Synthesis of carbon-based catalysts with stability using Cu-BTC as precursor for electrocatalytic nitrate reduction

Background: Electrocatalytic nitrate reduction reaction (ENRR) to recyclable ammonia has become a green treatment NO3- technology for wastewater. However, poor stability of Cu-based electrocatalysts hinders their application. Methods: In this study, three derived catalysts were prepared using Cu-BTC as a precursor at different temperatures: Cu@C-250, Cu@C-350, and Cu@C-450. The catalysts' activity was investigated through a series of nitrate reduction performance tests, and the reaction mechanism was explored through various characterization methods. Significant findings: The batch ENRR test revealed that Cu@C-350 exhibited the best performance in terms of NO3- removal rate (73.70 %) and faradaic efficiency for NH4+ (80.01 %) at -0.58 V vs. RHE. EIS and oS analyses show that Cu+ accelerates electron transfer, reduce interfacial resistance, and interact with catalytic carriers to enhance the adsorption of NO3-. Additionally, the durability as an electrocatalyst is verified by consecutive cycling tests. Therefore, the use of roasted carbon material derivatives as electrocatalysts for the purification of nitrate-contaminated wastewater is a reliable strategy.