Redispersion of exsolved Cu nanoparticles on LaFeO3 photocatalyst for tunable photocatalytic CO2 reduction

Excessive exploitation and depletion of fossil fuels have led to the escalation of CO2 emissions, which are responsible for global climate deterioration. Cu-based solid catalysts can transform CO2 into various hydrocarbons via a sustainable photocatalytic pathway. Herein, we fabricated a Cu-decorated LaFeO3 photocatalyst using a sequential in situ exsolution (in H2)/redispersion (in N2) strategy. The dispersion of Cu was significantly enhanced (∼3 times), i.e., from 13.8 % (exsolved) to 41.4 % (redispersed). The combined theoretical and experimental results confirmed the successful formation of uniformly dispersed Cu active sites for efficient CO2 adsorption and photocatalytic conversion. The enhancement of light absorption and manipulation of the band structure were also collectively achieved, offering an optimized catalyst involving superior CO and CH4 production compared to its counterparts. In addition, photocatalytic water splitting was significantly suppressed, suggesting high selectivity of the photocatalytic pathway. This study offers a new perspective on the design principle of photocatalysts for selective CO2 conversion.