A Review on Electrochemical Water Splitting Electrocatalysts for Green H2 Production: Unveiling the Fundamentals and Recent Advances

Green H₂ production via electrochemical water splitting has emerged as a pivotal solution for achieving a sustainable energy future. This Review delves into the fundamentals of water splitting, focusing on the O₂ evolution reaction (OER) and H₂ evolution reaction (HER), and focuses on the critical role of electrocatalysts in these processes. Precious metals such as paltinum and iridium remain the benchmarks for catalytic performance; however, their scarcity and high cost necessitate the development of alternative materials. Recent advances in Earth-abundant catalysts, including transition-metal oxides, carbides, nitrides, and sulfides, have shown promise in balancing activity, durability, and affordability. The integration of nanostructuring techniques and computational modeling has enabled the design of catalysts with enhanced active site exposure and electronic properties. Furthermore, the Review highlights challenges such as material degradation, high overpotentials, and gas crossover, along with potential solutions like protective coatings, bifunctional catalysts, and advanced electrolyzer designs. Future prospects emphasize the role of artificial intelligence, hybrid systems, and sustainable manufacturing in accelerating progress. This comprehensive review underscores the significance of bridging fundamental research with technological innovations to scale up green hydrogen production, addressing energy demands while mitigating environmental impacts.