Interface Engineered W_xC@WS₂ Nanostructure for Enhanced Hydrogen Evolution Catalysis

For increasing scalability and reducing cost, transition metal dichalcogenides-based electrocatalysts presently have been proposed as substitutes for noble metals to generate hydrogen, but these alternatives usually suffer from inferior performance. Here, a Ravenala leaf-like W_xC@WS₂ heterostructure is grown via carbonizing WS₂ nanotubes, whose outer walls being partially unzipped along with the W_x C “leaf-valves” attached to the inner tubes during the carbonization process. This heterostructure exhibits a catalytic activity for hydrogen evolution reaction with low overpotential of 146 mV at 10 mA cm⁻² and Tafel slope of 61 mV per decade, outperforming the performance of WS₂ nanotubes and W_xC counterparts under the same condition. Density functional theory calculations are performed to unravel the underlying mechanism, revealing that the charge distribution between W_xC and WS₂ plays a key role for promoting H atom adsorption and desorption kinetics simultaneously. This work not only provides a potential low-cost alternative for hydrogen generation but should be taken as a guide to optimize the catalyst structure and composition.