Nanostructured Ni2P-C as an Efficient Catalyst for Urea Electrooxidation

Graphical Cheap and cheerful : Nanostructured Ni 2 P−C was demonstrated as an efficient catalyst for urea electrooxidation. The material exhibited an excellent catalytic ability and was found to display improved charge-transfer kinetics towards urea electrooxidation. Nickel-based materials are a type of cost-effective catalyst for urea oxidation. Herein, we first reported nanostructured Ni 2 P−C as an efficient catalyst for urea electrooxidation. The Ni 2 P−C catalyst was prepared by a facile hydrothermal method and the structure and morphology were further characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The hexagonal crystal structure for Ni 2 P was indicated by the characteristic peaks in the XRD patterns, and lattice fringes of Ni 2 P were clearly observed in the high-resolution TEM images. The catalytic ability for urea electrooxidation was studied by cyclic voltammetry and chronoamperometry techniques. It was found that the current density at 0.5 V was ca. 70.4 mA cm −2 , about 2.7 times higher than that of the referenced commercial nickel oxide catalyst. A good catalytic stability for urea oxidation was also obtained. A diffusion-controlled process was observed for urea oxidation on Ni 2 P catalyst while the active sites arising from Ni(II) ion oxidation was following a surface-redox-reaction-controlled process. Kinetics studies by impedance spectroscopy and Tafel slope analysis displayed improved charge-transfer kinetics towards urea electrooxidation. The results demonstrated that Ni 2 P would have potential applications for catalytic urea oxidation.