The electrochemical nitrate reduction by using boron-doped diamond (BDD) and copper (Cu) electrodes was investigated at various potentials. Product selectivity of nitrate reduction was strongly dependent on the applied potential for both electrodes. The highest selectivity of nitrogen gas production was obtained at −2.0 V (vs. Ag/AgCl) by using a BDD electrode with a faradaic efficiency as high as 45.2%. Compared with Cu electrode, nitrate reduction on BDD electrode occurred at more positive potential, and the production of nitrogen gas was larger. The transformation of surface-adsorbed nitrate into molecular nitrogen would be accelerated on BDD electrode with hindering nitrite production. In addition, low concentration of surface-adsorbed hydrogen on the BDD would also retard the ammonia generation, leading to increase in the selectivity of nitrogen gas formation. Meanwhile, BDD electrode could hinder the hydrogen evolution reaction, which enhanced the efficiency for nitrate reduction and decreased energy consumption. BDD electrode has excellent stability to remain better performance for reducing nitrate during electrolysis without any variation of surface morphology or chemical components.

在各种电势下，研究了通过使用掺硼金刚石（BDD）和铜（Cu）电极进行电化学硝酸盐还原的方法。硝酸盐还原的产物选择性在很大程度上取决于两个电极的施加电势。在-2.0 V（vs。Ag / AgCl），使用法拉第效率高达45.2％的BDD电极。与铜电极相比，BDD电极上的硝酸盐还原发生在更高的正电位，并且氮气的产生量更大。在BDD电极上会加速表面吸附的硝酸盐向分子氮的转化，从而阻碍亚硝酸盐的产生。另外，BDD上低浓度的表面吸附氢也会阻碍氨的产生，从而导致氮气形成的选择性增加。同时，BDD电极可能会阻碍氢的释放反应，从而提高了硝酸盐还原的效率并降低了能耗。