Shape- and size-selective photocatalytic reactions by layered titanic acid powder suspended in deaerated aqueous alcohol solutions

Abstract

Protonic titanate of H_xTi_2−x/4Z_x/4O₄ ·H₂O (HLe; x≃0.7, Z = vacancy) powder of a layered crystal structure was prepared, suspended in aqueous alcoholic solutions and photoirradiated by light of wavelength >300 nm at room temperature under a deaerated atmosphere. HLe showed photocatalytic activity of H₂ production, similar to ordinary titanium(IV) oxide powders. The rate and time course of H₂ evolution by HLe depended strongly on the kind of alcohol. Detailed investigation revealed that the photocatalytic activity was regulated by the shape and size of the alcohol, due to the selection of adsorption at the interlayer of HLe.