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

Abstract

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 Cu₂ O/polymeric carbon nitride (PCN) by in situ growth of Cu₂ O hollow nanocrystal on PCN. The protective PCN layer and Z-schematic charge flow can make robust Cu₂ O/PCN photocatalysts, and the spatial separation of electrons and holes with high redox potentials of E_CB (-1.15 eV) and E_VB (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 Cu₂ O/PCN exhibits a high methanol yield of 276 µmol g^-1 in 8 h with ca. 100% selectivity, much superior to that of isolated Cu₂ O and PCN, and all the reported Cu₂ O-based heterostructures. This work provides a unique strategy to efficiently and selectively promote the conversion of CO₂ and H₂ O into high-value chemicals by constructing a low-cost Z-scheme heterostructure.