Elevated electrocatalytic activity of high-efficiency urea induces water electrolysis via a ruthenium nickel oxynitride electrocatalyst

Urea oxidation plays a role in the application of nickel components as living catalysts in energy transporters. Here, ruthenium-doped nickel oxynitride was synthesized with a hydrothermal method on a supported carbon nanotube (Ru@NiON/CNT) at 130 °C and annealed in a nitrogen environment at 300 °C. The synthesis of Ru@NiON/CNT was confirmed by X-ray absorption spectroscopy and X-ray diffraction. Ru@NiON/CNT undergoes relatively strong charge-transfer transition and exhibits substantial redox characteristics, as shown by the electrochemical activity of a Ru@NiON/CNT electrocatalyst toward urea oxidation in an alkaline solution. The catalyst showed evidence of efficient oxygen evolution reaction and urea oxidation reaction capabilities, generating potentials of 1.51 and 1.27 V (vs Ag/AgCl), respectively, at a current density of 10 mA. A two-cell electrolyzer in alkaline for water and urea splitting using platinum–carbon and Ru@NiON/CNT as the cathode and anode, respectively, required a durability performance of 10 mA cm−2 and a cell voltage of 1.68 and 1.45 V. These findings offer an innovative strategy to explore stable and affordable non–noble metal electrocatalysts for use in renewable energy conversion technologies.