Recent advances in Cu-based nanocomposite photocatalysts for CO₂ conversion to solar fuels

CO₂ conversion via photocatalysis is a potential solution to address global warming and energy shortage. Photocatalysis can directly utilize the inexhaustible sunlight as an energy source to catalyze the reduction of CO₂ to useful solar fuels such as CO, CH₄, CH₃OH, and C₂H₅OH. Among studied formulations, Cu-based photocatalysts are the most attractive for CO₂ conversion because the Cu-based photocatalysts are low-cost and abundance comparing noble metal-based catalysts. In this literature review, a comprehensive summary of recent progress on Cu-based photocatalysts for CO₂ conversion, which includes metallic copper, copper alloy nanoparticles (NPs), copper oxides, and copper sulfides photocatalysts, can be found. This review also included a detailed discussion on the correlations of morphology, structure, and performance for each type of Cu-based catalysts. The reaction mechanisms and possible pathways for productions of various solar fuels were analyzed, which provide insight into the nature of potential active sites for the catalysts. Finally, the current challenges and perspective future research directions were outlined, holding promise to advance Cu-based photocatalysts for CO₂ conversion with much-enhanced energy conversion efficiency and production rates.