Promoting CO₂ electroreduction on CuO nanowires with a hydrophobic Nafion overlayer

Copper-based materials could produce a series of products through the CO₂ electroreduction reaction, and are regarded as the most promising catalysts to produce fuels and value-added chemicals using renewable energy sources. However, the competitive hydrogen evolution reaction (HER) is a daunting challenge for the selectivity of carbonaceous products. Here, a hydrophobic electrode surface was constructed by modifying the CuO nanowire electrode with a thick Nafion overlayer, which exhibited enhanced selectivity toward the CO₂ RR (especially for CO) and suppressed HER activity. This work highlights the importance of hydrophobicity in the selectivity of CO₂ reduction and hints at the additional role of Nafion in powder-based catalyst electrodes.