Beyond freshwater: A critical review of next-gen strategies for scalable and efficient seawater splitting to green hydrogen fuel

This review analyzes the advancements and challenges associated with electrocatalytic seawater splitting for green hydrogen production, underscoring hydrogen's promise as a clean energy carrier. It explores various hydrogen production methods, focusing on water electrolysis as a viable alternative to fossil fuels, particularly leveraging the abundance of seawater. The review highlights critical issues such as freshwater scarcity and the corrosive nature of seawater, which complicate the electrolysis process, and key challenges include the struggle between the oxygen evolution reaction (OER) and chlorine evolution reaction (CER), which can generate toxic byproducts and degrade electrocatalysts. This review provides a comprehensive comparison of various strategies involving electrochemical parameters to enhance electrochemical performance in seawater splitting. The review also discusses advancements in the synthesis of electrocatalysts, emphasizing the significance of morphological engineering and the synergistic effects of multi-component materials. It notes that the structural complexity of the electrolyte environment and contaminations on electrode surfaces can significantly disturb catalyst active sites, necessitating controlled synthesis strategies. Despite progress, a comprehensive understanding of growth mechanisms is still lacking, which limits the practical application of various morphologies. The potential of alloys and heteroatom doping to enhance catalytic activity and the challenges of optimizing these approaches are highlighted. Moreover, the review suggests interfacial engineering to mitigate chlorine corrosion and improve catalyst stability. Various strategies, including defect engineering and protective layers, are proposed to enhance electrocatalytic activity. Ultimately, the review emphasizes the promise of developing multifunctional electrocatalytic materials for efficient hydrogen production from seawater, which will advance renewable energy technologies.