Transition metal-based electrocatalysts for efficient seawater splitting: Recent advances and performance evaluation

In response to the increasing demand for clean and sustainable energy, hydrogen has emerged as a vital fuel for the transition to a low-carbon future. Seawater splitting presents a promising method for hydrogen production, offering an abundant and renewable alternative to freshwater-based electrolysis. However, the high salinity, presence of chloride ions, and other impurities in seawater pose significant challenges, including catalyst degradation, reduced efficiency, and competing chlorine evolution reactions (CER). Transition metal-based electrocatalysts, such as oxides, (oxy)hydroxides, nitrides, carbides, and chalcogenides, have garnered considerable attention owing to their partially filled d-orbitals, multiple oxidation states, and excellent conductivity, rendering them suitable for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Recent advancements in structural engineering, surface modification, and doping strategies have markedly enhanced the catalytic activity, selectivity, and long-term durability of these materials under harsh seawater conditions. This review outlines the fundamental principles of seawater electrolysis, summarizes the latest developments in transition metal-based electrocatalysts, and highlights recent advancements in seawater electrolysis technologies. • Seawater splitting is an efficient method for the production of sustainable hydrogen. • Transition metal-based electrocatalysts are used to enhance performance. • AWE, PEMWE, and AEMWE technologies are discussed. • Challenges and future prospects of seawater electrolysis are reviewed.