Advanced Ag NPs integrated N and P-doped porous carbon (NPC) Nanocatalyst: A breakthrough in sustainable ammonia synthesis from nitrate wastewater

A significant problem in the environmental production of NH₃ in liquid form and the reduction of global water pollutants is the development of stable and durable electrocatalysts that can efficiently drive the conversion of nitrate to ammonia in electrochemical systems. An electrocatalyst with remarkable durability and activity was synthesized using pyrolysis to enhance the effectiveness of the electrocatalytic reduction of nitrate. This catalyst consists of nanostructured silver (Ag) integrated into carbon doped with nitrogen and phosphorus (NPC) and adhered to carbon paper (CP). The characterization results confirm the creation of the nanostructured Ag@NPC and elucidate how Ag and NPC have powerful synergistic interactions. Such interactions significantly increase the overall number of sites for catalysis and electrical conductivity. Attaining a Faradaic efficiency of 96.14 % and an ammonia yield rate of 0.0145 mmol/h.cm² at −1.655 V relative to SCE. The synthesized electrocatalyst remarkably reduces electrocatalytic nitrate (NO₃⁻). Furthermore, the Ag@NPC nanocomposite demonstrated remarkable durability and extended stability. A study utilizing isotope labeling technologies suggested that ammonia generation resulted from nitrate reduction. The Ag@NPC is an efficient electrocatalyst for the remediation of nitrate-contaminated wastewater, facilitating the effective extraction of ammonia. This recovered ammonia can be utilized for multiple industrial applications, highlighting the versatility and effectiveness of the nanocomposite in mitigating environmental pollutants.