Design and Electrochemical Evaluation of Cu/Cu₂O–SGr–Bi₂S₃ Nanohybrids for Enhancing CO₂ Electroreduction

Rouhollahi, Ahmad; Fouladvand, Maral; Bakhshi, Elaheh

doi:10.22034/abec.2025.733510

Design and Electrochemical Evaluation of Cu/Cu₂O–SGr–Bi₂S₃ Nanohybrids for Enhancing CO₂ Electroreduction

Document Type : Original Article

Authors

Ahmad Rouhollahi

Maral Fouladvand

Elaheh Bakhshi

Department of Analytical Chemistry, Faculty of Chemistry, K.N. Toosi University of Technology, 15418-49611, Tehran, Iran

10.22034/abec.2025.733510

Abstract

The electrochemical conversion of carbon dioxide (CO₂) represents a promising strategy for reducing greenhouse gas emissions and facilitating sustainable chemical production. Here, we present a rationally engineered copper foam electrode integrated with a multifunctional nanohybrid comprising copper oxide (Cu₂O), bismuth sulfide (Bi₂S₃), and sulfur-doped graphene (SGr–Bi₂S₃). The Cu/Cu₂O–SGr–Bi₂S₃ composite leverages synergistic electronic and catalytic interfaces, resulting in outstanding electrocatalytic performance for CO₂ reduction. Comprehensive physicochemical and electrochemical analyses, including cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy, demonstrate that the hybrid electrodes deliver significantly higher cathodic current densities and exhibit markedly reduced charge transfer resistance under CO₂-saturated conditions compared to unmodified copper counterparts. The nanoscale distribution of Bi₂S₃ effectively increases the density of active catalytic sites, while strong electronic coupling at the heterointerfaces suppresses the competing hydrogen evolution reaction. As a result, the Cu/Cu₂O–SGr–Bi₂S₃ nanohybrids achieve superior activity, enhanced current densities, and excellent operational stability, outperforming conventional copper-based electrodes. These results position the Cu/Cu₂O–SGr–Bi₂S₃ nanohybrids as highly efficient, scalable, and economically viable electrocatalysts for next-generation CO₂ reduction technologies.

Keywords

Electrochemical Characterization

Sulfur-doped graphene

CO₂ reduction

Electrocatalysis

Cu/Cu₂O&ndash

SGr&ndash

Bi₂S₃ electrodes

Stability

Subjects