The charge redistribution induced by Cu-Co bimetallic synergies efficiently promotes electrochemical reduction to ammonia

The Haber-Bosch process for ammonia synthesis is energy-intensive and environmentally damaging, while nitrate wastewater poses risks to both the environment and human health. Utilizing electrochemical method could remove nitrate in the sewage and a part of nitrate would been reduced to ammonia provided a highly efficient approach for nitrate removal and ammonia synthesis. In this study, incorporated Cu and Co on boron-nitrogen-doped graphite (BCN) substrate with eminent conductivity synthesized BCN-CuCo catalyst. On the catalyst, Cu and Co gave rise to synergistic effect which aroused charge redistribution between Cu and Co, which facilitated the nitrate adsorption, accelerated catalytic kinetics for nitrate reduction. BCN-CuCo catalyst demonstrated eminent performance for nitrate reduction, achieving a high Faradic efficiency of 95.8 % at −0.46 V vs RHE and an impressive ammonia yield rate of 12321.6 μg h −1 mg cat -1 at −0.86 V vs RHE in 0.5 M H 2 SO 4 with 0.1 M KNO 3 . It also showed excellent performance in HNO 3 and neutral media, expanding its application scope. Ultimately, the BCN-CuCo facilitated the production of 320 mg of ammonium diuranate in a neutral medium, supporting sustainable resource utilization. This research provides an efficient strategy for ammonia synthesis and introduces a method for recycling resources from uranium and nitrate-contaminated wastewater.