Plasmon enhanced oxygen evolution reaction on Au decorated Ni(OH)2 nanostructures: The role of alkaline cations solvation

Water electrolysis is widely acknowledged to be kinetically hindered by the oxygen evolution reaction (OER), which involves multiple electron transfer steps. A critical yet often overlooked factor ruling the OER rate is the intricate interplay between alkaline cations of electrolyte, reaction intermediates, and the electrocatalyst surface. This study investigates the impact of plasmonic excitation on the OER using hexagonal hybrid Ni(OH)(2)-Au nanoplates in different alkaline electrolytes. While CsOH electrolyte exhibited the highest overall OER electroactivity, LiOH presented a remarkable enhancement under plasmonic excitation. Furthermore, FTIR-RAS and calculations analysis revealed that plasmonic relaxation mechanisms accelerate the Li+ environment modification process, mimicking the electrostatic configuration of Cs+, which facilitates a stabilized interaction between the active site (Ni3+) and OER intermediates, promoting rapid O-O bond formation. Our findings suggest that manipulating the cation's vicinity through plasmonic heating is a promising strategy for enhancing OER efficiency.