Electrocatalytic activity survey of some cathode materials for the reduction of nitrites and nitrates in aqueous solution

The electrochemical techniques are increasingly recognized for their effectiveness in environmental remediation due to their efficiency and selectivity, positioning them as some of the cleanest methods for treating contaminants without producing sludge or unwanted byproducts. This study aims to compare the performance of various cathode materials for the electro-reduction of nitrites and nitrates from aqueous solutions. The materials examined included copper, graphite, stainless steel, and zinc. Through systematic testing, copper emerged as the most effective cathode for reducing both nitrites and nitrates. We further optimized key operational parameters, establishing them at a scan rate of 50 mV/s, an initial effluent concentration of 100 mg/L, a pH of 7, and a potential range of [-1, +1] V/SCE in cyclic voltammetry. Under these optimal conditions, we achieved notable reduction efficiencies, with yields of 96.5% for nitrites and 99% for nitrates after 45 minutes. These findings underscore the potential of specific cathode materials and optimized parameters in enhancing the efficiency of electrochemical methods for treating aqueous ion pollutants.