H2 production of (CdS–ZnS)–TiO2 supported photocatalytic system

Abstract

Mixed semiconductor (CdS–ZnS)–TiO2(1 : 1 : 1) mixture system over different supports like MgO, CaO, γ-Al2O3, SiO2 and modified MgO and CaO, have been prepared, characterized and tested for H2 production in a S2−+45 degree ruleSO2−3 mixture solution. (CdS–ZnS)–TiO2(D) over MgO support wherein the TiO2 taken is from Degussa (D) sample gives 206.7 μmol+45 degree ruleh of H2 production and this catalyst sustain the H2 production rate for longer durations. Dopants like Li2O, Cs2O or K2O make MgO and CaO supports act like super basic oxide when they are doped and in turn increase the photocatalytic activity. The (CdS–ZnS)–TiO2(I) system wherein the TiO2 taken from Titanium Isopropoxide, supported on 20 wt% Li2O doped CaO is found to give 209.8 μmol+45 degree ruleh rate of H2 production. Characterization studies like UV-Visible spectra, X-ray Diffraction spectra and Scanning Electron Microscope photographs were taken for all the catalysts and the data generated over these samples is evaluated. A scheme of H2S photocatalytic decomposition of ZnCdS–TiO2(D+45 degree ruleI) over different supports in the presence of S2−+45 degree ruleSO2−3 substrate, is proposed indicating the formation of thiosulfate cycle at this heterojunction. © 1999 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.