSs in the paste, 40% improvement in efficiency was obtained in com-parison to ss-DSC utilized pure NP electrodes. By increasing the frac-tion of HSs in the electrode the current density increased by 56% (from 2.5 to 3.9 mA.cm-2). Electron transport and lifetime measurements were performed to investigate the photovoltaic performance of ss-DSCs. Composite electrodes have enhanced light absorption since the size of the hollow spheres is in the range of visible light. Electron transport time and electron lifetime have significantly improved because of dif-ferent trap distribution of HSs. The charge collection efficiency was en-hanced significantly over a wide range of electron energy distribution, leading to improvement in the performance of solar cells.Keywords: Solid state dye sensitized solar cells; Hollow sphere; P3HT; Charge collection efficiency

G.Sadoughia, R. Mohammadpoura, A. Irajizada, b*, N. Taghaviniaa, b, Sh. Dadgostarc, F. TajabadibaInstitute for Nanoscience and Nanotechnology, Sharif University of Tech-nology, Tehran, 14588-89694, IranbDepartment of Physics, Sharif University of Technology, Tehran, 11155-9161, IrancDepartment of Physics, Faculty of Sciences, TarbiatModares University, Tehran, 14155-4838, Iran*Iraji@sharif.edu

Investigation on Photovoltaic Performance of Hollow Sphere/nanoparticle Composite TiO2 Electrodes for Solid state Dye Sensitized Solar Cells

Mesoporous TiO2 films with different thicknesses were prepared for dye sensitized solar cell application using dip coating method. The crystal structure and morphology of the films were studied by scan-ning electron microscope and X-ray diffraction. The optical proper-ties of the films were investigated through UV–Vis absorption. With increasing film thickness from 3.1 to 13.9 μm, the efficiency increases from 0.81 to 3.09 %.Keywords: TiO2; Dye sensitized solar cell; Dip coating method

M. Abdi Jalebi, A. M. Bakhshayesh, M. R. Mohammadi *Department of Materials Science and Engineering, Sharif University of Technology, Tehran, Iran*mohammadi@sharif.ir

Mesoporous TiO2 Electrodes with Different Thickness for Dye Sensitized Solar Cell Application

Transparent fluorine-doped tin oxide (FTO) is replaced with chromium as the substrate of photoanode in a dye sensitized solar cell (DSC). The effect of Cr substrate treatment with a 1%wt amorphous sol of TiO2(with nanoparticles less than 10 nm) on cell performance is stud-ied. Scanning electron microscopy (SEM) images show that this layer is a compact layer that increases interconnections between mesoporous layer of TiO2 and rough electrodeposited layer of Cr. Current-voltage measurement reveals that this deposition increases efficiency of cell up to 90% of initial value (for a 3-4 µm layer, from 0.78 % to 1.48%).Keywords: Dye sensitized solar cell; Amorphous sol of TiO2; Chro-mium electrodeposition

F. Behrouznejad, N. Taghavinia*Department of Physics, Sharif University of Technology, Tehran, 11155-9161, Iran*Taghavinia@sharif.edu

Dye Sensitized Solar Cell with Chromium Substrate for Photoanode: Enhanced Efficiency by Amorphous TiO2 Sol Treatment

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In the present study, we report preparation of TiO2 thin films using electrophoretic deposition (EPD) of nanoparticles from two alcoholic media, ethanol and pentanol, for the fabrication of dye-sensitized solar cells (DSSC). The microstructure of the films formed by this process is investigated by scanning electron microscope (SEM) that showed a non-uniform porous layer is obtained in ethanol; however, deposition from the titanium dioxide/pentanol suspension resulted in the formation of a relatively uniform microstructure. The optical microscopy (OM) analysis confirms that we obtain crack-free layes with a thickness of 12 µm. Ultraviolet–visible (UV–Vis) spectra of adsorbed dye on the two layers show that more dye is loaded on

A.A. Sadeghi*, T. Ebadzadeh, B. Raissi, S.M.A.FateminiaCeramic department, Material and Energy Research Center, Karaj, 316-31787, Iran *sadeghi.ali.a@gmail.com

Fabrication and Comparison of Dye Sensitized SolarCells using Electrophoretically Deposited TiO2 Nanopar-ticles in Ethanol and Pentanol Suspensions

the layer deposited in ethanol. Current–voltage (I-V) characteristics of the cells indicate that for the case of the cells made by the layer formed in ethanol, the internal resistance of the cell is more than that of pentanol medium which would decrease the efficiency of the cell. This difference was attributed to the reduction of effective surface area and also the loss of particles interconnection as a result of the presence of aggregates within the layer obtained in ethanol.Keywords: Electrophoretic deposition, DSSC, Ethanol, Pentanol

Proceedings of the 4th International Conference onNanostructures (ICNS4)12-14 March 2012, Kish Island, I.R. Iran

Abstract Book |INST| Sharif University of Technology| 129

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Au:WO3 nanocomposite thin film photoanodes have been synthesized using a simple low cost sol-gel method. Au concentration varied from 0 to 20 mol% in the samples. Scanning electron microscopy (SEM) images showed formation of big islands with a typical size of 600 µm including nanoprticles of 50 nm in diameter. Based on Atomic force microscopy (AFM) observations, the samples with 1mol% Au has the highest sur-face roughness and effective surface.X-ray photoelectron spectroscopy (XPS) analysis showed by increasing Au concentration, concentration of Au1+ chemical state increased on the surface. The best photoelectro-chemical performance was observed for the sample containing 1 mol% Au leading to generation of hydrogen with a rate of about 2.4 µmol h-1.Keywords: Ionic state, surface interface; Charge transport resistance; Hydrogen generation, Peroxide

N. Naseria, A.Z. Moshfegha, b *a Department of Physics, Sharif University of Technology, 11155-9161, Teh-ran, Iranb Institute for Nanoscience and Nanotechnology, Sharif University of Tech-nology, 14588-89694, Tehran, Iran*moshfegh@sharif.edu

Au:WO3 Nanocomposite Thin Film Photoanodes for Photoelectrochemical H2 Production via Water Splitting

improve the homogeneity of nanocomposite. MWCNTs were synthe-sized by chemical vapor deposition (CVD). Cyclic voltammetry (CV) measurements were utilized at potential ranging from -1.6 to +0.6 V (vs Ag/AgCl), to study the electrochemical hydrogen storage behavior of nanocomposite material. Hydrogen adsorption/desorption occurred in -1.0 and 0.0 V, respectively.Keywords: Hydrogen; MWCNTs; Composite; Ni nanoparticles

An electroless deposition technique was used to decorate Multi-walled carbon nanotubes (MWCNTs) with Ni nanoparticles. Electrochemical hydrogen storage behaviour of prepared nanocomposite was studied.Nanocomposite electrode was prepared by mixing this nanocomposite with micro hydride resin composite.Acetone was added as solvent to

N. Rahimia, M.M. Doroodmandb, c*, S. Sabbaghia, M. H. Sheikhica Nano Chemical Engineering Department, Shiraz University, Shiraz, Iranb Chemistry Department, Shiraz University, Shiraz, Iranc Nanotechnology Research Institute, Shiraz University, Shiraz, Iran*Doroodmand@shirazu.ac.ir

Fabrication of Ni Attached MWCNTs through Electroless Deposition Technique: Investigation of Electrochemic-alHydrogen Evolution

Present article is an attempt to develop methods to increase the con-ductivity of polyaniline (PANi) nanofibers. Herein, an approach for synthesis of Ag nanoparticle-incorporated PANi nanofibers was em-ployed. Interfacial synthesized PANi nanofibers were dissolved in hydrochloric acid (HCl) solution and used as seeds to afford the po-lymerization of aniline and therefore manufacture PANinanofibers. Also, transition metal-doped PANi nanofibers were chemically pre-pared by adding inorganic salts (e.g. MnSO4, CuSO4) as the additives via a self-assembly process. High conductivity was observed for these metal-PANi nanofiber composites at room temperature against single PANi nanofibers, which was previously reported. The conductivity of samples was measured; also scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and UV–Visspectroscopy were applied for the characterization of the products. Finally, viability of the composites to use as electrode materials for supercapacitor application was tested by electrochemical methods.Keywords: Polyaniline nanofiber; Nanoparticles; Seeding polymer-ization; Supercapacitor

S. H. Kazemia*, R. Mohamadia, L. Eskandarianb, A. A. SafariaaDepartment of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran, b Department of Textile Engineering, Amirkabir University of Technology, Tehran, Iran *habibkazemi@iasbs.ac.ir

Fabrication of Metal-Polyaniline Nanofiber Composites for Energy Storage Applications

samples are characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD) and scanning electron microscopy (SEM) meth-ods. Through these modification with Pt (20wt%)/CMK-3 and carbon bridge, the hydrogen uptake is almost twice that of pristine sample. The storage capacity of modified MIL-101 at 20 bar and 298 K are found to be 1.34wt% which are significantly improved as compared to the pure MIL-101. Because the Pt nanoparticles are uniformly distrib-uted inside the mesopores of CMK-3 supports. Therefore Pt catalytic activities in dissociation of hydrogen molecules was improved which was leading to significant changes in hydrogen sorption properties in room temperature.Keywords: Hydrogen adsorption; Pt/CMK-3; MIL-101; Hydrogen spillover effect; Ambient temperature

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Desalination technologyis a constant source to produce water and to overcome the water shortage in the dry and desert areas and near-sea countries. Application of new technologies (such as nanotechnology) is a possible method to improve the performance of sand filter in drip irri-gation system. In this paper, Rice husk ash (RHA) and almond husk ash (AHA) were produced in 2 sizes miliparticles and nanoparticles. Two volumes percent, 10 and 20, were considered for mixing the particles with sand filter. Saline water (12 dSm-1) was entered into the sand filter, placed in a Plexiglas’s container, under two flow rates of 3 and 6 m3hr-1. Electrical conductivity (EC), sodium (Na+), Calcium (Ca2+), carbonate (CO3

2-), bicarbonate (HCO3-), chloride (Cl-), magnesium(Mg2+), sul-phate (SO4

2-), hardness, sodium adsorption ratio (SAR), pH were mea-sured in the outlet water. The results showed, after using nanoparticles, we had a remarkable reduction in chemical parameters in the outlet water. The highest removal (93.6%) was related to AHA nanoparticles with 10% volume and flow rateof 6 m3hr-1. With the flow rateof 3 m3hr-1 the highest rate of EC reduction, were obtained 94.2 and 93 percent, using 10 and 20 percent of RHA, respectively.Keywords: Desalination; Saline water; Rice husk ash; Almond husk ash

J. Abedi-Koupai*, E.Mohri-EsfahaniDepartment of Water Engineering, College of Agriculture, Isfahan Univer-sity of Technology, 84156-83111, Isfahan, Iran* koupai@cc.iut.ac.ir

Desalination of Water Using Nanoparticles of Husk Ashes in Sand Filter