Enhanced oxygen evolution and urea oxidation reaction using a nanosheet-structured NiO@P-doped carbon composite as an anode catalyst

Abstract

One promising approach to solving energy and environmental problems is urea electrolysis. In order to catalyze the urea oxidation process (UOR), we were able to successfully construct a NiO hierarchical nanosheet on a P-doped carbon layer (NiO@PC). Because of the increased electrical conductivity and the widespread practice of using the direct electro-oxidation mechanism to initiate the UOR, NiO@PC is a good substitute for valuable metals like IrO₂ because it has UOR activity that is on par with the most active modern catalysts. The outermost layer of P-doped carbon enhanced Ni–O bond fabrication at the anion–cation interface; because of this, the NiO@PC hierarchical nanosheet initiates the UOR process with a lower onset-potential (1.30 V vs. RHE) than the Ni(OH)₂ nanosheet. The NiO@PC nanosheet acts as a reaction site during the UOR process for the generated NiOOH rather than the NiO phase, although both the NiOOH and the NiO phase operate as active sites during the OER process. This study contributes to our comprehension of the UOR mechanism and creates a new path for the development of affordable P-doped carbon UOR catalysts based on Ni.