RuSe2 and CoSe2 Nanoparticles Incorporated Nitrogen-Doped Carbon as Efficient Trifunctional Electrocatalyst for Zinc-Air Batteries and Water Splitting.

ABSTRACT

The development of affordable, highly active, and stable trifunctional electrocatalysts is imperative for sustainable energy applications such as overall water splitting and rechargeable Zn-air battery. Herein, we report a composite electrocatalyst with RuSe2 and CoSe2 hybrid nanoparticles embedded in nitrogen-doped carbon (RuSe2CoSe2/NC) synthesized through a carbonization-adsorption-selenylation strategy. This electrocatalyst is a trifunctional electrocatalyst with excellent hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) activities. An in-depth study of the effect of Se on the electrocatalytic process was conducted. Notably, the incorporation of Se moderately adjusted electronic structure of Ru and Co, enhancing all three types of catalytic performance (HER, η10 = 31 mV; OER, η10 = 248 mV; ORR, E1/2 = 0.834 V) under alkaline condition with accelerated kinetics and improved stability. Density functional theory (DFT) calculation reveals that the (210) crystal facet of RuSe2 is the dominant HER active site as it exhibited the lowest ΔGH* value. The in situ Raman spectra unravel the evolution process of the local electronic environment of Co-Se and Ru-Se bonds, which synergistically promotes the formation of CoOOH as the active intermediate during the OER. The superior catalytic efficiency and remarkable durability of RuSe2CoSe2/NC as an electrode for water splitting and zinc-air battery devices demonstrate its great potential for energy storage and conversion devices.