Charge Transfer in the MoS₂/Carbon Nanotube Composite

Abstract

Composite MoS 2 /carbon nanotube material has been produced by hydrothermal decomposition of a mixture of multiwall carbon nanotubes (CNTs) and a water solution of ammonium molybdate and thiourea. Transmission electron microscopy and Raman spectroscopy showed formation of MoS 2 layers on the CNT surface and MoS 2 flakes. X-ray photoelectron spectroscopy revealed a downshift of C 1s peak of the composite as compared to the pristine CNT sample that was related to charge transfer between the components. This fact was confirmed by near-edge X-ray absorption fine structure spectroscopy which detected a decrease of intensity of π* resonance in the C K-edge spectrum after the MoS 2 deposition. Quantum-chemical calculations of a CNT@MoS 2 model showed a positive charging of the CNT surface. Comparison of field emission characteristics of CNTs and the composite indicated lowering of the voltage threshold in the latter sample.

SnSx (x = 1, 2) Nanocrystals as Effective Catalysts for Photoelectrochemical Water Splitting

“…The S 2p peaks (Figure 4b) in the SnS2 thin films were observed at 161.7 eV (S 2p1/2), 163.6 eV (S 2p3/2), and 169.0 eV, which corresponds to S 2− , S2 2− and sulfone (S 4+ ), respectively [38]. S 4+ species behaves more likely as SOx groups, which can be dissolved in the solutions or washed away from the sample [39]. However, the SnS films show a single peak at 161.8 eV (S 2p1/2), indicating the existence of S 2− ions in the films [11,16,40].…”

“…S 4+ species behaves more likely as SO x groups, which can be dissolved in the solutions or washed away from the sample [39]. However, the SnS films show a single peak at 161.8 eV (S 2p 1/2 ), indicating the existence of S 2− ions in the films [11,16,40].…”

Molybdenum disulfide / mesoporous carbon nanocomposite as electrode material for supercapasitors

“…The obtained result can be explained by a synergetic effect of the nanocomposite materials, carbon acts as a donor of electrons for molybdenum disulphide, which at low frequencies and at room temperature is usually n-type semiconductor with hopping conductivity, i. e. the exchange of electrons between Mo ions. The excess electrons from the electron donor would be expected to reduce the hardness of the electron transfer, and, according to [14], in the partial electron transfer from graphene (or carbon layer) to MoS 2 layers, each carbon atom donates ca. 0.027e to MoS 2 and the transferred electrons are located on sulphur atoms.…”

Hydrogen Evolution Reaction Property in Alkaline Solution of Molybdenum Disulfide Modified by Surface Anchor of Nickel–Phosphorus Coating

“…The peak appearing at 162.9 eV (Ni-LP/MoS2) and 162.5 eV (Ni-MP/MoS2) may be indexed to S2O3 2− , which can be attributed to the oxidation of sulfur element during the hydrothermal process. The peaks at 170.1 eV (Ni-LP/MoS2) and 169.1 eV (for Ni-MP/MoS2 and Ni-HP/MoS2) are identified to the S 4+ state in SO3 2− , which tends to locate at edges of MoS2 layers [30,31], and also suggesting the oxidation of MoS2. …”

“…Compared with that of MoS2, as demonstrated by Figure 2, except for S, Mo, and O elements, the existence of Ni and P elements for the three Ni-P/MoS2 composites reveals the anchor of Ni-P coatings on the surface of MoS2. The presence of O element may be assigned to the oxidation of MoS2 particles and Ni-P coatings in air and/or the hydrothermal synthesis process [29,30]. The P and Ni contents (at %) for both Ni-MP/MoS2 and Ni-HP/MoS2 samples are very higher than that of Ni-LP/MoS2 sample, and they follow the order of Ni-LP/MoS2 < Ni-MP/MoS2 < Ni-HP/MoS2; however, S and Mo contents for these three composites are in a reverse trend (Ni-LP/MoS2 > Ni-MP/MoS2 > Ni-HP/MoS2).…”