Optical, photoconducting, thermal and anisotropic mechanical behaviours of Benzimidazolium salicylate single crystals

Protonated organic single crystals of Benzimidazolium salicylate (BSL) were successfully grown by the slow evaporation solution technique at room temperature. The crystal structure and lattice parameters of the as-grown single crystal have been identified and calculated by the powder X-ray diffraction (PXRD) method. Microanalysis has confirmed the elemental compositions and the Fourier transform infrared (FTIR) spectroscopy technique has revealed vibrations of the functional groups in these crystals. The optical band gap was calculated indicating that the as-grown crystal exhibits 75% of optical transparency in the 350–800 nm range. Fluorescence study has suggested the blue emission nature of the crystal. The thermal stability of the as-grown crystal has been elaborated from the thermogrativity differential thermo-analysis (TG-DTA) technique. Vickers hardness measurement has revealed the mechanically soft nature of the crystal, which is driven by the reverse indentation size effect (RISE) and shows an anisotropic behaviour. A linear increase of the photocurrent on illumination suggests the positive photoconductivity of the crystal. The third-order non-linear optical property characteristics, such as the absorption coefficient (β), the refractive index (n2) and the susceptibility (χ(3)) have been examined using the Z-scan technique

Photocatalytic degradation of metronidazole and methylene blue by PVA-assisted Bi2WO6–CdS nanocomposite film under visible light irradiation

Abstract The enhanced photocatalytic performance of nanocomposite is synthesized via the hydrothermal method and characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FT-IR), UV–visible diffuse reflectance spectroscopy (UV–Vis DRS) and photoluminescence spectroscopy (PL). Under visible light irradiation, PVA assisted Bi2WO6–CdS nanocomposite film displayed enhanced photocatalytic efficiency and inhibition of photocorrosion as compared with pure CdS, pure Bi2WO6 and Bi2WO6–CdS composite. The PVA assisted Bi2WO6–CdS composite film catalyst showed stable catalytic performance until seven successive runs with 92% of methylene blue(MB) degradation, and easy to recover after degradation of organic pollutant. PVA assisted Bi2WO6–CdS nanocomposite film has optimal band edge position for superior photocatalytic degradation. Furthermore, the trapping experiment was carried out using different scavenger for active species. Among the active species, OH· are the most responsive species which play a vital role in the degradation of metronidazole and MB.</jats:p