Abstract
The sluggish kinetics of the hydrogen evolution reaction (HER) result in a high overpotential in alkaline solutions. A high-curvature metal oxide heterostructure can effectively boost the electrocatalytic HER by leveraging the tip-enhanced local electric field effect. Herein, Ni2P/NiMoOx nanocones were synthesised on a nickel foam (NF) substrate by etching a metal-organic framework template. The Ni2P/NiMoOx nanocones on the NF substrate served as an advanced electrocatalyst for the HER. Analysis using the finite element method indicated that the high-curvature tips of the Ni2P/NiMoOx nanocones enhanced the local electric field, resulting in a higher concentration of hydrated K+ ions (K(H2O)6+), which facilitated water dissociation and accelerated the reaction kinetics. The tip-enhanced local electric field effect accelerates the mass transfer rate, and the heterostructure promotes charge transfer to activate the active center, thereby synergically enhancing the electrocatalytic reaction. The Ni2P/NiMoOx nanocone electrocatalyst exhibited low overpotentials of 49, 137 and 274 mV at 10, 100 and 500 mA cm-2, respectively, under alkaline conditions for the HER. In addition, the electrocatalyst demonstrated excellent stability over 200 h at 300 mA cm-2. This study provides a promising approach for developing efficient electrocatalysts that facilitate the HER in alkaline solutions.
Published Version
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