Advanced materials and interface engineering for electrocatalytic water splitting: a review of mechanisms, catalysts, and future directions

Abstract

Abstract Hydrogen has been declared the fuel of the future, offering zero carbon emission, superior energy density, higher conversion efficiency, and environmental friendliness. Electrocatalytic water splitting has garnered significant interest as it can provide renewable, safe, and high-purity hydrogen. Despite progress, the precise mechanisms governing the Hydrogen Evolution Reaction (HER) remain actively debated, with prevailing pathways such as Volmer-Heyrovsky and Volmer-Tafel serving as benchmarks for evaluating electrocatalyst performance. Meanwhile, electrocatalytic water splitting faces multidimensional challenges involving the design of efficient and high-performance electrocatalysts, understanding of reaction mechanisms, and translation of these advances into industrial-scale applications. This review delves into the mechanisms underlying electrocatalytic water splitting, with particular emphasis on HER and Oxygen Evolution Reaction (OER) pathways. We critically examine the potential of noble metals, alloys, transition metal compounds, and hybrid materials as promising electrocatalysts, while evaluating the role of defects, impurities, and lattice oxygen participation in modulating catalytic activity. The lattice oxygen oxidation mechanism (LOM) is discussed as a pathway that enhances OER activity by circumventing traditional scaling limitations, yet introduces thermodynamic instability and a critical trade-off between activity enhancement and catalyst durability that must be carefully managed. A rigorous evaluation of electrocatalytic efficiency requires careful consideration of parameters including exchange current density, Tafel slope, overpotential, polarization curves, turnover frequency, and stability metrics. We analyze key optimization strategies including alloying, morphology engineering, interface construction, defect engineering, strain engineering, and heteroatom doping that have emerged as powerful tools for enhancing catalytic performance. Particular attention is given to the translation of laboratory discoveries to industrial applications, where challenges in current density, durability, scalability, and seawater electrolysis complications must be addressed. The review concludes by identifying actionable research priorities, including standardized testing protocols, advanced operando characterization, scalable synthesis methods, and integration of machine learning with computational modeling to accelerate catalyst discovery. We anticipate that these integrated approaches will enable the development of highly active, stable, and cost-effective electrocatalysts, ultimately contributing to large-scale green hydrogen production and a sustainable energy future.

The authors' abstract, as published at the source. Materials for Renewable and Sustainable Energy, 2026 · DOI ↗