Effective Fabrication and Electrochemical Oxygen Evolution Reaction Activity of Gold Multipod Nanoparticle Core-Cobalt Sulfide Shell Nanohybrids

Abstract

Inorganic hybrid materials with anisotropic noble-metal nanoparticle cores and cagelike transition-metal chalcogenide shells are promising candidates for a wide variety of applications. Herein, we report an effective fabrication method for gold multipod nanoparticle (GMN) core-cobalt sulfide shell (GMN@CoxSy) nanostructures. The unique cagelike morphology is successfully acquired within nanohybrids (GMN@CoxSy nanocages). The cobalt-based metal-organic frameworks can act as versatile sacrificial templates to the desired hybrid nanomaterials through solution-based etching approaches without any undesirable reshaping of GMNs, which are embedded within. Examination of the electrocatalytic oxygen evolution reaction (OER) of the prepared nanohybrids reveals that a type of GMN@CoxSy nanohybrid shows a substantially lower overpotential (η) value (345 mV) compared with those of GMNs (617 mV) and CoxSy nanomaterials (418 mV) at a current density of 10 mA cm-2. The enhanced OER performance is mainly attributed to the highly effective core-shell interfaces stemming from the unique multibranch topologies of the GMN cores as well as the optimized cobalt sulfide shells of the nanohybrids. © 2019 American Chemical Society.