In situ fabrication of 3D self-supporting cobalt phosphate-modified graphite felt electrocatalysts for oxygen evolution reaction in neutral solution

In this communication, an easy, two-step hydrothermal synthetic protocol for the preparation of hybrid cobalt phosphate/graphite felt (Co-3(PO4)(2)@GF) electrocatalyst is described, where Co-3(PO4)(2)center dot 4H(2)O is precipitated onto a 3D self-supporting graphite felt (GF). The prepared electrocatalyst, denoted hereafter as GF-Co-P, showed an onset overpotential at 370 mV for the oxygen evolution reaction (OER), which is superior to that of the standard reference material RuO2; and a Tafel slope of 133 mV dec(-1) in a pH-neutral phosphate buffer solution (PBS). In addition, it exhibited excellent catalytic stability over extended run times. We revealed that surface phosphorylation greatly enhances the exposure of active cobalt sites at catalyst surfaces, and therefore promotes the charge transfer process for OER in neutral solution. (c) 2020 Elsevier B.V. All rights reserved.