Electron beam-assisted synthesis of porous Cu2MoS4 nanocubes for efficient all-pH electrocatalytic hydrogen evolution†

Transition metal sulfides are promising non-noble metal catalysts for hydrogen production through electrochemical water splitting due to their rich redox behaviors, good conductivity and stability. Herein, mesoporous Cu₂MoS₄ nanocubes were rapidly synthesized at room temperature via a novel electron beam irradiation-assisted method. During the electron beam irradiation process, a large number of free radicals were produced. These radicals are highly active and effectively accelerate the rapid formation of Cu₂MoS₄ nanocubes with I-phase. The as-obtained Cu₂MoS₄ nanocubes presented a mesoporous structure, which not only provides abundant electrocatalytic active sites but also facilitates the diffusion of electrolyte and the overflow of H₂ bubbles. As a result, the titled catalyst exhibits good electrocatalytic activity toward the hydrogen evolution reaction (HER) in acidic, neutral and alkaline electrolytes. Specifically, the catalyst with an irradiation dose of 300 kGy exhibited the best HER performance with low overpotentials of 160.2 mV, 256.2 mV and 225 mV to achieve a current density of 10 mA cm⁻² in 0.5 M H₂SO₄, 1 M PBS and 1 M KOH, respectively. This work demonstrates the effectiveness of electron beam-assisted synthesis in producing well-defined nanostructured catalysts for water splitting.