Co1-xS embedded in porous carbon derived from metal organic framework as a highly efficient electrocatalyst for oxygen evolution reaction

Developing active, robust, and cost-efficient electrocatalysts is critical for oxygen evolution reaction (OER). Here, a novel composite catalyst of Co_1-xS embedded in porous dodecahedron carbon hybrid was synthesized by a two-step conversion protocol of a cobalt-based metal-organic framework (ZIF-67). The porous dodecahedron Co_1-xS@C composite catalyst was prepared by direct oxidation of ZIF-67 followed by sulfurization reaction. The Co_1-xS@C composite exhibit superior OER performance, including a low overpotential of 260 mV for 10 mA/cm², a small Tafel slope of ～85 mV/dec, outstanding stability over 80 h and almost 100% Faradaic efficiency. The various material characterizations indicate that the excellent activity and strong stability of Co_1-xS@C might be attributed to good conductivity of Co_1-xS, mesoporous nanostructure, and synergistic effect of Co_1-xS encapsulated within porous carbon. This work provides a novel strategy for designing and synthesizing advanced composite electrocatalysts