Rapid plasma preparation of CuO nanowires for efficient ammonia synthesis

Abstract

The conversion of nitrate into high-value ammonia (NH3) by electrochemical means can significantly reduce environmental pollution and alleviate the energy crisis. The development of easily prepared, high-performance electrocatalysts and understanding the origins of their catalytic activity are crucial. In this study, we rapidly prepared an electrocatalyst (P-CuO-10/CF) using plasma technology, subsequently employed under neutral and low nitrate concentration conditions for electrochemical ammonia synthesis. In situ Raman spectroscopy revealed that the as-prepared material underwent an in situ phase transformation to CuO/Cu, its actual active phase, and the transformed CuO exists in an amorphous structure. This heterogeneous structure demonstrated superior nitrate conversion performance, achieving an ammonia yield of 3.57 mg h–1 cm−2 at -0.6 V vs RHE and a Faradaic efficiency of 95.7 %. This strategy expands the application scope of copper-based materials in electrocatalysis and highlights the promising uses of plasma-prepared materials for electrocatalytic nitrate reduction to generate NH3.