WS2 sensitized mesoporous TiO2 for efficient photocatalytic hydrogen production from water under visible light irradiation

Nanosized WS2 sensitized mesoporous titanium dioxide (TiO2) was prepared to extend the adsorption of the wide band gap TiO2 into visible light region. Compared with TiO2, substrate without mesopores, it was found that the mesoporous substrate is beneficial for larger amount of WS2 loading and inhibition of the light-induced detachment Of WS2 particles from the substrate during photocatalytic reaction, which leads to higher photocatalytic activity and better stability. We also found that the rate-determining step for photocatalytic hydrogen production is the transfer of electrons from TiO2 substrate to H+ in solution, when the recombination between electrons and holes within TiO2 could be neglected. In this case, deposition of Pt at the surface of semiconductor is indispensable for efficient hydrogen production. (c) 2006 Elsevier B. V. All rights reserved.