Sulfur Vacancy-Engineered Co 3 S 4 /MoS 2 -Interfaced Nanosheet Array for Enhanced Alkaline Overall Water Splitting.

Electrochemical water splitting, a crucial reaction for renewable energy storage, demands highly efficient and stable catalysts. Defect and interface engineering has been widely acknowledged to play a pivotal role in improving electrocatalytic performance. Herein, we demonstrate a facile strategy to construct sulfur vacancy (S)-engineered CoS/MoS-interfaced nanosheet arrays to modulate the interface electronic structure in situ reduction with NaBH. The abundant sulfur vacancies and well-arranged nanosheet arrays in S-CoS/MoS lead to pronounced electrocatalytic properties for hydrogen and oxygen evolution reactions (HER/OER) in an alkaline medium, with observed overpotentials of 156 and 209 mV at 10 mA cm, respectively. Additionally, as a bifunctional electrocatalyst, S-CoS/MoS requires a cell voltage of 1.67 V at 10 mA cm for overall water splitting and exhibits long-term stability with activity sustained for more than 20 h. This study provides a novel approach to producing transition metal compound-interfaced electrocatalysts with rich vacancies under mild conditions, showcasing their potential for efficient water splitting applications.