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Hydrogen storage holds a crucial place for the future of the world in terms of green energy. Two-dimensional materials, in particular, are important in this regard. The aim of this study is to evaluate the performance of MoS 2 which is one of the most popular member of two-dimensional materials family. To do this, bulk and exfoliated MoS 2 were used. Firstly, the liquid phase exfoliation method was employed to obtain exfoliated MoS 2 layers. Then, the hydrogen storage potential of the bulk and exfoliated MoS 2 was addressed under 1, 3, 5, 7, and 9 bar hydrogen pressure. After the absorption process, all the samples were characterized using XRD, Raman Spectrometer, and BET ahead of evaluating their hydrogen storage potential. The XRD pattern showed that the peak positions of bulk and exfoliated MoS 2 were not affected critically by hydrogen storage. In the Raman spectra, the A 1g and E 2g 1 peaks of all hydrogenated materials shifted to low wavelengths. Moreover, the BET measurements revealed that the specific surface area and the pore size of the bulk MoS 2 were 12.31 m2/g and ≤67.46 nm respectively. Additionally, the specific surface area and the pore size of the exfoliated MoS 2 were 23.16 m2/g and ≤69.28 nm, respectively. The hydrogen storage potential of the bulk and the exfoliated MoS 2 was evaluated through an MFC in sccm unit. The bulk and exfoliated MoS 2 stored 220 and 450 sccm hydrogen, respectively. Besides, the weight percent hydrogen storage for H–MoS 2 and H-exfoliated MoS 2 was determined to be 1.2 and 2.4 wt%, respectively. In summary, this study has shown that exfoliated MoS 2, one of the two-dimensional materials, can play a critical role for hydrogen storage due to their high specific surface area. • Exploring MoS 2 for hydrogen storage, both in bulk and exfoliated forms, reveals promising 2D material capabilities. • Exfoliated MoS 2 layers were successfully produced by liquid phase exfoliation method. • AFM confirms formation of few-layer nanosheets with thicknesses ranging from 2 to 6 nm (2–5 layers). • Exfoliated MoS 2 , stores up to 450 sccm and 2.4 % wt of hydrogen, surpassing the hydrogen capacity of MoS 2 at 7 bar. [ABSTRACT FROM AUTHOR]

In this study, MoS2 thin films were grown using two-step approach, which is based on employing both PVD and CVD techniques. The films were obtained initially by sputtering 1nm Mo film in the PVD system and followed by sulphurization of the film in CVD at 700oC. The grown films were optimized employing different sulphurization times. The main difference in our study from the current literature is using preheated CVD furnace (700oC) ahead of sulphurization. The films quality are then investigated using Raman and Photoluminance spectrometer as well as AFM measurements. The Raman spectrums indicate that two characteristic vibration modes of 2H-MoS2 phase were observed in all samples, however, vibration modes of 1TMoS2 phase were also observed in some films at low sulphurization time. These results were also in line with PL measurements that confirm the direct band transition of the MoS2 films. The surface topography of the films were investigated by AFM for MoS2 films obtained by the sulfurization of 1 nm-thick Mo film in 15 minutes at 700oC which shows MoS2 crystals in triangle shape. [ABSTRACT FROM AUTHOR]

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This paper reports on a few layer boron doped graphene with high homogeneity, stability and size. To achieve this, we employed diborane to synthesize a boron doped graphene film in a CVD system. During synthesis, we investigated the effect of diborane flow and growth time on copper foil to optimize doped graphene growth conditions. Raman spectroscopy, XPS, EDXS and ellipsometer were employed for the characterization of the doped graphene films. The results of our study enabled the design of a recipe for thin film boron doped graphene growth with optimum optical transmission values. We further found that increasing the flow of diborane from 10 to 30 sccm and growth times from 10 to 30 min leads to the formation of thicker graphene films. However, we discovered that a few layer graphene film with high homogeneity could be obtained for the film that was grown using 10 sccm diborane along with 30-min growth time. The doping was confirmed by observing the shift in the Raman spectra peaks and XPS measurements in comparison to single layer pristine graphene. The study also revealed that boron atoms substituted carbon atoms in the honeycomb structure as confirmed by XPS measurements, which also provide the doping rate to be 2.4%. Our study has significant implications regarding substitutional doping which enables the doping to be stable for a long time, and this is crucial for the doped graphene to be employed in semiconducting technology particularly in optoelectronics. • Large area a few layer boron doped graphene is successfully synthesized using diborane in CVD. • Diborane flow rate and growth time are found to be very effective on the doping and thickness of the graphene film. • Boron doping is found to be stable and homogeneous thanks to in-situ doping approach. • Boron doped graphene is essential for optoelectronic applications. [ABSTRACT FROM AUTHOR]