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PVDF-HFP/BaTiO 3 /GQDs polymer nanocomposite films with good flexibility and high dielectric constant (ϵ) at low frequency were prepared via solution casting technique. Different compositions of BaTiO 3 (non-conducting ceramic nanofiller) and Graphene quantum dots (GQDs) (conducting nanofiller) utilized as co-filler were embedded in poly (vinylidene fluoride-co-hexafluoroethylene) (PVDF-HFP) polymer matrix. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning electron microscopy (SEM) techniques were employed to characterize the prepared nanocomposite films. The mechanical properties of PVDF-HFP/BaTiO 3 /GQDs nanocomposite films were also investigated. Dielectric properties of nanocomposite films such as dielectric constant (ϵ), dielectric loss (tanδ) and AC conductivity ( σ ac ) were also determined as a function of frequency and temperature. Highest ϵ with relatively low tanδ obtained at low frequency for maximum temperature in all polymer nanocomposite films. The σ ac increases from lower (100 Hz) to higher frequency up to 100 kHz and drops to zero for the further increment of frequency. These results suggest that the PVDF-HFP/BaTiO 3 /GQDs nanocomposites are the most promising materials for energy storage applications., (Copyright © 2021 Elsevier Inc. All rights reserved.)

In the present work, the cost effective and facile hydrothermal synthesis technique was adopted to synthesize the copper (׀׀) oxide (CuO)-Nanoparticles (NPs). Physico-chemical characterization of the synthesized CuO-NPs was done by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-Vis), and scanning electron microscopy (SEM) analysis were carried out to study the structural, optical, and surface morphology of nanomaterial. XRD analysis revealed that the synthesized CuO-NPs had monoclinic structure and the average crystallite size is 20 nm. FTIR spectra indicate the vibrational bands of metal oxygen bonds (Cu-O). UV-visible absorption spectra were utilized to determine the energy band gap (E g ) of the CuO-NPs. In addition, we fabricated the chemiresistive sensor using synthesized CuO-NPs for detecting Volatile Organic Compounds (VOCs). These results demonstrate that CuO-NPs based chemiresistive sensor is ideal for qualitative detection of BTEX chemicals vapors (i.e. Benzene, Toluene, Ethylbenzene, and Xylene)., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Modifying the structures and doping are proven to be effective methods to tune the structural and electrical properties of g-C 3 N 4 quantum dots. Hence, in this study, tri-s-triazine and tri-nitro tri-s-triazine have been studied by functionalizing their edges with hydrogen. The H-functionalized tri-nitro tri-s-triazine quantum dot displays a buckled structure with a band gap of 1.988 eV, whereas the tri-s-triazine demonstrates a planner structure with a band gap of 1.636 eV. The obtained results have been compared with the previous results. The absorbance spectrum of H-functionalized trinitro tri-s-triazine falls under the visible region with a peak value of 488 nm, and the absorption spectrum of tri-s-triazine falls at 790 nm. The planarity of the tri-nitro tri-s-triazine structure is improved by doping the B atom in the N site, and the band gap of H-functionalized B doped tri-nitro tri-s-triazine is 1.143 eV. The absorbance spectrum of H-functionalized B doped tri-nitro tri-s-triazine is 508 nm. The reactivity of the structure is increased by doping B atoms, and it is confirmed by the electrophilicity index. Similarly, the H-functionalized B doped tri-s-triazine exhibits a band gap of 1.328 eV. Further, the tri-s-triazine structures are arranged in ternary form, and the properties are studied by increasing the number of B atoms in the tri-s-triazine rings. The outcome presents that the structures are planar, and band gap values are reduced further. Also, the reactivity of the sheets is increased, which is confirmed by the electrophilicity index. It is proposed that the sheets with a high reactivity can be used for the removal of hazardous ions and molecules from the industrial wastage., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)