Charge self-regulation in 1T'''-MoS2 structure with rich S vacancies for enhanced hydrogen evolution activity

Abstract

Active electronic states in transition metal dichalcogenides are able to prompt hydrogen evolution by improving hydrogen absorption. However, the development of thermodynamically stable hexagonal 2H-MoS2 as hydrogen evolution catalyst is likely to be shadowed by its limited active electronic state. Herein, the charge self-regulation effect mediated by tuning Mo−Mo bonds and S vacancies is revealed in metastable trigonal MoS2 (1T'''-MoS2) structure, which is favarable for the generation of active electronic states to boost the hydrogen evolution reaction activity. The optimal 1T'''-MoS2 sample exhibits a low overpotential of 158 mV at 10 mA cm−2 and a Tafel slope of 74.5 mV dec−1 in acidic conditions, which are far exceeding the 2H-MoS2 counterpart (369 mV and 137 mV dec−1). Theoretical modeling indicates that the boosted performance is attributed to the formation of massive active electronic states induced by the charge self-regulation effect of Mo−Mo bonds in defective 1T'''-MoS2 with rich S vacancies.

Phase Engineering of Molybdenum Dichalcogenide to Anion-Tunable Polyphasic Quaternary Chalcogenide (2H/1T/1T′) MoSxSeyTez (x + y + z = 2) Amplifies the Growth of H2 Electrolytically

“…These reduced binding energies imply the formation of the (2H/1T/1T′) phase and the partial charges transferred from active Mo−Mo bonds to nearby chalcogen atoms. 45 Furthermore, when determining multiple-phase content from XPS analysis (Figure 7d), MSST-2 shows three different phases, i.e., semiconducting 2H (29.7%), metallic 1T (33.54%), and semimetallic 1T′ (36.76%). On the other side, a binary mix phase is obtained from MoSSe, MoSeTe, and MoSTe with a phase percentage of (2H/1T, 41.1/58.9%), (2H/1T, 28.4/71.6%), and (2H/1T′, 87.6/12.4%), respectively.…”

Interface engineering of porous Co(OH)2/La(OH)3@Cu nanowire heterostructures for high efficiency hydrogen evolution and overall water splitting

“…6D and E). The changes in the electronic structure of Co could induce the electron rearrangement of the adjacent O atom in CH/LH@Cu NW-2, [57][58][59][60] which is proved by the shi of O 1s peaks in heterostructures (Fig. S20 †).…”

[MoS] Insertion Chains Induced Small-Polaron Collapse in MoS2 2D Layers: A Novel Mo2S3 Anode for Ultrafast Sodium Storage

“…The peak at 350.5 cm − 1 is ascribed to the vibration of Mo atoms in octahedral coordination, which is absent in MoS 2 . 57 The electrical properties of Mo 2 S 3 were further investigated by a physical property measurement system. The resistivity of Mo 2 S 3 is positively correlated to temperature, indicating the metallic behavior of Mo 2 S 3 (Fig.…”