Precisely Engineered Ultrathin Nanosheets With Amorphous Ni(OH) x ‐Encapsulated Ru Nanoclusters for Enhanced Water Splitting in Neutral Media

Abstract

Incorporating metal hydroxides and other hydrolysis promoters is an effective strategy for enhancing hydrolysis kinetics under neutral conditions. However, conventional heterostructure catalysts are limited by inefficient interfacial proton transfer, hindering the sufficient proton supply to active sites. Here, an ultrathin two‐dimensional nanosheet composite (2D‐Ru NCs@Ni(OH) x ) composed of an amorphous nickel hydroxide (Ni(OH) x ) matrix encapsulating ultrafine ruthenium nanoclusters (Ru NCs) is designed to achieve high‐performance neutral hydrogen evolution reaction (HER). This unique “core–shell” structure forms abundant Ni–O–Ru interfaces, greatly enhancing the kinetics of interfacial proton transport. Meanwhile, the synergistic effect between amorphous Ni(OH) x and Ru NCs optimizes the adsorption of reaction intermediates on each component. The resulting catalyst exhibits low overpotential of 14.7 mV and high durability of 1500 h at 10 mA cm −2 for neutral HER. Furthermore, it also shows outstanding catalytic activity in alkaline media, requiring only 9.6 mV to reach 10 mA cm −2 . This study provides valuable theoretical insights for designing high‐performance two‐dimensional ultrathin catalysts and is expected to facilitate their practical applications in water splitting and other catalytic processes.