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.