Hierarchical core–shell heterostructure FeMoS@CoFe LDH for multifunctional green applications boosting large current density water splitting

Abstract

It is crucial to develop catalysts that can work efficiently and stably at high current densities to meet the needs of industrial production. This work proposes the deposition of CoFe LDH nanosheets on the surface of FeMoS nanorods to synthesize FeMoS@CoFe-LDH. The core–shell structure can effectively enhance stability and expose more active sites. In addition, the electronic structure was optimized through interface electronic modulation, accelerating the catalytic kinetics at high current density. The FeMoS@CoFe LDH achieves remarkable bifunctional electrocatalytic performance for overall water splitting at a large current density of 1000 mA cm⁻², showing overpotentials of 376 mV for the HER and 320 mV for the OER. Meanwhile, it only requires 1.79 V to drive the water splitting at 500 mA cm⁻² and can maintain stable operation for 50 h, which is significantly better than the performance of recently reported nonprecious metal catalysts. In order to promote the practical industrial production of water electrolysis, a capillary-fed electrolysis cell-connected drainage device has been applied to achieve more efficient gas–liquid separation. In addition, solar and wind energy are utilized to drive electrocatalysts for water splitting, achieving an environmentally friendly approach. This work provides strategies and directions for the rational design of efficient catalysts in industrial water electrolysis.