Efficient and stable electroreduction of CO2 to CH4 on CuS nanosheet arrays

Converting CO2 into value-added hydrocarbon fuels has attracted enormous interest due to the advantage of simultaneously addressing major energy and environmental issues. Here we report on copper sulfide nanosheet arrays supported on nickel foam (CuS@NF) applied as a robust catalyst for CO2 electroreduction. A high faradaic efficiency of 73 ± 5% and a low Tafel slope of 57 mV dec−1 for CH4 formation were achieved. Moreover, the CuS nanosheets showed a stable CO2 electroreduction capability up to 60 h. The high performance of CuS@NF for CO2 electroreduction was ascribed to the nanosheet morphology as well as the presence of S species. This work illustrates how to design efficient and stable copper chalcogenide electrocatalysts for generating carbon-based fuels.