Customizing Bonding Affinity with Multi-Intermediates via Interfacial Electron Capture to Boost Hydrogen Evolution in Alkaline Water Electrolysis

Abstract

Developing efficient and earth-abundant alkaline HER electrocatalysts is pivotal for sustainable energy, but co-regulating its intricate multi-step process, encompassing water dissociation, OH- desorption, and hydrogen generation, is still a great challenge. Herein, we tackle these obstacles by fabricating a vertically integrated electrode featuring a nanosheet array with prominent dual-nitride metallic heterostructures characterized by impeccable lattice matching and excellent conductivity, functioning as a multi-purpose catalyst to fine-tune the bonding affinity with alkaline HER intermediates. Detailed structural characterization and theoretical calculation elucidate that charge redistribution at the heterointerface creates electron-accumulating W-W sites, which reduces the O p-W d and H s-W d interactions vs. single nitride, thereby enhancing OH- transfer and H2 release. As anticipated, the resulting WN-NiN/CFP catalyst demonstrates a gratifying low overpotential of 36.8 mV at 10 mA/cm² for alkaline HER, while concurrently maintaining operational stability for 1300 h at 100 mA/cm² for overall water splitting. This work presents an effective approach to meticulously optimize multiple site-intermediate interactions in alkaline HER, laying the foundation for efficient energy conversion.