Designing electrocatalysts for seawater splitting: surface/interface engineering toward enhanced electrocatalytic performance

Abstract

As an ideal large-scale energy conversion/storage technology, electrochemical hydrogen production has great potential as a means of smoothing out the volatility of renewable sources. Electrocatalytic seawater splitting utilizes abundant natural seawater to replace purified water; this has considerable economic and environmental benefits, and will greatly expand the applications scope of water splitting. However, complex compositions existing in natural seawater hinder efficient H2 electrosynthesis, especially chlorides that corrode the catalysts. Advanced surface and interface engineering has been demonstrated to be critical for the construction of efficient and stable electrodes for seawater electrolysis. In the review, we firstly introduce the fundamentals of direct seawater splitting and provide a comprehensive analysis of the basic reactions on electrodes from the perspective of thermodynamics and kinetics. Subsequently, rational design strategies for HER and OER electrocatalysts applied to seawater or chloride-containing electrolytes in terms of catalytic activity, selectivity and corrosion resistance are discussed comprehensively. Moreover, the applications of surface/interface engineering in the performance tuning of seawater electrolytic electrocatalysts are presented. Finally, the current state of the research is presented, along with potential areas for further innovation.