In this work, WO 3 nanopowder was synthesized by an acidic co-precipitation method using sodium tungstate, nitric acid, and distilled water as precursors, while molybdenum disulfide (MoS 2 )/tungsten trioxide (WO 3 ) nanocomposite was prepared by exfoliation of MoS 2 in WO 3 at different concentrations of MoS 2 on WO 3 . All materials were analysed for their structural characteristics using X-ray diffraction (XRD) spectra. The XRD spectra confirm the formation of prepared samples. The morphology of the nanocomposites was investigated by field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). FESEM and HRTEM show that the addition of 2% MoS 2 has an insignificant effect on the morphology of WO 3 but when the MoS 2 concentration is increased to 4%, the particles' edges agglomerate and combine to create layered nanostructures that resemble flowers and join together to form a sphere. The electrochemical performance of all prepared samples was investigated using charge/discharge, chronoamperometry, and cyclic voltammetry. The electrochemical test results show that the electrochemical properties increase after the addition of MoS 2 in WO 3 due to the large active surface area. At ±1.5 V operating voltage, The electrochromic and optical properties of the prepared thin films were investigated using UV/Vis spectroscopy. The MSW2 nanocomposite exhibits the highest optical transmittance of 84% in the bleached state and 25% in the coloured state with a colouration efficiency of 67 cm 2 C À1 . The MSW2 nanocomposite retains a 97% colouration efficiency after 100 cycles. The electrochromic studies show that MoS 2 /WO 3 nanocomposites exhibit good results at low MoS 2 contents (ie, up to 2%). When the proportion of MoS 2 in WO 3 is increased (above 2%), the electrochromic performance decreases due to the deterioration of the transmittance (T%) of the nanocomposite.

In this present work, we synthesized WO3-SnO2 and Au doped WO3-SnO2 nanocomposite by hydrothermal method. The optical characterization has been done by UV/Vis spectroscopy to determine the band gap of pure and gold (Au) doped WO3-SnO2. Fourier transformed Infra red (FTIR) spectroscopy has been used to confirm the chemical bonding between Au and WO3-SnO2 nanocomposite. The X-ray Diffraction (XRD) technique was used to study the structural aspects of prepared materials. Field Emission Scanning Electron Microscopy (FESEM) has been used to investigate morphological characteristics of as prepared nanocomposite. The doping of Au was further confirmed by Energy-Dispersive X-ray spectroscopy (EDS) technique. The sensing properties have been studied from the I-V measurement of WO3-SnO2/Au nanocomposite for Benzene. The sensing parameters such as sensitivity (response), operating temperature and response and recovery time were calculated for benzene vapors.

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We report the detailed investigation of tungsten disulfide (WS2) wrapped tungsten trioxide (WO3) nanocomposites as electrode materials for electrochromic devices. The WS2/WO3 nanocomposite was prepared by exfoliation of WS2 in WO3, where WO3 was prepared by acidic co-precipitation technique. X-ray diffraction spectra were used to study the structural properties of the prepared materials. The results show that agglomeration due to pinning of grain boundaries by WS2 leads to an increase in the crystallite size of the nanocomposites, confirming the formation of WS2/WO3. Field-emission scanning electron microscopy and high-resolution tunnelling electron microscpy were used to study the nanocomposites morphology. The results show that the relative distribution of nanoparticles is more uniform compared to WO3 after the addition of WS2. The shape of WO3 changes from spherical to square nanosheets with good dispersion. The electrochemical properties of the prepared samples were investigated by chronoamperometry, charge/discharge ,and cyclic voltammetry. The lower peak separation between oxidation and reduction resulted from the fact that the peaks of the anodic and cathodic current densities of the nanocomposite (WS2/WO3) were shifted more to higher and lower potentials, respectively. This suggests faster charge transfer kinetics. UV/Vis spectroscopy was used to investigate the electrochromic and optical properties of the fabricated ECDs. The WS2/WO3-based ECDs exhibit a high colouring efficiency of 61 cm2C-1. The study shows that ECDs based on WS2/WO3 exhibit better electrochromic performance compared to WO3 ECDs