Interface engineering of Cu2O/In(OH)3 for efficient solar-driven CO2 electrochemical reduction to syngas

Electrochemical carbon dioxide reduction reaction (CO2RR) holds greater promise for converting CO2 into value-added chemicals, but designing and manufacturing efficient CO2RR catalysts remains desirable but challenging. Here, the Cu2O/In(OH)3 with heterojunction structure was prepared as an efficient CO2RR electrocatalysts. The optimized Cu2O/In(OH)3–1:1 stabilizes over a wide range of potentials to generate syngas (hydrogen/carbon monoxide, H2/CO) at a ratio of 2:1, and the total Faraday efficiency (FE) remains close to 100 %. However, the ratio of syngas will change to 1:1 when the Cu/In ratio becomes 1:2. In addition, creatively using solar energy to drive the CO2RR system can directly and efficiently achieve the change of solar energy to chemical energy (syngas). Moreover, in-situ experiments show that part of Cu+ is converted to Cu during the CO2RR process, while In(OH)3 remains stable. This work highlights an efficient electrocatalyst for producing syngas based on interface engineering.