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

We have confirmed a simple NaBH 4 reduction method for designing efficient electrocatalysts for interface engineering synthesis of Cu 2 O/In(OH) 3 heterojunctions. The H 2 /CO ratio can be changed from 2:1 to 1:1 by changing the Cu/In ratio. Simultaneously creatively utilizing solar energy to drive CO 2 RR systems while still maintaining excellent performance. [Display omitted] • The synthesis of catalysts (Cu 2 O/In(OH) 3 heterojunction) by one-step reduction with NaBH 4 provides a simple method for interface engineering. • The syngas (H 2 /CO) ratio can be changed from 2:1 to 1:1 within a wide potential range by changing the Cu/In feeding ratio. • Cu 2 O/In(OH) 3 showed high durability, minimal activity attenuation, and no significant change in H 2 /CO ratio after 16 h test. • Creatively using solar energy to drive the CO 2 RR system can directly and efficiently achieve the conversion of solar energy to chemical energy (syngas). • In-situ experiments and detailed characterization show that some Cu+ converts to Cu0 and In remains stable during the CO 2 RR process. Electrochemical carbon dioxide reduction reaction (CO 2 RR) holds greater promise for converting CO 2 into value-added chemicals, but designing and manufacturing efficient CO 2 RR catalysts remains desirable but challenging. Here, the Cu 2 O/In(OH) 3 with heterojunction structure was prepared as an efficient CO 2 RR electrocatalysts. The optimized Cu 2 O/In(OH) 3 –1:1 stabilizes over a wide range of potentials to generate syngas (hydrogen/carbon monoxide, H 2 /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 CO 2 RR 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 CO 2 RR process, while In(OH) 3 remains stable. This work highlights an efficient electrocatalyst for producing syngas based on interface engineering. [ABSTRACT FROM AUTHOR]