Preparation of visible light photocatalyst by interface reaction between tungsten-molybdenum oxide and copper clusters

A tungsten-molybdenum solid solution oxide ((Mo,W)O3) powder was prepared using hydrothermal processing. The crystal structure of the obtained powder was orthorhombic WO3 type with 0.22M H2O per unit chemical formula weight. This powder was dehydrated and transformed into monoclinic WO3 type structure by heat treatment at 500°C in air. When uncalcined powder was modified with Cu by impregnation with a CuCl2 solution and subsequent firing at 500°C in air, photocatalytic decomposition activity against gaseous 2-propanol (IPA) was achieved under visible light illumination. Results suggest that Cu(W1−xMox)O4 was formed on the (Mo,W)O3 powder surface by the Hedvall effect during its phase transition, and that the Z-scheme became feasible between (Mo,W)O3 and Cu(W1−xMox)O4. •(Mo,W)O3 powder was prepared using hydrothermal processing.•The crystal structure of the obtained powder was orthorhombic WO3 type.•Cu-modification to (Mo,W)O3 elicited photocatalytic activity under visible light.•The Hedvall effect during firing formed Cu(W1−xMox)O4 on the (Mo,W)O3 surface.•The Z-scheme became feasible between (Mo,W)O3 and Cu(W1−xMox)O4.