The (0 0 1)facet of hexagonal phase WO 3 nanosheet was in favor of the H 2 O oxidation in the CO 2 reduction process. Additionally, the Z-scheme charge transfer mode of Cu 2 O/WO 3 heterojunction could promote photoinduced charge separation and enhance redox ability of the separated electrons and holes, leading to excellent photocatalytic CO 2 reduction performance.