Fluorine-doping-assisted vacancy engineering for efficient electrocatalyst toward hydrogen production

Abstract

The rational design of an efficient and stable electrocatalyst utilizing defects plays a crucial role in promoting hydrogen production from electrolytic water to tackle the energy crisis. In this work, we report the controllable synthesis of fluoride-anion-doped Co₂P nanoarrays on three-dimensional nickel foam as the electrocatalyst via a simple one-step electrodeposition method. Theoretical calculations confirm that the dual defects of F-anion doping and P vacancy in Co₂P can not only expose more active sites but also optimize the electronic structure of active sites. In particular, the optimal F-Co₂P/NF catalytic electrode demonstrates excellent alkaline hydrogen evolution performance with an overpotential of 46 and 117.8 mV at a current density of −10 and −100 mA cm⁻², respectively. Moreover, in a simulated industrial environment, the commercial current density of 1000 mA cm⁻² can be provided by the electrolyzer with catalytic F-Co₂P/NF electrode as the cathode as well as anode, at a cell voltage of 2.13 V, revealing the promising potential of large-scale hydrogen production. The electrocatalyst doped by the anion via electrodeposition opens up a new idea for the rational design and preparation of highly efficient and stable nonnoble-metal-based electrode materials, which is of great significance for the practical applications of electrolyzed water.