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Nickel-based materials have been extensively reported to be highly effective for the electrochemical oxidation of urea in wastewater, which is critical for energy utilization as well as contamination elimination. In this study, two Ni-containing materials of nickel-aluminum layered double bydroxides (NiAl-LDH) and metal organic framework (Ni-MOF) were synthesized and compared with Ni disk toward urea oxidation reaction (UOR). Physical characterization proved the existence of Ni with the same valence of +2 in the as-prepared catalysts. Moreover, the electrochemical analysis showed that higher surface concentrations of 1.01×10-6 and 1.17×10-6 mol/cm2 existed in both NiAl-LDH and Ni-MOF, which was significantly higher than Ni disk of 3.74×10-7 mol/cm2. Moreover, Ni-MOF was found to be a better catalyst due to its lower activated energy, Tafel slope, and overpotential as well as higher current density and turnover frequency value than NiAl-LDH. This phenomenon might be explained by the protection of Ni2+ by the lattice of layered double hydroxides, which led to an obstacle for its transformation to Ni3+ and thus obviously hindered UOR.

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