Controlled Synthesis of Copper Sulfide-associated Catalysts for Electrochemical Reduction of CO2 to Formic Acid and Beyond: A Review

Converting carbon dioxide (CO2) into value-added chemicals is considered as a promising strategy to mitigate climate change. Among the various CO2 reduction techniques, electrochemical CO2 reduction (ERCO2) using renewable energy sources holds significant potential. Consequently, the design and development of electrocatalysts capable of offering both high performance and cost-effectiveness hold the potential to expedite reaction kinetics and facilitate widespread industrial adoption. In recent years, abundant copper sulfide (Cu/S)-associated nanomaterials among various metal-chalcogenides have been of extensive research interest due to their semiconductor and low toxicity properties, enabling them to be used in widespread applications of the ERCO2 field. This review highlights the progress of engineered Cu/S-associated nanomaterials for ERCO2 reactions and elaborates on the correlations of engineering strategies, catalytic activity, and reaction pathways. The paper also summarises the controllable synthesis methods for fabricating various state-of-the-art Cu/S-associated structures and outlines their possible implementation for CO2 reduction as an electrocatalyst. Finally, challenges and prospects are presented for the future development and practical application of Cu/S-associated catalysts for ECO2R to value-added chemicals.