Improvement of MoS2 electrocatalytic activity for hydrogen evolution reaction by ion irradiation

Molybdenum disulfide (MoS2) is considered promising noble metal-free catalysts for the hydrogen evolution reaction (HER). Whereas the bulk MoS2 does not exhibit significant activity, the catalytic properties of various nanostructures are noticeable. Therefore we synthesized flower-like molybdenum disulfide with the simple, one-step hydrothermal method. To enhance the catalytic activity of the material, low-energy ion irradiation is employed. As-prepared MoS2 is irradiated with hydrogen and carbon ions of various energies (20–40 keV) and fluences (1014-1017 ion/cm2). Our results show that irradiation has beneficial influence on MoS2 catalytic activity toward hydrogen evolution reaction. By producing morphological changes and defects in the structure, ion irradiation also impacts the conductivity of the material, which shows predominant effect on hydrogen evolution. The increase of current density at an overpotential of 300 mV with hydrogen ion irradiation is even 6 times higher than for as-synthesized catalyst.