The Combination of MoS2/WO3 and Its Adsorption Properties of Methylene Blue at Low Temperatures

Abstract

It was found previously that neither monomer MoS 2 nor WO 3 is an ideal material for the adsorption of organic dyes, while MoS 2 /WO 3 composites synthesized by a two-step hydrothermal method have outstanding adsorption effects. In this work, the chemical state of each element was found to be changed after combination by X-ray photoelectron spectroscopy analysis, which lead to their differences in adsorption performance. Moreover, the adsorption test of methylene blue on MoS 2 /WO 3 composites was carried out under a series of temperatures, showing that the prepared composites also had appreciable adsorption rates at lower temperatures. The adsorption process could be well described by the Freundlich isothermal model and the pseudo-second order model. In addition, the particle-internal diffusion model simulation revealed that the internal diffusion of the particles played an important role in the whole adsorption process.

Temperature-Based Selective Detection of Hydrogen Sulfide and Ethanol with MoS2/WO3 Composite

“…9 Panel c displays the prominent peaks for the W 6+ oxidation state, which correspond to W 4f 7/2 and W 4f 5/2 at 38.7 and 36.0 eV, respectively. 41,47 In addition to these two peaks of W 6+ , one more low-intensity peak at the binding energy of 32.4 is detected, confirming the presence of the W 5+ oxidation state in the hybrid materials. 48 Two peaks of the O 1s spectra in panel d correspond to oxygen in WO 3 .…”

“…These belong to +4 oxidation state of Mo and govern the highest signal in the spectra, while the other low-intensity peak at 232.1 and another one at 235.6 eV corresponds to Mo 6+ , implying the presence of MoO 3 or MoO 4 2– , which may be formed during the synthesis of the materials. ,, The Mo 4+ peaks are at 228.6 and 231.5 eV, and the S 2p region matches the 2H-phase of MoS 2 . , In panel b, the two major peaks of S 2p centered at 161.4 and 163.0 eV due to S 2– 2p 3/2 and S 2– 2p 1/2 can be seen. , The low-intensity high-energy component at 168.5 eV can be assigned to S 6+ species in sulfate groups (SO 4 2– ) . Panel c displays the prominent peaks for the W 6+ oxidation state, which correspond to W 4f 7/2 and W 4f 5/2 at 38.7 and 36.0 eV, respectively. , In addition to these two peaks of W 6+ , one more low-intensity peak at the binding energy of 32.4 is detected, confirming the presence of the W 5+ oxidation state in the hybrid materials . Two peaks of the O 1s spectra in panel d correspond to oxygen in WO 3 .…”

MoS2/WO3Nanosheets for Detection of Ammonia

“…In short, the peaks corresponding to Mo 3d, S 2p, W 4f, and O 1s in the composite material are shifted to higher binding energies when compared with individual MoS 2 and WO 3 . This indicates that composite is successfully obtained and a strong electronic interaction between MoS 2 and WO 3 exists …”

“…This indicates that composite is successfully obtained and a strong electronic interaction between MoS 2 and WO 3 exists. 61 The gas sensing characteristics of nanostructured materials based devices strongly depend upon the porosoty and available specific surface area. The nitrogen adsorption−desorption isotherms of MoS 2 and its composite with WO 3 are shown in the Supporting Information (Figure S4).…”

Ex Situ Synthesis and Characterizations of MoS2/WO3 Heterostructures for Efficient Photocatalytic Degradation of RhB

“…A sharp peak of Mo-OH vibration was observed for both heterostructures spectra, but it was absent in the WO 3 spectrum and appeared as a slight impression in the MoS 2 spectrum. It is inferred that both heterostructures were prepared by strong forces, which help composite molecules bind firmly together, and H-bonding due to water crystallization plays a vital role in this regard [ 12 , 13 ].…”