Cobalt Hydroxide Modification of TiO2 Nanosheets for Visible-Light-Responsive Photocatalysts

High Resolution Image Download MS PowerPoint Slide To make full use of sunlight for water splitting reactions for hydrogen production, a visible-light-driven photocatalyst was developed by modifying TiO 2 nanosheets with Co(OH) 2 . By adding an aqueous Co(NO 3 ) 2 ·6H 2 O solution to a TiO 2 nanosheet suspension, the TiO 2 nanosheets aggregated and Co(OH) 2 was formed. In the ultraviolet–visible (UV–vis) diffuse reflectance spectrum of the photocatalyst, new absorption bands attributable to Co(OH) 2 and the interfacial charge transfer between Co(OH) 2 and the TiO 2 nanosheets appeared at around 600 and 400 nm, respectively. The photocatalytic activity of Co(OH) 2 /TiO 2 nanosheets was evaluated in terms of the O 2 evolution reaction in an aqueous AgNO 3 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) 2 /TiO 2 nanosheets proceeds via Co(OH) 2 photocatalysis and interfacial charge transfer between Co(OH) 2 and the TiO 2 nanosheets under visible light irradiation.