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Visible‐light response photocatalytic water splitting over CdS/TiO 2 and CdS–TiO 2 /metalosilicate composites
Author(s) -
Khatamian M.,
Saket Oskoui M.,
Haghighi M.,
Darbandi M.
Publication year - 2014
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.3186
Subject(s) - photocatalysis , materials science , composite number , visible spectrum , composite material , hydrothermal circulation , water splitting , aluminosilicate , dispersion (optics) , chemical engineering , hydrothermal synthesis , crystallite , nanotechnology , chemistry , catalysis , metallurgy , optoelectronics , optics , physics , biochemistry , engineering
SUMMARY In this work, we have synthesized two different phases of CdS nanoparticles, CdS/TiO 2 composites and their supported form on ZSM‐5 type metalosilicates (ferrisilicate and aluminosilicate) as CdS–TiO 2 /metalosilicate composites. The photocatalytic performance of these samples was evaluated by monitoring the amount of hydrogen evolved from water under visible‐light irradiation. The supported composites of TiO 2 –CdS/metalosilicate exhibited a higher photocatalytic activity in the photocatalytic water splitting than that of CdS/TiO 2 composites under visible‐light irradiation, suggesting an important role of support. Metalosilicate as a support, which can offer a very high surface area, provides effective and homogenous dispersion of the CdS/TiO 2 composite on the external surface or within the pores of metalosilicate and inhibits agglomeration of the formed composite. We observed that using the solvothermal method for the synthesis of CdS and the hydrothermal method for the synthesis of CdS/TiO 2 or CdS–TiO 2 /metalosilicate results in the enhancement of the photocatalytic activity of these composite compared with other procedures, which has been reported previously. We have realized that the support of the CdS/TiO 2 composite on ferrisilicate enhances the photocatalytic activity; however, using aluminosilicate as a support results in the abatement of the photocatalytic activity in comparison with the unsupported composite. This can be attributed to the presence of partially occupied ‘d’ orbitals in the electronic configuration of Fe 3+ in the structure of ferrisilicate which can interact with TiO 2 molecular orbitals. This interaction leads to the effective distribution of the composite on the support and the decreasing crystallite size of the composite and then enhancement of the photocatalytic activity. Copyright © 2014 John Wiley & Sons, Ltd.