Characterization and Photocatalytic Activity of ZnO, ZnS, ZnO/ZnS, CdO, CdS and CdO/CdS Nanoparticles in Mesoporous SBA-15

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Grinding (solvent-free) method was used as a superior technique to prepare mesoporous photocatalysts of ZnO, ZnS, ZnO / ZnS, CdO, CdS and CdO / CdS-SBA-15. In this technique, the nitrate, acetate and chloride salts of zinc and/or cadmium were grinded with as-synthesized SBA-15 as a mesoporous material. The controllable sulfurationis was used to prepare ZnS, ZnO/ZnS, CdS and CdO/CdS-SBA-15 at temperature of 80 °C. The advantages of grinding technique were: i) the elimination of solvent and thus decrease of expense and ii) the complete incorporation of metal salts in the nanochannel of mesoporous material in a short time. X-ray powder diffraction, N2 adsorption-desorption and FT-IR spectroscopy were used to characterize the prepared materials. The highly dispersed semiconductors in SBA-15 demonstrate an active photodegradation of Congo red in aqueous solution. The nanocomposites of ZnO/ZnS and CdO/CdS in channels of SBA-15 showed the highest photocatalytic activity. The photocatalytic activity of ZnO-, ZnS- and ZnO/ZnS-SBA-15 were also dependent on the salt precursor of zinc. The prepared composite photocatalysts of zinc/SBA-15, by using ZnCl2 as salt precursor, indicated the higher activity.