Interfacial and Electronic Modulation of W Bridging Heterostructure Between WS₂ and Cobalt-Based Compounds for Efficient Overall Water Splitting

The development of high performance electrocatalysts for effective hydrogen production is urgently needed. Herein, three hybrid catalysts formed by WS₂ and Co-based metal–organic frameworks (MOFs) derivatives are constructed, in which the small amount of W in the MOFs derivatives acts as a bridge to provide the charge transfer channel and enhance the stability. In addition, the effects of the surface charge distribution on the catalytic performance are fully investigated. Due to the optimal interfacial electron coupling and rearrangement as well as its unique porous morphology, WS₂@W-CoP_x exhibits superior bifunctional performance in alkaline media with low overpotentials in hydrogen evolution reaction (HER) (62 mV at 10 mA cm⁻²) and oxygen evolution reaction (OER) (278 mV at 100 mA cm⁻²). For overall water splitting (OWS), WS₂@W-CoP_x only requires a cell voltage of 1.78 V at 50 mA cm⁻² and maintains good stability within 72 h. Density functional theory calculations verify that the combination of W-CoP_x with WS₂ can effectively enhance the activity of OER and HER with weakened OH (or O) adsorption and enhanced H atom adsorption. This work provides a feasible idea for the design and practical application of WS₂ or phosphide-based catalysts in OWS.