Urea electrooxidation using ZIF-67-derived Co3O4 catalyst

The development of highly efficient and inexpensive electrocatalysts exhibiting long-term stability is essential for energy-related applications. In this work, the Co3O4 catalyst was synthesized by annealing ZIF-67. The as-prepared catalysts were characterized by XRD, XPS, SEM, and TEM. The electro-oxidation activities were measured by cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). In urea electro-oxidation (UOR), the ZIF-67-derived Co3O4 catalyst showed a lower Tafel-slope value (134 mV dec−1) than ZIF-67. The Co3O4 electrocatalyst had a higher electrochemical active surface area (ECSA) than ZIF-67, and therefore, it exhibited a higher electrocatalytic performance. CA also revealed that the ZIF-67-derived Co3O4 electrocatalyst exhibited a superior current density than ZIF-67 and exhibited consistent electrocatalytic activity for UOR.