Centre for Translational Atomaterials, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia.
Institute of Clean Energy Chemistry, Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials, College of Chemistry, Liaoning University, 66 Chongshan Middle Road, Shenyang, 110036, China.
Small. 2022 Mar;18(11):e2105830. doi: 10.1002/smll.202105830. Epub 2021 Dec 8.
Electrocatalytic water splitting is regarded as the most effective pathway to generate green energy-hydrogen-which is considered as one of the most promising clean energy solutions to the world's energy crisis and climate change mitigation. Although electrocatalytic water splitting has been proposed for decades, large-scale industrial hydrogen production is hindered by high electricity cost, capital investment, and electrolysis media. Harsh conditions (strong acid/alkaline) are widely used in electrocatalytic mechanism studies, and excellent catalytic activities and efficiencies have been achieved. However, the practical application of electrocatalytic water splitting in harsh conditions encounters several obstacles, such as corrosion issues, catalyst stability, and membrane technical difficulties. Thus, the research on water splitting in mild conditions (neutral/near neutral), even in natural seawater, has aroused increasing attention. However, the mechanism in mild conditions or natural seawater is not clear. Herein, different conditions in electrocatalytic water splitting are reviewed and the effects and proposed mechanisms in the three conditions are summarized. Then, a comparison of the reaction process and the effects of the ions in different electrolytes are presented. Finally, the challenges and opportunities associated with direct electrocatalytic natural seawater splitting and the perspective are presented to promote the progress of hydrogen production by water splitting.
电催化水分解被认为是生成绿色能源-氢气的最有效途径，氢气被认为是解决世界能源危机和减缓气候变化的最有前途的清洁能源之一。尽管电催化水分解已经提出了几十年，但大规模工业制氢受到高电价、资本投资和电解介质的阻碍。在电催化机制研究中广泛采用了苛刻的条件（强酸/强碱），并取得了优异的催化活性和效率。然而，在苛刻条件下（如强酸/强碱）实际应用电催化水分解会遇到一些障碍，如腐蚀问题、催化剂稳定性和膜技术难题。因此，在温和条件（中性/近中性，甚至在天然海水中）下的水分解研究引起了越来越多的关注。然而，温和条件或天然海水中的机制尚不清楚。本文综述了电催化水分解的不同条件，并总结了这三种条件的影响和提出的机制。然后，对不同电解质中反应过程和离子的影响进行了比较。最后，提出了直接电催化天然海水分解所面临的挑战和机遇，并展望了促进水分解制氢的进展。
