Dopant‐Induced Electronic States Regulation Boosting Electroreduction of Dilute Nitrate to Ammonium

Abstract

AbstractElectrochemically converting NO3− into NH3 offers a promising route for water treatment. Nevertheless, electroreduction of dilute NO3− is still suffering from low activity and/or selectivity. Herein, B as a modifier was introduced to tune electronic states of Cu and further regulate the performance of electrochemical NO3− reduction reaction (NO3RR) with dilute NO3− concentration (≤100 ppm NO3−−N). Notably, a linear relationship was established by plotting NH3 yield vs. the oxidation state of Cu, indicating that the increase of Cu+ content leads to an enhanced NO3−‐to‐NH3 conversion activity. Under a low NO3−−N concentration of 100 ppm, the optimal Cu(B) catalyst displays a 100 % NO3−‐to‐NH3 conversion at −0.55 to −0.6 V vs. RHE, and a record‐high NH3 yield of 309 mmol h−1 gcat−1, which is more than 25 times compared with the pristine Cu nanoparticles (12 mmol h−1 gcat−1). This research provides an effective method for conversion of dilute NO3− to NH3, which has certain guiding significance for the efficient and green conversion of wastewater in the future.