Engineering core–shell nanocatalysts for boosting electrocatalytic water electrolysis

Electrocatalytic water electrolysis represents a pivotal technology for sustainable hydrogen production, whose efficiency and large-scale application depend critically on the development of highly active, stable, and cost-efficient catalysts. Core-shell nanocatalysts, characterized by their distinctive architectures, have shown remarkable promise in enhancing water splitting performance. To offer a systematic overview of recent progress, this review comprehensively summarizes advances in the rational design and engineering of core–shell nanocatalysts for efficient electrocatalytic water splitting. We highlight the unique structural and electronic advantages of core–shell configurations, such as tunable electronic interaction between components, strain effects, tailored active site exposure, protective shell layers for improved stability, and controllable local reaction microenvironments. Furthermore, we elucidate the fundamental mechanisms behind the enhanced catalytic performance, including interfacial electron redistribution, d -band center modulation, and synergistic core–shell interactions. Finally, we outline existing challenges and future research directions, covering scalable synthesis, operational durability under industrial conditions, and the integration of core–shell catalysts into practical electrolyzer systems. This review aims to provide valuable insights and guidelines for the design of advanced core–shell electrocatalysts to accelerate the industrialization of green hydrogen production.