Self-Ordered Anodic Porous Oxide Layers as a High Performance Electrocatalyst for Water Oxidation

During electrochemical water splitting, the oxygen evolution reaction (OER) is one of the significant steps with the maximum incredible limiting effects on efficiency, primarily due to the high overpotentials associated with the materials utilized on the anode side. Herein, we present a simple two-step surface modification performed on a general-purpose austenitic stainless steel (SS 304) composed of the earth-abundant metals Fe, Cr, and Ni. The modification is highly likely of thin porous oxide layers that significantly improve water oxidation performance in a strongly alkaline medium. Furthermore, the oxide layer formed by the two-step surface treatment of stainless steel provides a stable outer layer. It is inert to long-term operations in an alkaline environment, demonstrated by consistent OER performance after 2000 CV cycles and 24 h of chronopotentiometric testing. This electrolyzer, especially surface-treated stainless steel, could be a game-changer in creating efficient and affordable catalysts for alkaline water electrolyzer systems. It offers cost-effective solutions with comparative electrocatalytic capabilities. Its production can be scaled up for widespread use.