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

Protonic titanate of H(x)Ti(2-x/4)Z(x/4)O(4).H2O (HLe; x similar or equal to0.7, 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 H-2 production, similar to ordinary titanium(IV) oxide powders. The rate and time course of H-2 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.