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

Nanosize WS₂ sensitized mesoporous TiO₂ was prepared to extend the adsorption of the wide band gap TiO₂ into visible light region. Compared with nonporous particle TiO₂ substrate, it was found that the existence of mesopore is important for larger amount of WS ₂ loading and inhibition of the light-induced detachment of WS ₂ particles from the TiO₂ substrate during photocatalytic reaction, which leads to higher photocatalytic activity and 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 TiO ₂ could be neglected. In this case, deposition of Pt at the surface of semiconductor is indispensable for efficient hydrogen production.