Synthesis and characterization of CuO/Co0304 and CuO/Fe:O; composites and their potential application in the photocatalytic CO2 reduction process

Abstract

Cupric oxide is a prominent material used as a photocatalyst due to its narrow bandgap; coupling it with other metal oxide semiconductors improves its efficiency due to the favored charge transference. This work reports the synthesis of the composites CuO/CosO4 and CuO/Fex0s, prepared in a sol-gel and hydrothermal two-step methodology to disperse the cocatalyst particles over CuO. The effect of the cocatalyst's concentration over CuO in its structural, optical, and photocatalytic properties was analyzed. A better distribution of the Fe203 particles over CuO was observed, which resulted in the largest cfficiency in the photocatalytic CO2 reduction to formic acid. Despite this, increasing the cocatalyst concentration reduces the photocatalytic activity due to the surface saturation, probably causing the formation of recombination centers. The presented methodology represents a low-cost way to obtain highly efficient composites in photocatalytic reductive processes.