Self-supported electrocatalysts for high-current-density water/seawater electrolysis

Electrolysis of water is a cost-effective and sustainable technology for hydrogen energy production, whereas the development of low-cost and efficient electrocatalysts remains a significant challenge due to slow electrocatalytic reaction kinetics during water splitting. Self-supported electrocatalysts with controllability of morphology and structure have emerged as promising candidates due to their increased active sites, which improve the charge transportation and overall excellent performance under high current density at full pH range whether in water or seawater. This review focuses on the affection of dimensionality, morphology, surface structure, related electronic transport path, and substrate selection during the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and chloride ion electrooxidation reaction (CIER) processes on self-supported catalysts and their reaction mechanisms. Moreover, the recent advancements and practical applications of self-supported catalysts are also summarized, along with the challenges and perspectives for their designation and application in hydrogen production.