Synthesis of a finger-like MoS₂@VS₂ micro–nanocomposite with enhanced field emission performance

Abstract

A MoS2@VS2 micro–nanocomposite showed enhanced field emission properties benefiting from the synergy of the two materials.

In2Se3 Nanocubes as High Current Density Cold Cathode Materials

“…Changqing Song et al have reported highly efficient FE properties of a novel layered VS 2 /ZnO nanocomposite and flexible VS 2 nanosheet emitters . Very recently, synthesis of a finger-like MoS 2 @VS 2 micro–nanocomposite with enhanced FE performance has been reported . The group working from Pune University has carried out studies on FE performance of variety of 2D TMD nanostructures and nanocomposites. − The group has studied FE behavior of In 2 Se 3 nanowires synthesized by simple thermal evaporation in a Quartz tube furnace …”

Regulating the Metal Concentration for Selective Tuning of VS2/MoS2 Heterostructures toward Hydrogen Evolution Reaction in Acidic and Alkaline Media

“…The (002) peak of MoS 2 and the (001) peak of VS 2 appeared almost at the same 2θ value (V and M stand for VS 2 and MoS 2 , respectively); thereby, a sharp peak appeared, exhibiting the successful formation of the heterostructure. Moreover, the crystal growth of the heterostructure occurred along the Z (axis) direction as confirmed by the intense peak at the lower 2θ position. , Except for the crystal growth plane, the heterostructure does not show intense peaks, indicating that the crystallinity is monitored by the heterostructure growth. − As a result, more edges and active sites are exposed to the formation of heterostructures, significantly enhancing the catalytic performance for HER. Furthermore, inert basal planes can be exposed during heterostructure growth via lateral and vertical epitaxy mechanisms, indicating the improved HER activity.…”

“…The percentage area of the V 3+ state was higher in VMS1 than in VMS2, indicating the formation of dangling sulfur atoms, which can act as active sites for hydrogen absorption and desorption as confirmed from Figure S1d. , Interestingly, the Mo 3d peaks for all the VS 2 /MoS 2 heterostructures depicted a shift toward a lower binding energy compared with pure MoS 2 . The observed peak shifts demonstrated that the electrons may transfer from VS 2 nanosheets to MoS 2 nanopetals as the former has a smaller work function and thereby a strong coupling effect between VS 2 and MoS 2 was formed at the heterostructure interface. ,, Moreover, the strong electronic interaction between VS 2 and MoS 2 in the heterostructure provided a conducting architecture, and therefore, the electrochemical performance was improved. Figure a–c shows the two characteristic peaks of S 2– species, which correspond to the S 2p3/2 and S 2p1/2, with a spin-orbit splitting of 1.2 eV. − The XPS results were in good agreement with the successful formation of the heterostructure as reported in the literature. ,− Moreover, the obvious binding energy shifts for Mo 3d, V 2p, and S 2p XPS spectra suggested a strong electronic interaction between the MoS 2 and VS 2 within the different compositions of the heterostructures.…”

“…The nanosheet-like VS 2 and flower-like MoS 2 are assigned to the JCPDS database of VS 2 (#89-1640) and MoS 2 (#37-1492), respectively. The distinct peaks of VS 2 nanosheets appeared at 14.35, 31.12, 34.40, 36.58, and 46.35° due to the formation of the (001), (100), (011), (101), and (012) crystal planes, respectively. − ,− The major peaks of pure MoS 2 located at 13.04, 33.79, 39.04, 49.09, and 57.39° were ascribed to the crystal planes of (002), (100), (003), (105), and (110), respectively. The intense peaks of both MoS 2 and VS 2 suggested the crystalline nature of the TMDS in the heterostructure.…”

“…At a higher current density, both VMS3 and VMS2 provided parallel overpotential values, suggesting similar catalytic activity. Therefore, H adsorption on the electrode surface is hardly the necessary criteria for the VS 2 and MoS 2 -based heterostructure. − , In brief, the H adsorption and charge transfer kinetics play a key role in HER irrespective of the electrolyte medium. At a higher current density, both the charge transfer and H adsorption phenomenon occur in a parallel way.…”