E. Kumar

Lanthanum vanadate (LaVO ₄ ) nanoparticles and PANI–LaVO ₄ nanocomposites with varying LaVO ₄ loadings (2, 4 and 6 wt%) were synthesized and systematically investigated for supercapacitor applications.

Zirconium dioxide nanoparticles have been synthesized by microwave assisted solution method. The prepared nanoparticle have been characterized by powder X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy, ultraviolet- diffuse reflectance spectra, thermo gravimetric-differential thermal analysis and also evaluated for their antibacterial activity against bacterial strains. XRD pattern showed the prepared ZrO2 nanoparticles having monoclinic structure which shows the average crystalline size around 20 nm. SEM image showed the particles are spherical shape with agglomeration due to the intermolecular attraction for small particle size. From the UV-DRS,the energy band gap has found to be 4.9 eV. The results of antibacterial activity showed that the nanocrystalline zirconium dioxide had an important inhibitory activity against pseudomonas arginosa. Photocatalytic degradation of methylene blue dye in the presence of ZrO2 nanoparticle under sunlight has been investigated at various times. The 75 % of methylene blue dye has been degraded at 140 min of sunlight irradiation. The photocatalytic activity of catalyst has been high for 40 mg/50 mL sample concentration.

This paper explains the details on the preparation of polyaniline/CeO2 (10 wt %) nanocomposites using the method of in situ polymerization. The formation of PANI/CeO2 nanocomposites were proposed via oxidation of aniline and reduction of CeO2, respectively. The effect of CeO2 concentration on AC conductivity, morphological, optical and structural properties of the prepared PANI/CeO2 nanocomposites material were examined. The structural studies show the presence of CeO2 nanoparticles were occurred in PANI of nanocomposites. The average grain size of PANI/CeO2 nanocomposites varied with increasing and decreasing concentration due to the process of nucleation during the polymerization. The average particle grain sizes were measured from HRTEM. The morphology analysis was carried out from SEM. The UV absorption spectrum showed that the absorption peak of CeO2 nanoparticle at 341 nm, shifted to lower wavelength side, the nanocomposite absorption peaks at about 324, 368 and 858 nm was confirmed by the formation of PANI/CeO2 nanocomposites. The electronic structure of the band gap of the nanocomposite materials were calculated using ultraviolet visible absorption spectrum. The band gap energy of nanocomposite is 3.36 eV. The FTIR spectrum clearly showed the strong presence of CeO2 nanoparticles in PANI chain. The AC conductivity varied with varying the temperature and depends on the concentration due to the formation of PANI/CeO2 nanocomposite.

Journal of Nano- and Electronic Physics. Scientific journal. ISSN: 2077-6772. Journal abbreviation: J. Nano- Electron. Phys. No page charges. All articles are freely available on-line. Issued 4 times per year. Publisher: Sumy State University. (Sumy, Ukraine)