Electronic structure exquisite restructuring of cobalt phosphide via rationally controlling iron induction for water splitting at industrial condition

Abstract

The rational design of high-efficiency bifunctional electrocatalysts for industrial water splitting and the understanding of intricate catalytic mechanisms remain a huge challenge. Herein, the ultrathin iron-dopedcobalt phosphide (Fe-CoP) nanosheets are prepared by hydrothermal, oxidation and phosphating path. The incorporation of Fe in CoP matrix greatly ameliorates the electronic structure and charge transfer ability of targeted product. In addition, the Fe-CoP substance with an uniquely ultrathin nanosheet architecture can also increase more active sites and promote electron transfer, leading to improved oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) activities. As anticipated, the Fe-CoP catalyst displays outstanding bifunctional properties with the overpotentials of only 249 and 78.5 mV at 10 mA cm-2, and the Tafel slopes of 43.1 and 60.7 mV dec-1 for OER and HER, respectively. Simultaneously, the electrolyzer assembled with Fe-CoP as two electrodes just requires 1.37 V to reach 10 mA cm-2 for water splitting along with good stability at industrial environment (60 °C, 6.0 M KOH). The density functional theory (DFT) calculations disclose that the incorporation of Fe into CoP can efficaciously optimize the electronic structure to accelerate the adsorption and desorption of *H, and the formation of *OOH crucial intermediate, consequently yielding excellently electrocatalytic performance. Our findings provide a facile and feasible approach to design highly active catalysts for factually electrolytic water application.