Mixed-metal MOF-derived Co-doped Ni3C/Ni NPs embedded in carbon matrix as an efficient electrocatalyst for oxygen evolution reaction

The exploration of electrocatalysts with high oxygen evolution reaction (OER) activity is highly desirable and remains a significant challenge. Transition metal carbides (TMCs) have been investigated as remarkable hydrogen evolution reaction (HER) electrocatalysts but few used as oxygen evolution reaction (OER) electrocatalysts. Herein, a Co doped Ni3C/Ni uniformly dispersed in a graphitic carbon matrix was prepared by pyrolysis of a metal organic framework (Co/Ni-MOF) under a flow of Ar/H-2 at 350 degrees C, and Ni3C/Ni@C was also prepared for comparison. The various characterization techniques confirmed the successful preparation of the heteroatom doped TMCs-based catalysts by pyrolysis of MOFs. Co doped Ni3C/Ni@C exhibited superior electrocatalytic properties for OER. For example, Co-Ni3C/Ni@C depicts a lower overpotential and smaller Tafel slope than Ni3C/Ni@C and IrO2 during the OER in 1 M KOH solution, additionally, it shows a higher active surface area than Ni3C/Ni@C. The outstanding electrocatalytic performance of Co-doped Ni3C/Ni@C in the OER was mainly ascribed to the synergistic effect of the Co and Ni3C/Ni active sites. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.