Doped Molybdenum Disulfide Research Articles

Vanadium-doped molybdenum disulfide film-based strain sensors with high gauge factor

This paper reports the piezoresistive performance of the two-dimensional (2D) material of vanadium (V)-doped molybdenum disulfide (MoS2) films based on sulfurization of sputtered Mo thin films. I–V characteristics indicate that V atom doping indeed decreases the resistivity of MoS2. Strain sensors based on V-doped MoS2 resistive elements were fabricated. By using a four-point bending method, a gauge factor (GF) of 140 under compressive and tensile strain conditions was obtained. The piezoresistive effect of V-doped MoS2 with different V sputtering conditions was also investigated. The doping method introducing V atoms as dopants is found to play an important role in enhancing piezoresistive performance.

Growth of \u2018W\u2019 doped molybdenum disulfide on graphene transferred molybdenum substrate

In the present study, a novel method has been carried out to grow tungsten (W) doped molybdenum disulfide (MoS2) on the graphene transferred TEM grid in a chemical vapor deposition (CVD) setup. Tungsten trioxide (WO3) has been used as a source for ‘W’ while ‘Mo’ has been derived from Mo based substrate. Different experimental parameters were used in this experiment. Higher gas flow rate decreases the size of the sample flake and on other side increases the dopant concentrations. The interaction mechanism between Mo, S, W and oxygen (O) have been explored. The influence of oxygen seems to be not avoidable completely which also imposes effective growth condition for the reaction of Mo with incoming sulfur atoms. The difference in the migration energies of Mo, WO3, S clusters on the graphene and the higher reactivity of Mo clusters over other possibly formed atomic clusters on the graphene leads to the growth of W doped MoS2 monolayers. Formation of MoS2 monolayer and the nature of edge doping of ‘W’ is explained well with the crystal model using underlying nucleation principles. We believe our result provide a special route to prepare W doped MoS2 on graphene substrate in the future.

Enhanced electrocatalytic hydrogen evolution performance of MoS2 ultrathin nanosheets via Sn doping

Two-dimensional (2D) transition-metal dichalcogenides (TMDs) have drawn much attention due to their unique physical and chemical properties. Molybdenum disulfide (MoS2) is particularly promising in hydrogen evolution reaction (HER) as a substitute for noble-metal catalysts. Although numerous attempts have been made to improve the HER activity of MoS2, engineering the MoS2-based electrocatalysts with activities similar to noble-metal catalysts remains challenging. Herein, we synthesize high-quality tin doped molybdenum disulfide (Sn-MoS2) ultrathin nanosheets by a g-C3N4 sacrificial template assisted thermolytic approach, and detailly investigate the role of Sn doping on the HER activity. The porous Sn-MoS2 nanosheets displays superior HER performance, exhibiting an overpotential of 28mV at 10mAcm−2 and a Tafel slope of 37.2mVdec−1 with an admirable stability. Compared to pristine MoS2 nanosheets, the significantly improved catalytic activity is ascribed to the increased active edge sites, enhanced intrinsic catalytic activity for each active site as well as accelerated electron transfer upon Sn doping. This work may provide guidelines for the design and synthesis of efficient non-precious HER catalysts.

MoS2 spaser

We present a comprehensive analysis of a spaser made of a circular shaped highly doped molybdenum disulfide (MoS2) resonator. “Spaser” is an acronym for “surface plasmon amplification by stimulated emission of radiation”–a nanoscale source of surface plasmons generated by stimulated emission in a plasmonic resonator which receives energy nonradiatively. By considering localized surface plasmon modes, operation characteristics of the model are analysed, and tunability of the design is demonstrated. We find the optimum geometric and material parameters of the spaser that provides efficient outputs and carryout a comparative analysis with a similar circular spaser made of graphene. Owing to physical and chemical properties of MoS2 and the active medium, the proposed design delivers efficient outputs in terms of spaser mode energy, operating thresholds, Q-factor, and electric field amplitude. Lower operating thresholds and higher mode energies are notable advantages of the design. Owing to having many superior features to existing similar designs, this MoS2 spaser may be much suited for applications in nanoplasmonic devices.

Carbon doped molybdenum disulfide nanosheets stabilized on graphene for the hydrogen evolution reaction with high electrocatalytic ability.

Fabricating a cost effective hydrogen evolution reaction catalyst without using precious metal elements is in crucial demand for environmentally-benign energy production. In this work, the thin and edge-rich molybdenum disulfide nanosheets, with carbon doped in the interlayers and decorated on graphene, were developed by a facile solvothermal process. The as-synthesized nanohybrids exhibited high catalytic ability for the hydrogen evolution electrochemical reaction with an onset overpotential of 0.165 mV and a Tafel slope of 46 mV dec(-1). Furthermore, the prepared nanohybrids also showed better durability and stability. Our work may lead to a potential method for in situ production of metal carbide-sulphur hybrid nanomaterials with promising applications for the hydrogen evolution reaction.