Shape-Dependent Performance of Cu/Cu 2 O for Photocatalytic Reduction of CO 2 .

The photocatalytic conversion of CO 2 into solar fuels or chemicals is a sustainable approach to relieve the immediate problems related to global warming and the energy crisis. This study concerns the effects of morphological control on a Cu/Cu 2 O-based photocatalyst for CO 2 reduction. The as-synthesized spherical Cu/Cu 2 O photocatalyst exhibits higher activity than the octahedral one under visible light irradiation. The difference in photocatalytic performance between these two catalysts could be attributed to the following two factors: (1) The multifaceted structure of spherical Cu/Cu 2 O favors charge separation; (2) octahedral Cu/Cu 2 O only contains more positively charged (111) facets, which are unfavorable for CO 2 photoreduction. The results further highlight the importance of utilizing crystal facet engineering to further improve the performance of CO 2 reduction photocatalysts.