Amorphous CoFeP/NC hybrids as highly efficient electrocatalysts for water oxidation

The rational design and regulate structure and composition are pivotal for the development of highly efficient oxygen evolution reaction (OER) catalysts for water splitting. In this study, amorphous CoFeP/NC hybrid electrocatalyst has been synthesized by a simple and effective phosphorization of a CoFe-based coordination polymer under N-2 atmosphere. The synergistic effects between the CoFeP and N-doped carbon has led to high electronic conductivity attributed to the optimal Fe contents with N-doped carbon and enlarged electrocatalytic active surface area aroused by the nanostructure of CoFeP/NC, as well as the surface structural evolution of oxyhydroxide/phosphate during OER process. The resulting Co0.35Fe0.17P0.48/NC electrocatalyst can attain a current density of 10 mA/cm(2) at an overpotential of 275 mV with a Tafel slope of 31 mV/dec on glassy carbon electrode and 228 mV on Ni foam electrode in 1 M KOH solution, long-term OER stability of this Co0.35Fe0.17P0.48/NC under the applied potential of 1.53 V vs. RHE demonstrates no obvious decline in current densities of 110 mA/cm(2) within 17 h, which outperforms those of the contrast electrocatalysts in this work and also comparable to that of many of the reported electrocatalysts in the literatures. This Co0.35Fe0.17P0.48/NC electrocatalyst highlights the rational modulation of optimal composition and electronic structure with homogeneous incorporation of the foreign metal-doped and N-doped carbon for the synthesis of highly efficient electrocatalysts toward to the water oxidation reactions. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.