Advances in RuO2-based heterostructures as high-performance electrocatalysts toward electrochemical water splitting.

Abstract

The global pursuit of carbon neutrality has deepened people's understanding of green hydrogen, thereby accelerating the growing demand for this clean energy carrier. Among the existing production strategies, water electrolysis remains the only commercially viable way to produce zero-carbon-emission green hydrogen. Ru-based materials, especially ruthenium oxide (RuO2), exhibit great potential in the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) of water electrolysis due to their high intrinsic activity and comparative cost advantages. However, RuO2 is prone to oxidative dissolution during water electrolysis, leading to structural instability and activity decay. This stability issue has become a key bottleneck restricting its practical application. Constructing heterojunction catalysts provides a feasible path to surpass the performance limitations of single-component materials. By forming interfacial coupling between RuO2 and functional materials, including metals, metal oxides, and nonmetallic compounds, the adsorption energy of reaction intermediates is optimized, thereby enhancing catalytic activity while inhibiting the dissolution of active components and improving structural stability. This review provides a systematic overview of recent advances in RuO2-based heterojunction electrocatalysts for water electrolysis across both acidic and alkaline environments. This review specifically elucidates the design and synthesis strategies and discusses the related mechanisms for performance improvement. Furthermore, this review analyzes the remaining challenges in the synergistic tuning of the activity and stability of RuO2-based heterojunction catalysts and outlines prospective research directions to address these gaps.