ZIF-67-derived Co, Ni and S co-doped N-enriched porous carbon polyhedron as an efficient electrocatalyst for oxygen evolution reaction (OER)

Rational fabrication of highly efficient and non-precious metal electrocatalysts for oxygen evolution reaction (OER) are of great importance for renewable energy exploitation to solving the energy crisis and environmental problems. In this paper, we report a novel hybrid nanostructure with Co, Ni and S co-doped N-enriched porous carbon polyhedron (CoNixSy/NCP) via a absorption-pyrolysis-sulfuration strategy derived from zeolitic imidazolate framework-67 (ZIF-67) and explored its electrocatalytic performance for OER. During the synthesis process, Ni2+ is abosrbed within the pores or surface of ZIF-67 and Ni/ZIF-67 can be transformed into the Co and Ni co-doped porous carbon frameworks when it is sulfurazed at 800 °C. NiS2 and NiCo2S4 nanoparticles formed at high temperature are homogeneously dispersed in porous carbon and can activate its electrocatalytic performance. The porous carbon can enhance the electrochemical surface area and charge transfer efficiency. Benefiting from the synergistic effects between highly active NiS2, NiCo2S4, and porous carbon, CoNixSy/NCP electrocatalyst exhibits excellent electrocatalytic performance. The results show that CoNixSy/NCP also exhibits a potential as low as 1.51 V to achieve 10 mA/cm2 current density and extremely stability towards OER. The good electrocatalytic activity of CoNixSy/NCP further suggest its great potential as an efficient eletctocatalyst for sustainable energy applications.