Facile Synthesis of Cu-Doped In ₂ S ₃ Microflower Catalyst for Electrochemical CO ₂ Reduction to Energy Fuels in a Wide Potential Range

Enhancing the activity of electroreduction of CO2 to valuable products and suppressing the hydrogen evolution reaction in aqueous solution are the major challenges nowadays for researchers. Indium-based materials demonstrate excellent catalytic behavior toward CO2 electroreduction, and incorporation of the Cu element into In2S3 brings better catalytic properties, provides enhanced electrochemical surface area, and provides higher charge transfer ability compared to the pristine material. Electrocatalytic techniques of the Cu doped In2S3 were performed in an H-cell reactor, and the most efficient electrocatalyst was identified for the CO2 reduction study. The electrocatalyst, 5% Cu doped In2S3, can reduce CO2 to methanol and formate with 34 and 36% Faradaic Efficiency (%FE), respectively, at −1.331 V vs RHE, and the corresponding partial current density values are −11.96 and −10.83 mA/cm2. The remarkable stability of the electrocatalyst during a 50 h of long-term chronoamperometry test further illustrates the excellent efficiency of the electrocatalyst. Density functional theory (DFT) based computational studies were employed to calculate the Density of States (DOS) of pristine In2S3 and 5% Cu doped In2S3 catalysts, as well as the free energies of intermediate product species for the generation of different carbon-based products.