Electrodeposition-Fabricated Flexible Copper Electrodes for Electrocatalytic Nitrate Reduction

With the vigorous development of the field of electrocatalytic nitrate reduction, new requirements have been put forward for reactor structures and electrode adaptability. However, traditional rigid electrodes hinder industrial-scale applications. This study presents a novel flexible porous copper electrode, which is prepared through a deposition process on conductive foam substrate. This electrode ingeniously combines structural durability with high catalytic activity, making it a promising candidate for electrocatalytic nitrate reduction. Our initial research delved into the deposition nucleation kinetics of copper. The results revealed that within the deposition potential range of −0.3 V to −0.6 V, electrodeposition predominantly followed an instantaneous nucleation model. At low copper ion concentrations, the progressive nucleation model was mainly observed, while a transition towards instantaneous nucleation occurred as the copper ion concentration increased. By optimizing reaction parameters, we successfully fabricated a CuF@PUS electrode with a unique cubic structure using a cyclone electrolysis reactor. This electrode demonstrated outstanding electrocatalytic performance in nitrate reduction. In comparison to the control copper foam electrode, it exhibited a significantly lower overpotential (less than 300 mV). After a 20 h stability test, the CuF@PUS electrode maintained a high nitrate removal rate of 92.52%, underscoring its robustness and long-term operational stability.