Boosting Electrochemical Nitrate Reduction to Ammonia by Fe Doped CuO/Co₃O₄ Nanosheet/Nanowire Heterostructures

The electrochemical nitrate reduction reaction (NO₃ ^-RR) is a novel green method for ammonia synthesis. The development of outstanding NO₃ ^-RR performance is based on reasonable catalyst. Metal oxides have garnered significant attention due to their exceptional electrical conductivity and catalytic properties. Doping serves as an effective strategy for enhancing catalyst performance due to its ability to change the electron cloud distribution and energy levels. In this study, we develop a heterojunction catalyst Fe doped copper oxide nanosheet and cobalt tetroxide nanowire growing on carbon cloth simultaneously (Fe-CuO@Co₃O₄/CC) via hydrothermal method. The well-designed Fe-CuO@Co₃O₄/CC has excellent NH₃ yield (470.9 μmol h^-1 cm^-2) and Faraday efficiency (FE: 84.4 %) at -1.2 V versus reversible hydrogen electrode (vs. RHE). The heterostructure increases the specific surface area of the catalyst, and the possibility of contact between the catalyst and NO₃ ^- ions, enhances the catalytic efficiency. In addition, the catalyst has excellent stability and can stably carry out the electrocatalytic nitrate reduction reaction (NO₃ ^-RR), which provides a way for further research on the high-efficiency reduction of nitrate.