Two-dimensional materials for high-current-density seawater electrolysis

Abstract

Seawater electrolysis is a promising strategy for sustainable hydrogen production, using abundant water resources, while reducing freshwater depletion. However, achieving stable and efficient operation at industrially relevant current densities remains challenging, due to competition from the chlorine evolution reaction (CER), catalyst degradation, and mass transport limitations. Two-dimensional (2D) materials offer tunable electronic structures, high surface areas, and unique charge transport properties, yet their stability and catalytic mechanisms under high current densities remain insufficiently understood. While existing studies have focused on compositional tuning and surface modifications, a systematic understanding of how 2D architectures influence reaction kinetics, charge transfer, and long-term durability is still lacking. This review critically analyzes the role of 2D materials in high-current-density seawater electrolysis, focusing on structural and electronic properties, catalytic mechanisms, and stability. Unlike previous reviews that broadly discuss 2D materials for water electrolysis, this work highlights challenges and opportunities under industrial conditions. Materials are classified into metal oxides, hydroxides, sulfides, phosphides, carbides, nitrides, and other emerging compounds, with emphasis on their catalytic performance and electrochemical durability, while identifying key factors that optimize performance. These insights are essential for developing efficient, durable 2D catalysts for seawater electrolysis, contributing to sustainable hydrogen production and green chemistry.