Characterization and study of reduction and sulfurization processing in phase transition from molybdenum oxide (MoO2) to molybdenum disulfide (MoS2) chalcogenide semiconductor nanoparticles prepared by one-stage chemical reduction method

Tekalgne

Intl J of Energy Research

et al. 2022

Summary In this study, different morphologies of molybdenum disulfide (MoS2), including MoS2 nanoparticle (NP), MoS2 nanoflower (NF), MoS2 nanosphere (NS), MoS2 nanohollow (NH), and MoS2/MoO2 composite, are successfully synthesized via a facile‐route hydrothermal process employing different solutions. The structure and chemical bonding of the different morphologies of MoS2 are investigated via X‐ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and X‐ray photoelectron spectroscopy (XPS). Thereafter, the synthesized materials are applied to the hydrogen evolution reaction (HER) employing a three‐electrode system in a standard acidic medium (0.5 M H2SO4). The MoS2 NH exhibits higher performance: an overpotential of −230 mV at −10 mAcm−2, a Tafel slope of 64 mVdec−1, a high double‐layer capacitance (Cdl) of 11.98 mFcm−2 and larger BET surface area (22.59 m2/g), as well as super stability after stability tests, representing the best catalytic behavior among the synthesized materials. The results indicate that the electrocatalytic efficiencies of materials depend on their morphologies which is highly related to the surface area of catalysts. The results avail a novel avenue for synthesizing the various morphologies of MoS2, as well as the new morphology of MoS2 (MoS2 NH). It can be a promising material for electrocatalytic and energy‐storage applications.

“…In the XRD patterns of MoS 2 /MoO 2 composite, other sharp peaks were observed at 2θ = ~26°, 37°, and 53.5° they revealed the presence of MoO 2 (JCPDS No. 32‐0671) 45,46 …”

Section: Resultsmentioning

confidence: 99%

“…32-0671). 45,46 The Raman spectra of the prepared materials, which exhibited numerous peaks, were also obtained to confirm the structures and chemical bonds therein (Figure 3). The detections of three peaks, namely E 1g , E 2g , and A 1g at 283, 376, and 402 cm À1 , confirmed the presence of MoS 2 , respectively.…”

Section: Characterization Of Materialsmentioning

confidence: 93%

Control of the morphologies of molybdenum disulfide for hydrogen evolution reaction

Tekalgne

Intl J of Energy Research

et al. 2022

“…Furthermore, in the range of below 1000 cm -1 , the characteristic peaks of MoO2 mostly shifted to the left. Raman peaks at 970, 797, 674 cm -1 are seemingly originated from position 993, 820 and 663 cm -1 , corresponding to Mo = O bond stretching (Ag, υas), Mo = O bond stretching (Ag, υs) and O -Mo -O bond stretching (B2g, B3g, υa) [18].…”

Section: Resultsmentioning

confidence: 99%

One-step Synthesis of Molybdenum Oxide/graphene Composites

Minh¹,

Minh²,

Trung³

et al. 2021

MaP

We herein introduce a new approach to synthesize MoO2/graphene composites via plasma-enhanced electrochemical exfoliation process. Our samples were prepared by electrifying graphite rods in (NH4)2Mo7O24 solution under a DC voltage of 70V. By controlling the experimental parameters such as the initial ratio of [Mo7O24]2– precursor, the current and time, we can modify the size and the size distribution of MoO2 nanoparticles on graphene sheets. The composites were characterized with Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray Diffraction and Raman Spectroscopy.

“…2(b), the bulk MoS 2 exhibits strong characteristic absorption peaks at the positions of 3404 cm À1 and 1635 cm À1 corresponding to hydroxyl groups, and another two strong absorption peaks at 469 cm À1 and 600 cm À1 correspond to the vibrations of the Mo-S bond. 46 Compared with bulk MoS 2 , two positions of 2970 cm À1 and 2926 cm À1 correspond to the stretching vibration of C-H, and the positions of 1604 cm À1 , 1377 cm À1 and 1047 cm À1 correspond to the skeletal telescopic vibration of SC]C aromatic ring, the C-H symmetrical bending vibration of methyl group and the stretching vibration of C-O. The position of 883 cm À1 corresponds to the bending vibration of sC-H. All these can be attributed to the characteristic vibration of the functional group of the surfactant sodium cholate.…”

Section: Characterization Of Mos 2 Nanosheets and Au@mos 2 Composite Nanosheetsmentioning

confidence: 99%

Construction of a Au@MoS₂ composite nanosheet biosensor for the ultrasensitive detection of a neurotransmitter and understanding of its mechanism based on DFT calculations

Liu

Dai

et al. 2022

RSC Adv.