Self-Disproportionation-Induced H-Adsorption/Desorption Zones in Amorphous Nickel Boride Cocatalyst for Efficient...

Hydrogen spillover is a well-established strategy for enhancing hydrogen evolution kinetics; however, in conventional binary-component catalysts, its efficiency is often limited by long diffusion distances and significant interfacial resistance. Herein, we developed an efficient intraparticle hydrogen spillover pathway in isolated amorphous nickel boride (a-NiB) cocatalysts through an amorphization-induced self-disproportionation strategy, which significantly enhances H₂-evolution kinetics. Combined experimental and theoretical results demonstrate that amorphization induces uneven compression and stretching of Ni-B bonds, leading to the electronic density disproportionation of nickel active sites. This effect creates spatially separated electron-deficient and electron-rich microzones within each a-NiB nanoparticle, promoting efficient hydrogen adsorption and desorption, respectively, and thereby enabling facile intraparticle hydrogen spillover within the a-NiB cocatalyst. When coupled with CdS photocatalysts, the a-NiB cocatalyst enables vigorous visible-light-driven H₂ evolution with macroscopic bubble formation and achieves a quantum efficiency of 53%. This work redefines catalyst design in amorphous materials and opens new frontiers for energy synthesis technologies.