Surface-modified copper foam for nitrate-to-ammonia and zinc-nitrate fuel cell catalysis

Electrochemical reduction of nitrate to ammonia is a promising method for treating nitrate-containing wastewater and synthesizing high-value-added ammonia. However, the low catalytic efficiency of electrocatalysts and the complex process of catalyst preparation hinder the practical application and development of nitrate-to-ammonia conversion. In this work, Cu rearrangement on the surface of copper foam (CF) was achieved through a surface reconstruction engineering strategy, resulting in the construction of a high-performance NO₃RR electrocatalytic electrode (Cu@CF). Benefiting from the ideal structural advantages, the performance of Cu@CF in NO₃RR was significantly improved, with NH₃ production rates reaching up to 7.9 mg h^-1 cm^-2 and a Faradaic efficiency of 92.3%. Furthermore, the zinc-nitrate fuel cell assembled with Cu@CF and zinc foil also showed excellent fuel cell performance, with an output voltage of up to 1.4 V and power density of 3.9 mW cm^-2. This study has reference value for the development of efficient, stable and inexpensive NO₃RR electrodes.