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 ₃ ) 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 ₂ ) nanobelts electrodeposited on titanium meshes (Ni _x Co _y @TiO ₂ /TM) for efficient electrocatalytic NH ₃ production. The optimized Ni ₁ Co ₃ @TiO ₂ /TM electrode achieves a significant NH ₃ yield of 676.3 ± 27.1 umol h ^-1 cm ^-2 with an impressive Faradaic efficiency (FE) of 95.1 % ± 2.1 % in a 0.1 M KOH solution containing 0.1 M NO ₃ ^- at -0.4 V versus the reversible hydrogen electrode. Additionally, the electrode demonstrates exceptional electrochemical activity for NH ₃ synthesis in simulated wastewater, delivering an outstanding NH ₃ yield of 751.6 ± 44.3 umol h ^-1 cm ^-2 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 ₃ 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 ₃ electrosynthesis from nitrates at room temperature.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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