Construction of Low-Cost Z-Scheme Heterojunction Cu2O/PCN-250 Photocatalysts Simultaneously for the Enhanced Photoreduction of CO2 to Alcohols and Photooxidation of Water

Abstract

Solar-driven high-efficiency conversion of CO₂ with water vapor into high-value-added alcohols is a promising approach for reducing CO₂ emissions and achieving carbon neutrality. However, the rapid recombination of photogenerated carriers and low CO₂ adsorption capacity of photocatalysts are usually the factors that limit their applicability. Herein, a series of low-cost Z-scheme heterostructures Cu₂O/PCN-250-x are constructed by in situ growth of ultrasmall Cu₂O nanoparticles on PCN-250. A systematic investigation revealed that there is a strong interaction between Cu₂O nanoparticles and PCN-250. The resulting Cu₂O/PCN-250-2 exhibits excellent photogenerated carrier separation efficiency and CO₂ adsorption capacity, which dramatically promote the conversion of CO₂ into alcohols. Notably, the total yield of 268 μmol g_cat^-1 for the production of CH₃OH and CH₃H₂OH is superior to that of isolated PCN-250 and Cu₂O. This study provides a new perspective for the design of a Cu₂O nanoparticle/metal-organic framework Z-scheme heterojunction for the reduction of CO₂ to alcohols with water vapor.