Efficient photoelectrocatalysis of CO2 for C2+ production by bridged structure Cu2O-BiOBr heterojunction

Cuprous oxide (Cu 2 O) is a promising material for photoelectrocatalytic CO 2 reduction (PEC-CO 2 RR); however, its widespread application is hindered by issues such as photocorrosion, structural instability, and low selectivity toward desirable products. In this work, a Cu 2 O-BiOBr nanohybrid catalyst with excellent visible light responsiveness are successfully developed using energy band structure matching and morphology modulation strategies. This heterostructure exhibits a three-dimensional bridge-like architecture composed of interwoven one-dimensional nanorods and two-dimensional nanosheets. Cu 2 O acts as a surface electron-rich active center, while BiOBr functions as both a co-catalyst and photogenerated electron storage, enabling efficient photoelectrocatalytic conversion of CO 2 under visible light irradiation. That is, the optimized Cu 2 O-BiOBr-2 catalyst achieves a C 2+ Faraday efficiency (FE) of 51% at −0.6 V vs. RHE, which is 2.55 times exceeding the pure Cu 2 O catalysts, The findings obtained from in-situ spectroscopic characterization reveal that the efficient transport channel of the constructed heterojunction enhances charge transfer efficiency at the catalyst interface and boosts redox capacity, improving both efficiency and stability of Cu 2 O in PEC-CO 2 RR. This work provides new insights for constructing novel heterojunctions.