ZHANG Chenfei ^{1, 2}, MA Jingling ^{1, 2}, JIA Xingliang ^{1, 2}, FU Lixiang ^{1, 2}, ZHANG Zhikang ^{1, 2}

(1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471000,
Henan, China; 2. Research Center for High Purity Materials, Henan University of Science and Technology,
Luoyang 471000, Henan, China)

Abstract: Bimetallic NiCo-ZIF-67 nanocrystals were prepared by using an ordinary solution method, as precursor to obtain NiCo/NC-X. X-ray diffraction (XRD), tungsten filament scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), transmission scanning electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize surface morphology, phase, chemical element distribution and surface chemical bond valence states of the samples. ORR/OER electrocatalytic properties and stability of the materials were studied by using linear sweep voltammetry (LSV) and other electrochemical testing methods. It is observed that the limiting current density of NiCo/NC-800 at 800 ℃ is 4.26 mA·cm⁻², which is close to the ORR performance of commercial Pt/C. The overpotential of NiCo/NC-800 is 469.6 mV at 10 mA·cm⁻² and the corresponding Tafel slope is 98.68 mV·dec⁻¹, which has higher OER performance than commercial RuO₂ and sufficiently high stability.

Key words: bifunctional electrocatalysis; ZIF-67; bimetal; porous carbon; nitrogen doped