In-situ surface decoration of RuO2 nanoparticles by laser ablation for improved oxygen evolution reaction activity in both acid and alkali solutions

Abstract Improving the OER activity of noble metal-based materials is of profound importance to minimize the usage of noble metals and lower the cost. Here, we report considerable improvement on the catalytic activity of RuO2 particles for OER in both alkali and acid environments. The RuO2 nanoparticles were treated with a method of pulse laser ablation. Numerous Ru and RuO2 clusters were generated at the surface of RuO2 nanoparticles after the laser ablation, forming a lychee-shaped morphology. The larger pulse energy RuO2 nanoparticles are treated with, the better the OER activity can be. DFT calculations shows that the surface tension induced by the lychee-shaped morphology benefits the OER performance. Our best sample gives an overpotential of 172 mV (at 10 mA cm-2) and a Tafel slope of 53.5 mV dec-1 in KOH, while an overpotential of 219 mV and a Tafel slope of 44.9 mV dec-1 in H2SO4, which are of top-class results. This work may inspire a new way to develop high-performance electrocatalysts for OER.