Electroactive Site Engineering in Nickel Boride-Phosphide for Enhanced Large-Scale Hydrogen Production

Abstract

Morphological optimization combined with electronic modulation provides a powerful approach for designing high-performance electrocatalysts for hydrogen evolution. In this study, the successive ionic layer adsorption and reaction (SILAR) technique was employed to prepare nickel boride phosphide (Ni-B-P) catalysts for the hydrogen evolution reaction (HER). By tuning the phosphorus-to-boron (P/B) precursor molar ratio during SILAR, the particle size, electron redistribution among elements, and the electronic environment surrounding the nickel active sites were effectively controlled. Among the prepared electrocatalysts, the NiBP2 electrode (P/B = 0.66) demonstrated exceptional HER activity, achieving an overpotential of 134 mV at 10 mA cm−2 and a Tafel slope of 93 mV dec-1 in alkaline solution. X-ray photoelectron spectroscopy (XPS) confirmed that the P/B precursor molar ratio influences electron density around Ni⁰, underscoring its role as a catalytically active site. The improved electron density of nickel, moderate growth of spherical nanoparticles, and high porosity collectively enhanced hydrogen evolution performance. Interestingly, the NiBP2 electrode delivered a hydrogen production rate of 772 mL h−1 in a prototype water electrolyser and maintained stable operation for up to 100 h, highlighting its promise as an efficient electrocatalyst for commercial hydrogen production. © 2026 Elsevier Ltd.