Amorphous/crystalline AgS@CoS core@shell catalysts for efficient oxygen evolution reaction

Abstract

The core@shell structure materials with the synergistic effect have been confirmed as promising catalysts for oxygen evolution reaction (OER). However, the conventional catalysts with crystalline phase suffer from deficient active sites, elemental dissolution, and structural collapse during OER catalysis, which results in the limited OER performance. Herein, we introduced the amorphous phase structure by controllable wet-chemical sulfuration strategy, thus to prepare the amorphous/crystalline (a/c) AgS@CoS core@shell catalysts. Benefitting from the core@shell construction with synergistic interaction, a/c heterophase with well-balanced catalytic activity and stability, favorable sulfides components with positive oxysulfide reconstructed layer formation, the optimized AgS@CoS-2 catalysts displayed superior OER catalytic behaviors with a low overpotential of 260 mV and Tafel slope of 64.4 mV/dec on the current density of 10 mA/cm², surpassing the counterpart catalysts and commercial RuO₂ catalysts. Meanwhile, the AgS@CoS-2 catalysts possessed remarkable OER catalytic stability, as well as the favorable overall water splitting performance.