Efficient catalytic activity of BiVO4 nanostructures by crystal facet regulation for environmental remediation.

Controlled growth of BiVO4 nanostructures along (121) and (040) crystal facets plays a crucial role in enhancing their catalytic performance. In this regard, the visible light active photocatalyst BiVO4 was synthesized concerning the effect of pH and surfactants by hydrothermal method. The morphology and size of BiVO4 are strongly dependent on the concentration of H+ and Bi3+ in the reaction system while varying the pH. Further, the significant role of cationic surfactant for obtaining the morphology of the spherical nanoparticles of BiVO4 powders with size 55 nm was analyzed. Adsorption behavior of as-synthesized samples was investigated through Langmuir isotherm model. The catalytic performance of BiVO4 photocatalyst with the degradation efficiency of 98.79% and 15.58% over the methylene blue (MB) and methyl orange (MO) dyes were noticed within 60 min of light irradiation respectively. The enhanced and declined catalytic activity was well correlated with the surface charge of BiVO4 photocatalyst towards the MB and MO dyes respectively. Further, the photocatalytic activity of mixed anionic and cationic dyes was performed. The degradation pathway of MB dye was analyzed by LC-MS for the identification of intermediate products. From the obtained results, the proposed possible photocatalytic mechanism reported.

Synthesis and characterization of a new organic nonlinear optical crystal: L-phenylalaninium maleate.

l-Phenylalaninium maleate (abbreviated as LPM) chemical formula C(9)H(12)NO(2)(+).C(4)H(3)O(4)(-), a new organic nonlinear optical crystal was grown by slow evaporation technique. Transparent needle shaped crystal of dimensions 7mmx1mmx0.5mm was obtained. Single crystals of LPM have been subjected to X-ray diffraction analysis to estimate the lattice parameters and the space group. The powder X-ray diffractogram of the crystal has been recorded and the reflections from various planes are identified. The XRD studies confirm the crystalline nature. The qualitative analysis on the crystal has been carried out using Fourier transform infrared (FTIR) and Fourier transform Raman (FTRaman) spectral measurements. The presence of hydrogen and carbon in the grown crystal was confirmed by using proton and carbon nuclear magnetic resonance (NMR) spectral analyses. Optical behaviour of the crystal was investigated using UV-vis spectroscopy. The thermal stability of the crystal was analysed with the aid of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The nonlinear optical (NLO) property of the crystal was tested by Nd:YAG laser source.