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

Abstract

Summary: Molybdenum and tungsten carbides (Mo2C 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-Mo2C heterostructure may exert a high HER performance since the hybridization of WC and Mo2C can optimize the proton adsorption energy and energy barrier for water dissociation. To test this predication, we prepare the WC-Mo2C heterostructure on a flexible carbon cloth (CC). The obtained WC-Mo2C@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-Mo2C@CC cathode and a NiFe-LDH@Nif 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.

Keywords

• DFT theoretical calculation
• carbides
• heterojunction
• alkaline HER