Neutron spectroscopy study of the diffusivity of hydrogen in MoS2

The diffusion of hydrogen adsorbed inside layered MoS2 crystals has been studied by means of quasi-elastic neutron scattering, neutron spin-echo spectroscopy, nuclear reaction analysis, and X-ray photoelectron spectroscopy. The neutron time-of-flight and neutron spin-echo measurements demonstrate fast diffusion of hydrogen molecules parallel to the basal planes of the two dimensional crystal planes. At room temperature and above, this intra-layer diffusion is of a similar speed to the surface diffusion that has been observed in earlier studies for hydrogen atoms on Pt surfaces. A significantly slower hydrogen diffusion was observed perpendicular to the basal planes using nuclear reaction analysis.

Automated summary

The study demonstrates that the diffusion of hydrogen molecules inside layered MoS2 crystals depends on their direction parallel and perpendicular to the basal planes. Within the two-dimensional crystal layers, hydrogen molecules diffuse quickly, while diffusion perpendicular to the basal planes is significantly slower.