In-situ engineering of 3D amorphous/crystalline NiFeP/NiMoP/NF composite for improved hydrogen evolution

Abstract

Developing High-performance, low-cost, and non-noble-metal hydrogen evolution reaction (HER) electrocatalysts are one of the particularly significant elements to triumph over the slow kinetics of water dissociation. However, utilizing non-noble metal electrocatalysts at large-scale applications remains a significant challenge. This work informs the fabrication of porous amorphous NiFeP nanostructures on crystalline NiMoP/NF nanoflakes morphology via straightforward two-step electrodeposition and hydrothermal processes as a binder-free 3D hetero-structured composite catalyst for reliable HER. Based on experimental characterizations and density functional theory (DFT) calculations, the optimized NiFeP@NiMoP@NF electrocatalyst exhibits a favorable amorphous/crystalline morphology and an intrinsic metallic phase. This structure facilitates efficient charge transport and exposes abundant active sites with strong electronic interactions between NiFeP and NiMoP, significantly optimizing the adsorption and desorption energy of H₂O and thus leading to easy adsorption of H and OH⁻ on NiFeP@NiMoP and promoting the bubble release, finally improving electrocatalytic HER performance in alkaline media (only need an overpotential of 40 mV to conduct a current density of 10 mA cm⁻²). The rational and affordable developing technique in this study not only implies the importance of interface engineering in catalyst construction but also opens a new route for synthesizing high-efficiency Ni-based electrocatalysts for a variety of water electrolysis applications.