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

The photocatalytic conversion of CO2 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/Cu2 O-based photocatalyst for CO2 reduction. The as-synthesized spherical Cu/Cu2 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/Cu2 O favors charge separation; (2) octahedral Cu/Cu2 O only contains more positively charged (111) facets, which are unfavorable for CO2 photoreduction. The results further highlight the importance of utilizing crystal facet engineering to further improve the performance of CO2 reduction photocatalysts.