Rational Design of Multiple Heterostructures with Synergistic Effect for Efficient and Stable Hydrogen Evolution Toward Industrial Alkaline Water Splitting

Electrocatalytic hydrogen evolution reaction (HER) via alkaline water splitting holds great promise for industrial clean hydrogen production but is frustrated by limited catalytic activity and inferior stability under high current density. Elaborate manipulating of heterostructure on robust catalytic electrodes is essential but challenging for accelerating HER kinetics with high durability. Herein, a robust nickel mesh electrode, offering high mechanical stability, is directly engineered with catalytic layers of multiple heterostructures (r-Mn-Ni/CoP) via facile one-pot electrodeposition followed by surface reconstruction strategy. The abundant heterostructures composed of crystalline CoP, NiP, amorphous region, and additional Mn doping considerably manipulate the electronic structure with optimized charge transfer; while the in situ surface-reconstructed hydrophilic nanoflakes enable the rapid wetting of active sites to the electrolyte. Consequently, the r-Mn-Ni/CoP requires only 134 mV overpotential at the current density of 100 mA cm-2, superior to monophasic and undoped samples, and the majority of reported HER catalysts. Remarkably, an electrolyzer with r-Mn-Ni/CoP on a nickel mesh cathode demonstrates extraordinary activity with a voltage of 1.734 V at 300 mA cm-2 and stable operation of 800 h. The finding provides a feasible strategy for the fabrication of nonprecious-metal-based HER electrocatalysts with high activity and stability toward industrial water electrolysis. Through facileelectrodeposition and surface electrochemical reconstruction strategy, r-Mn-Ni/CoP catalysts are loaded onto nickel mesh substrates with higher mechanical strength than nickel foam. Multiple heterostructures with additional Mn doping and super-hydrophilic nanoflakes synergistically result in high alkaline HER activity and stable industrial application in electrolyzers, especially at large current density. image