Influence of Low Magnetic Field on Hydrogen Evolution Reaction Performance of NiCoP Nanorods.

Abstract

Developing non-precious, high-efficiency, and durable electrocatalysts for H2 evolution in acidic media is highly desirable. Extensive research has focused on improving electrocatalyst activity through techniques like defect engineering, composite formation, and doping. Here, we report NiCoP nanorods' electrocatalytic activity enhancement by applying an external magnetic field. The nanorods were synthesized via a simple hydrothermal method. When coated onto carbon paper, the NiCoP nanorods exhibited an overpotential of 100 mV at 10 mA cm-2. However, under a low magnetic field of 2000 G, the overpotential reduced to 62 mV at 10 mA cm-2 in 0.5 M H2SO4, demonstrating that the external magnetic field positively affects the kinetic process of the NiCoP nanostructure. The improved mass transport through Lorentz force and the uniform alignment of magnetic moments of the material in the presence of magnetic field serve for the purpose of enhanced HER activity. Our density functional theory-based calculations support this scenario that the spin alignment can boost HER activity. These results suggest an alternative strategy for further improving the HER properties of electrocatalysts by utilizing an external magnetic field.