Probing into crystallography and morphology properties of MoS₂ nanoflowers synthesized via temperature dependent hydrothermal method

Abstract

This paper reports the formation of flower-like hierarchical molybdenum disulfide (MoS2) nanoparticles following a simple one-step hydrothermal process with varying temperatures (200 ⁰C and 220 ⁰C). The as-synthesized particles were examined crystallographically by x-ray diffraction (XRD) method which revealed the formation of hexagonal MoS2 (2H-MoS2). and that the crystallite size of the particles increased with increasing hydrothermal temperature. Surface morphological characteristics of the particles were investigated by a field emission scanning electron microscope (FESEM) and interesting details were revealed such as the rounded 3-D flower-like microstructure of the MoS2 particles and the petals of the flowers were composed of platelets built up by stacked-up MoS2 nanosheets. With the increase in hydrothermal temperature, the interlayer spacing of stacked layers of intense (002) plane is slightly decreased although the crystallinity of the material is improved. Both diameter and thickness of the nanoflowers and the nanoplatelets increased twice with increasing the temperatures. A visual crystallographic perspective was presented through simulation of 3-D wireframe unit cell associated with the individual lattice planes as observed in the XRD pattern of the samples. In addition, a plausible growth mechanism is proposed for the formation of the obtained MoS2 nanoflowers on the basis of experimental observations and analysis.

Synthesis and Characterization of Molybdenum- and Sulfur-Doped FeSe

“…The Mo can accelerate the transformation from Fe 7 Se 8 to tetragonal FeSe and the growth of grains by improving atomic diffusion, thus making the sintering process much faster than that in the undoped sample. The layered structure of the two samples that belong to the tetragonal phase is clear and confirms the XRD results with the presence of spherical shapes and flakes related to Fe 7 Se 8 and MoS 2 …”

“…This phenomenon results in alterations in the unit cell parameters and atomic arrangements, subsequently leading to shifts in the diffraction pattern. 28 3.2. Thermogravimetric Analysis.…”

“…The layered structure of the two samples that belong to the tetragonal phase is clear and confirms the XRD results with the presence of spherical shapes and flakes related to Fe 7 Se 8 and MoS 2 . 28 In Figure 3, we provide an insightful compositional mapping, which enables us to evaluate the distribution of different elements within both undoped FeSe 0.9 and Mo 0.1 Fe 0.9 Se 0.9 S 0.1 samples. This mapping provides valuable information regarding the spatial distributions of Fe, Se, Mo, and sulfur within the samples, thus confirming the molar ratio of the starting materials employed in the experiment.…”

“…The shifts in peak positions, specifically the (011) and (101) peaks, can indeed be attributed to the successful incorporation of sulfur and molybdenum into the FeSe crystal lattice. This phenomenon results in alterations in the unit cell parameters and atomic arrangements, subsequently leading to shifts in the diffraction pattern …”

Exploring the Influence of Temperature and Time on the Formation and Properties of 3D Flower-Like MoS2 Nanostructures Synthesized via Hydrothermal Method

“…It has been shown that the synthesis method can play a crucial role not only in synthesizing the nanostructures with desired morphology but also in controlling their physiochemical properties. [23][24][25][26][27] Various physical as well as chemical methods can be used to synthesized MoS 2 nanostructures. 28 Depending on the synthesis method, MoS 2 nanostructures can be formed with different morphologies such as 2D sheets, plates, tubes, ribbons, 3D flower, sphere and so on.…”