Nickel-cobalt alloy nanosheet-decorated three-dimensional titanium dioxide nanobelts electrodeposited on titanium meshes for boosting selective nitrate electroreduction to ammonia.

Electrocatalytic nitrate reduction reaction presents a promising avenue for environmentally friendly ammonia (NH) synthesis and wastewater treatment. An essential aspect to consider is the meticulous design of electrocatalysts. This study explores the utilization of a Ni-Co alloy nanosheet-decorated three-dimensional titanium dioxide (3D-TiO) nanobelts electrodeposited on titanium meshes (NiCo@TiO/TM) for efficient electrocatalytic NH production. The optimized NiCo@TiO/TM electrode achieves a significant NH yield of 676.3 ± 27.1 umol h cm with an impressive Faradaic efficiency (FE) of 95.1 % ± 2.1 % in a 0.1 M KOH solution containing 0.1 M NO at -0.4 V versus the reversible hydrogen electrode. Additionally, the electrode demonstrates exceptional electrochemical activity for NH synthesis in simulated wastewater, delivering an outstanding NH yield of 751.6 ± 44.3 umol h cm with a FE of 96.8 % ± 0.4 % at the same potential of -0.4 V. Moreover, the electrode exhibits minimal variation in current density, NH yields and FEs throughout the 24-h stability test and the 20-cycle test, demonstrating its excellent stability and durability. This study offers a straightforward electrodeposited approach for the development of 3D-nanostructured alloys as catalysts for NH electrosynthesis from nitrates at room temperature.