Construction of NiFeP/CoP nanosheetsanowires hierarchical array as advanced electrocatalysts for water oxidation

摘要

Cost-effective hierarchical electrocatalysts with excellent performance and high stability for water splitting play an important role in promoting social sustainable development. Herein, we report a three-dimensional (3D) trimetallic nickel-iron-cobalt phosphide with a hierarchical nanoarray structure grown in situ on carbon cloth via a combined method of two-step hydrothermal reaction and following low-temperature phosphating using a carbon cloth as a conductive substrate. The synthesized NiFeP/CoP/CC exhibits excellent oxygen evolution reaction (OER) catalytic performance, giving small overpotentials of 250 mV, 270 mV and 320 mV at current densities of 20 mA cm(-2), 50 mA cm(-2) and 200 mA cm(-2) in alkaline electrolyte, respectively, with a small Tafel slope of 51 mV dec(-1). In addition, the catalytic activity of the material remains stable for at least 50 h, and the turnover frequency (TOF) is 0.466 mol 02 s(-1) at an over potential of 300 mV. These properties of the material are comparable to those of the noble metal catalyst RuO2/CC, which may be ascribed to the hierarchical microstructure, good conductivity and desirable synergistic effect among metal ions. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.