Activating ruthenium dioxide via compressive strain achieving efficient multifunctional electrocatalysis for Zn-air batteries and overall water splitting

Surface strain engineering is a promising strategy to design various electrocatalysts for sustainable energy storage and conversion.However,achieving the multifunctional activity of the catalyst via the adjustment of strain engineering remains a major challenge.Herein,an excellent trifunctional electrocatalyst(Ru/RuO_(2)@NCS)is prepared by anchoring lattice mismatch strained core/shell Ru/RuO_(2)nanocrystals on nitrogen-doped carbon nanosheets.Core/shell Ru/RuO_(2)nanocrystals with~5 atomic layers of RuO_(2)shells eliminate the ligand effect and produce~2%of the surface compressive strain,which can boost the trifunctional activity(oxygen evolution reaction[OER],oxygen reduction reaction[ORR],and hydrogen evolution reaction[HER])of the catalyst.When equipped in rechargeable Zn-air batteries,the Ru/RuO_(2)@NCS endows them with high power(137.1 mW cm^(2))and energy(714.9 Wh kg_(Zn)^(-1))density and excellent cycle stability.Moreover,the as-fabricated Zn-air batteries can drive a water splitting electrolyzer assembled with Ru/RuO_(2)@NCS and achieve a current density of 10 mA cm^(2)only requires a low potential~1.51 V.Density functional theory calculations reveal that the compressive strained RuO_(2)could reduce the reaction barrier and improve the binding of rate-determining intermediates(*OH,*O,*OOH,and*H),leading to the enhanced catalytic activity and stability.This work can provide a novel avenue for the rational design of multifunctional catalysts in future clean energy fields.