Computation-guided design and preparation of durable and efficient WC-Mo2C heterojunction for hydrogen evolution reaction

Abstract

Molybdenum and tungsten carbides (Mo 2 C and WC) are promising catalysts for hydrogen evolution reaction (HER), but their electrocatalytic activities are still inferior to theoretical predictions. Herein, density functional theory (DFT) calculations imply that WC-Mo 2 C heterostructure may exert a high HER performance since the hybridization of WC and Mo 2 C can optimize the proton adsorption energy and energy barrier for water dissociation. To test this predication, we prepare the WC-Mo 2 C heterostructure on a flexible carbon cloth (CC). The obtained WC-Mo 2 C@CC exhibits notable HER activity ( η10 = 122 mV; η500 = 309 mV) and stability (continuous 100 h at 500 mA cm −2 ) in alkaline media. Furthermore, a solar-panel-driven electrolyzer, including the WC-Mo 2 C@CC cathode and a NiFe-LDH@Ni f anode, operates at 10 mA cm −2 with a cell voltage of 1.51 V in 10 M KOH at 70°C, demonstrating its potential for practical applications. Overall, this work offers an atomic-level insight into designing advanced carbide HER electrocatalysts. • WC-Mo 2 C heterostructures are prepared by one-step co-deposition • WC-Mo 2 C show competitive alkaline catalytic HER performance • The optimized ΔG H∗ and super hydrophilic nature account for its good HER activity • A water electrolyzer driven by solar energy is operated at industrial conditions WC-Mo 2 C heterostructures are prepared by one-step co-deposition in KF-B 2 O 3 -Na 2 WO 4 -Na 2 MoO 4 molten salts by Liu et al. The WC-Mo 2 C heterostructures show a high HER performance owing to the optimized ΔG H∗ and low energy barrier for water spitting.