Shape‐Dependent Performance of Cu/Cu2O for Photocatalytic Reduction of CO2

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/Cu2O‐based photocatalyst for CO2 reduction. The as‐synthesized spherical Cu/Cu2O 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/Cu2O favors charge separation; (2) octahedral Cu/Cu2O 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. Pull shapes: Spherical Cu/Cu2O exhibits higher activity than octahedral Cu/Cu2O for CO2‐H2O conversion under visible light irradiation. This is ascribed to the following: 1) the multifaceted spherical structure enables increased charge separation; 2) octahedral Cu/Cu2O only contains more positively charged (111) facets, which are unfavorable for CO2 photoreduction.