Hydrogen production from water splitting under visible light irradiation using sensitized TiO₂-ZrO₂ mixed oxide photocatalysts

Abstract

Alternative energy resources, especially hydrogen, are now being considered as an ideal energy supplies. Photocatalytic water splitting is a promising process for producing hydrogen, by using solar light as an energy source and using water as a feedstock. This research was focused on the hydrogen production from the photocatalytic. water splitting under visible light irradiation using Eosin Y-sensitized Pt-loaded mesoporous-assembled TiO₂-ZrO₂ mixed oxide photocatalysts, of which the mesoporous-assembled TiO₂-ZrO₂ with various Ti-to-Zr molar ratios were synthesized by a sol-gel process with the aid of a structure-directing surfactant. Various parameters affecting the photocatalytic activity, including calcination conditions, phase composition, and amount and method of Pt loading, were studied. The experimental results showed that without Pt loading, the TiO₂-ZrO₂ photocatalyst with a Ti-to-Zr molar ratio of 95: 5 calcined at 800℃ provided the maximum photocatalytic hydrogen production activity. Moreover, the Pt loading by a photochemical deposition method (PCD) was found to greatly enhance photocatalytic activity of the TiO₂-ZrO₂ photocatalyst more than that by a single-step sol-gel method (SSSG).