Modulation for RuO₂/TiO₂ via Simple Synthesis to Enhance the Acidic Oxygen Evolution Reaction

Abstract

Green hydrogen production with water splitting devices, especially a proton exchange membrane water electrolyzer (PEMWE), has received extensive attention. However, the sluggish kinetics of the oxygen evolution reaction (OER) still hinders its large-scale commercial application. Designing high-performance and low-cost electrocatalysts to drive the OER reaction remains a tough challenge. The active nanoparticles incorporating with metal oxide support is considered a promising strategy to improve durability and activity in acidic electrolytes. However, efficient synthesis methods without support premodification are rarely investigated. Herein, a simple but effective hydrothermal method accompanying the gradient annealing temperature was used to synthesize commercial TiO2 supported RuO2. The representative RuO2/TiO2-T250 required a low overpotential of 239 mV (@10 mA cm–2) with a Tafel slope value of 41.49 mV dec–1 and stability of over 20 h, far exceeding the performance of commercial RuO2. T250 exhibited a crystalline but hydrated microstructure, and the existing support-metal oxide interaction redistributed the electrons around Ru and Ti, which both gave rise to the activity of the electrocatalyst as well as hindered the Ru dissolution, thereby enhancing the OER performance. The synthesis strategy creates an important platform for designing more robust electrocatalysts for PEMWE application.