Bi2S3/In(OH)3 heterojunction for enhanced CO2 electroreduction to formic acid

Electroreduction of CO2 for formic acid production has been regarded as an efficient option for CO2 utilization. However, under high current, achieving high selectivity for formic acid is challenging, which cannot meet industrial demands. Herein, we reported a type of Bi/In(OH)3 (BIO) heterojunction reconstructed from Bi2S3/ In(OH)3 during electrochemical process, in which In(OH)3 was applied to modulate the electronic structure of Bi. This strategy efficiently enhanced the *OCHO intermediates adsorption and lead to a decent selectivity towards formic acid under high current density. BIO displays faraday efficiency of formic acid beyond 95 % across a wide range current density of 200-400 mA cm-2 , where the highest value reached 97.7 % at 400 mA cm-2 . This work clarified the mechanism of CO2 electroreduction to HCOOH on heterojunction, guiding the design of advanced catalysts.