(Invited) Preparation of Core@Carbon-Shell Nanostructures and Their Applications as Bifunctional Electrocatalysts for Electrochemical Water Splitting

Abstract

A series of core@carbon-shell nanostructures with size of ~5 nm are prepared, in which RuM-based nanoparticle is encapsulated with an ultra-thin carbon shell (see Figure 1). The optimized catalysts (e-Ni0.6Ru0.4@C and Co0.8Ru0.2Ox@NC) display outstanding HER and OER activities in alkaline media,1,2 which are among the best so far reported for various carbon-based electrocatalysts. The electrode pair of either e-Ni0.6Ru0.4@C‖e- Ni0.6Ru0.4@C or Co0.8Ru0.2Ox@NC‖Co0.8Ru0.2Ox@NC requires a low cell voltage for driving OWS to reach 100 or 500 mA cm-2, far outperforming the benchmark electrode pair of Pt/C‖RuO2. These carbon-based catalysts also exhibit superior durability as compared to those of precious catalysts. The experimental evidences combining with density functional theory (DFT) computations reveal the synergistic effect of core and carbon shell. Thus, our results may further shed light on how to design and optimize carbon-based electrocatalysts to achieve enhanced catalytic performance for electrochemical water splitting. References Feng, L.; et al., Ultrafine carbon encapsulated NiRu alloys as bifunctional electrocatalysts for boosting overall water splitting: morphological and electronic modulation through minor Ru alloying. Mater. Chem. A, 2020, 8, 9049–9057.Feng, L.; et al., Nanosheet-Derived Ultrafine CoRuOx@NC Nanoparticles with a Core@Shell Structure as Bifunctional Electrocatalysts for Electrochemical Water Splitting with High Current Density or Low Power Input. ACS Sustainable Chem. Eng. 2020, 8, 12089-12099. Figure 1. Schematic structure of e-Ni0.6Ru0.4@C. Figure 1