One-Step Exsolution Strategy for the Reconstruction of the RuO2/La0.9Fe0.92Ru0.08O3 Composite for the Enhanced Oxygen Evolution Reaction

The noble metal oxide RuO2 is an efficient catalyst for the oxygen evolution reaction (OER), and its catalytic activity can be significantly improved by Ru exsolution and subsequent oxidation to RuO2 nanoparticles on the perovskite surface. Conventional methods typically require sequential H2/Ar reduction for Ru exsolution followed by oxidation, which complicates the process and introduces potential safety hazards. Herein, we propose introducing nanodiamond (ND) into La0.9Fe0.92Ru0.08O3 (LFR) gels for ambient calcination. ND facilitates Ru exsolution and oxidation to RuO2, significantly simplifying RuO2/LFR preparation. The ND-modified RuO2/LFR exhibits high OER activity, achieving an overpotential of 275 mV at 10 mA cm–2 and a Tafel slope of 48.16 mV decade–1. This Tafel slope represents a 50% reduction compared to that of pure RuO2. Furthermore, the catalyst retains 84% of its initial current density after 24 h. Our work provides insight into enhancing electrocatalytic activity by a one-step in situ exsolution of metal oxides.