Breaking Activity-Durability Inverse Relationship via Electrode Engineering by Utilizing β-MnO2/RuO2 Heterostructures for Efficient Seawater Electrolysis

Abstract

Significant efforts are underway to enhance the efficiency of water electrolysis for sustainable hydrogen production. Approaches that were explored are the design of an efficient anode, engineering of electrolytes, and application of diffusion protective layer over the catalyst to protect it from corrosive reactions. Here we are exploring the engineering of electrode fabrication to enhance the efficacy of anode catalysts by ensuring that the materials are carefully selected. β-MnO₂ has been used to develop a cost-effective method for electrode fabrication that establish a Schottky junction at heterostructure interface. This method transforms commercial RuO₂, which is considered to be less active and stable, highly selective for chlorine oxidative reactions, into a highly active, stable, and OER-selective in alkaline medium and surrogate seawater. With the help of thorough electrochemical techniques, we found that this engineering significantly improves the effective electrochemical surface area, and higher kinetics and conversion per unit site, profoundly affecting the charge transfer mechanism and optimizing the adsorption of OER intermediates, resulting in much-increased mass activity. It is observed that the selectivity of the OER was enhanced due to the Lewis acid repercussions of β-MnO₂.