Construction of Low‐Cost Z‐Scheme Heterostructure Cu2O/PCN for Highly Selective CO2 Photoreduction to Methanol with Water Oxidation

Solar‐driven CO2 reaction with water oxidation into alcohols represents a promising approach to achieve real artificial photosynthesis. However, rapid recombination of photogenerated carriers seriously restricts the development of artificial photosynthesis. Herein, a facile method is explored to construct low‐cost Z‐Scheme heterostructure Cu2O/polymeric carbon nitride (PCN) by in situ growth of Cu2O hollow nanocrystal on PCN. The protective PCN layer and Z‐schematic charge flow can make robust Cu2O/PCN photocatalysts, and the spatial separation of electrons and holes with high redox potentials of ECB (−1.15 eV) and EVB (1.65 eV) versus NHE can efficiently drive CO2 photoreduction to methanol in pure water, which is further confirmed by DFT calculation. The Z‐scheme heterostructure Cu2O/PCN exhibits a high methanol yield of 276 µmol g−1 in 8 h with ca. 100% selectivity, much superior to that of isolated Cu2O and PCN, and all the reported Cu2O‐based heterostructures. This work provides a unique strategy to efficiently and selectively promote the conversion of CO2 and H2O into high‐value chemicals by constructing a low‐cost Z‐scheme heterostructure.