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

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.