Ni-doped Co3O4 catalysts with various Ni concentrations (0.01, and 0.015 M) were synthesized using a simple, cost-effective hydrothermal route. The samples are denoted as Co3O4-1 Co3O4-2. Structural morphological properties of as-prepared characterized by XRD, FTIR, XPS, SEM, HR-TEM techniques. electrochemical characteristics for the urea oxidation (UOR) on catalyst examined cyclic voltammetry ...