Moreover, Cu 2 O/WO 3 -001 composite exhibited higher photocatalytic activity for CO 2reduction than that of Cu 2 O/WO 3 catalyst and the W 5+ content kept a lower value thanthose in other catalysts, which implied that the dominant (0 0 1) facets in WO 3 -001nanosheet could inhibit the reduction of W 5+ in composites.