Cobalt Hydroxide Modification of TiO Nanosheets for Visible-Light-Responsive Photocatalysts.

To make full use of sunlight for water splitting reactions for hydrogen production, a visible-light-driven photocatalyst was developed by modifying TiO nanosheets with Co(OH). By adding an aqueous Co(NO)·6HO solution to a TiO nanosheet suspension, the TiO nanosheets aggregated and Co(OH) was formed. In the ultraviolet-visible (UV-vis) diffuse reflectance spectrum of the photocatalyst, new absorption bands attributable to Co(OH) and the interfacial charge transfer between Co(OH) and the TiO nanosheets appeared at around 600 and 400 nm, respectively. The photocatalytic activity of Co(OH)/TiO nanosheets was evaluated in terms of the O evolution reaction in an aqueous AgNO solution, finding that the reaction proceeds under visible light. Furthermore, the investigation of the wavelength dependence of the photocatalytic activity revealed that the photocatalytic reaction on Co(OH)/TiO nanosheets proceeds via Co(OH) photocatalysis and interfacial charge transfer between Co(OH) and the TiO nanosheets under visible light irradiation.