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Vanadium disulfide (VS2) is an important member of the transition metal dichalcogenides (TMDs) family, which offers high conductivity. In nature, it can exist in two phases, i.e., 1T and 2H. Herein, we have fabricated the metallic 1T VS2‐based in‐plane micro‐supercapacitor (MSC) by a facile mask‐assisted printing technique. Initially, the 1T VS2 nanosheets were synthesized using a simple one‐pot hydrothermal route. The material characterizations have claimed the formation of a 1T phase and the density of states (DOS) revealed that the 1T phase of VS2 is metallic in nature. After experimental and theoretical investigations of synthesized nanosheets, a VS2 electrode‐based in‐plane micro‐supercapacitor has been fabricated using a simple mask‐assisted printing technique. The fabricated device demonstrated excellent capacitance retention of 97.6% after 1000 cycles of cyclic voltammetry (CV) measurement at a 100 mV/s scan rate. The device also showed an excellent areal capacitance of 212.7 mF/cm2 and a high areal energy density of 10.63 µWh.cm‐2 at a high‐power density of 4.45 mW.cm‐2. This low‐cost and simple fabrication process can produce high‐performance in‐plane micro‐supercapacitor (MSC) devices.This article is protected by copyright. All rights reserved.

Transition metal dichalcogenides (TMDs) are highly efficient materials due to their vast applications in the domain of optoelectronics, photodetectors, catalysis, supercapacitors, and battery storage. Molybdenum disulfide (MoS2) is the most important TMD material due to the existence of fascinating optical, electronic, and chemical properties. Herein, we have synthesized MoS2 using a facile one-step hydrothermal technique resulting in low-cost 1T@2H MoS2 flower-like nanosheets and examined the structural, electronic, and optical properties. The field emission gun-scanning electron microscopy (FEG-SEM) images confirm the flower-like nanosheet morphology of the synthesized MoS2. Further, the Xray diffraction (XRD) peaks of MoS2 confirm the hexagonal phase with space group P63/mmc. The observed Transmission Electron Microscopy (TEM) image shows the formation of thin nanosheets of MoS2 while the crystal planes of MoS2 can be noticed from the High-Resolution Transmission Electron Microscopy (HRTEM) images. Also, an interplanar distance (d) of 0.62 nm has been observed from the HRTEM images of MoS2 nanosheets. The Raman spectrum confirms the vibrational modes corresponding to the 2H and 1T phase of MoS2 indicating the formation of a mixed phase in the structure. An excellent luminescent behavior has been observed from the photoluminescence (PL) plot. The electronic nature of the material has been evaluated from the Tauc plot and an optical band gap of 1.69 eV has been observed indicating the formation of a few layers of semiconducting MoS2. This rigorous study suggests the potential application of MoS2 in nanoelectronic devices.

Vanadium disulfide (VS2) is a prominent metallic member of transition metal dichalcogenides (TMDs) family and has already demonstrated its flair in energy storage device applications such as supercapacitors and batteries. In this work, we have synthesized hexagonal shape VS2 nanomaterial using a facile one step hydrothermal route and investigated the phase, morphology and structural properties of the material. The formation of phase has been confirmed from the X-ray diffraction (XRD) plot by correlating with the database of Joint Committee on Powder Diffraction Standards (JCPDS) 00-036-1139 of 1T VS2. Further, the crystalline behavior of VS2 nanomaterial can be seen from the high resolution transmission electron microscopy (HRTEM) measurement. Moreover, the morphology of the synthesized material is obtained from the field emission gun-scanning electron microscopy (FEG-SEM). Also, the characteristic Raman peaks of 1T VS2 at 140.3 cm -1 and 192.3 cm -1 have been observed from the Raman spectrum indicating the metallic behavior of synthesized material. The peak at 281.8 cm -1 is attributed to the in-plane vibrational mode (E2g 1 ) while the peak at 404.5 cm -1 represents the out-of-plane vibrational mode (A1g) of V-S bond. The Fourier transform infrared (FTIR) spectrum shows the V-S-V and V=S vibrational modes around 534 cm -1 and 982 cm -1 respectively. The study introduces a low cost, large scale, highly crystalline, and metallic VS2 nanomaterial with potential application for next generation supercapacitors and other energy storage devices.

Transition metal dichalcogenides (TMDs) are a class of two-dimensional (2D) materials which has several applications in the domain of optoelectronic devices, catalyst, sensor, and energy storage devices. Tungsten disulfide (WS2) is one of the important TMD material exhibiting semiconducting and metallic nature in the 2H and 1T phases respectively. Herein, we report a one-step hydrothermally synthesized large-scale and low-cost WS2 nanomaterial. Further, we have performed material characterization using X-ray diffraction (XRD), field emission gun-scanning electron microscopy (FEG-SEM), and transmission electron microscopy (TEM) to check the crystallinity, surface morphology, and shape of the nanomaterial. The XRD data matches very well with the mixed-phase 1T @ 2H of WS2. Also, the formation of crystal planes can be clearly seen from the high-resolution transmission electron microscopy (HRTEM) image of the synthesized material. Further, the surface morphology of as-grown WS2 nanomaterial has been investigated by field emission gunscanning electron microscopy (FEG-SEM) which shows the nanosheet-like morphology. Moreover, Raman spectroscopy has been done to check the presence of vibrational modes of the synthesized WS2. The Raman peaks were observed at 348.15 cm-1(E1 2g) and 414.18 cm-1 (A1g) corresponding to the in-plane vibrational mode and out-of-plane vibrational mode of 2H WS2. In addition, Raman peaks corresponding to the 1T phase of WS2 have also been obtained. This rigorous study on WS2 nanomaterial suggests its usefulness in energy storage applications such as supercapacitors, photocatalysis, and electrochemical sensors.