Large-scale production of a low-cost molybdenum dioxide–phosphide seamless electrode for high-current-density hydrogen evolution

Abstract

Herein, we report the large-scale production of a molybdenum oxide–phosphide (MoO₂–MoP) seamless electrode (SE) that is vertically grown on cheap industrial-grade molybdenum substrates (e.g. molybdenum plate, molybdenum mesh, or molybdenum wire) using a facile solid-state synthesis method, which is suitable for various devices under complex application conditions. These features give the seamless electrode a mechanically robust and excellent electrical contact between the MoO₂–MoP catalyst and Mo substrate, leading to high HER activity and excellent durability, together with a low overpotential of 362 mV to achieve a current density of 800 mA cm⁻². Surprisingly, the MoO₂–MoP mesh electrode affords a current density of 1000 mA cm⁻² at 293 mV in 1.0 M KOH solution, while it needs an overpotential of only 215 mV to achieve the same current density in 5.0 M KOH solution, which is suitable for practical alkaline hydrogen production. This work throws light on the rational design of the large-scale production of electrocatalysts for efficient hydrogen production at the industrial level.