Decoration of In nanoparticles on In2S3 nanosheets enables efficient electrochemical reduction of CO2.

As a promising candidate for CO2 electroreduction, metal chalcogenides suffer from limited carrier density, which hampers the electron transport of electrocatalysts and activation of CO2. Herein, we have modified In2S3 nanosheets by in situ forming metallic In nanoparticles for enhanced CO2 electroreduction. The In-In2S3 hybrid nanosheets exhibited a remarkable geometrical current density of 70.3 mA cm-2 at -1.1 V vs. RHE, with 62.1 mA cm-2 for the carbonaceous product. The faradaic efficiency of the In-In2S3 hybrid nanosheets for the carbonaceous product reached 90% at -1.0 V vs. RHE, including 76% for formate production and 14% for CO production. The mechanistic study revealed that the improved performance by forming In nanoparticles on In2S3 nanosheets originated from the increased carrier density of the electrocatalysts and the decreased work function, which benefited the CO2 activation.