Heterogeneous VN/MoP Nanoparticles Embedded in a Nitrogen-Doped Carbon Framework Achieve Efficient Electrocatalytic Hydrogen Evolution
Qingqing Liu, Liyun Cao, Koji Kajiyoshi, Dewei Chu, Yijun Liu, Yong Zhao, Jianfeng Huang, Liangliang Feng
Abstract
Amidst escalating global energy demands, the electrochemical hydrogen evolution reaction (HER) presents a sustainable pathway for clean hydrogen production. The rational design of heterostructured electrocatalysts is a promising strategy to overcome the inherent limitations of single-component catalysts for the hydrogen evolution reaction (HER). While vanadium nitride (VN) exhibits Pt-like electronic properties, insufficient electron density at V sites impedes hydrogen adsorption. Conversely, molybdenum phosphide (MoP) features a moderate Mo–P bond strength with intermediates, facilitating hydrogen desorption kinetics. Herein, we construct a VN/MoP heterointerface embedded in a nitrogen-doped carbon framework (VN/MoP@NC) via a one-step solid-phase sintering approach to synergistically modulate the electronic structures. Experimental results confirm that interfacial electron transfer from MoP to VN enriches the electron density of V sites, thereby optimizing the hydrogen adsorption free energy (Δ G H* ). The heterojunction optimizes interfacial charge distribution and adsorption energetics, enabling an overpotential of 111 mV at 10 mA cm –2 in alkaline media with 50 h of stability. Furthermore, in a practical membrane electrode assembly (MEA), it delivers a high current density of 1000 mA cm –2 at a low cell voltage of 2.18 V for alkaline water electrolysis. This work not only demonstrates the effectiveness of electronic coupling in heterostructure engineering but also validates the catalyst’s promise for realistic hydrogen production.