Photocatalytic decomposition effect of erbium doped cerium oxide nanostructures driven by visible light irradiation: Investigation of cytotoxicity, antibacterial growth inhibition using catalyst.

Cerium (IV) oxide (CeO2) is the most accessible noble rare earth metal oxide for the excitation of the excitons by light-harvesting performance. The present work is focused on Erbium doped ceria nanoparticles that were beneficially obtained by hydrothermal method from cerium nitrate and Erbium nitrate as precursors for decomposition of Rhodamine-B (RhB) dye in the polluted waste water removed from the industries. Dye removal efficiency of the catalyst was found to be nearly ~94%. The structural phases, functional groups and the transitions are identified with the help of various techniques. XRD pattern determines the development of cubic phase with the particle size is 20 nm. Highly crystalline nature of as-synthesized nanomaterials with an average diameter of 35 nm was investigated by HRSEM. The crystalline size, shape and textural morphology, of the Erbium doped ceria nanostructures were analysed by HRTEM. Our results suggest, that the concentration of OH- ion determines the lattice constants and oxygen vacancy in the nanostructures which stimulate the probability of photocatalytic decomposition effect of organic pollutants, due to synergistic approach. In this context, both unhydrolyzed things and their swiftly drip from deceased or scratched cells with conceded membranes, even when the cells embrace some are outstanding attention. Although, the loss of viable cells also depends on epithelial cell dynamically conceal of numerous molar matrix.

Synthesis, Characterization and Humidity Sensing Properties of Nanocrystalline Composites of Sr1-xCoxMoO4 (x = 0, 0.3, 0.5, 0.7, 1).

The nanocrystalline strontium cobalt molybdate composites of Sr1-xCoxMoO4 (x = 0, 0.3, 0.5, 0.7, 1) were prepared by mixing various mole ratios (SrM-1, SrCM-2, SrCM-3, SrCM-4 and CoM-5) and investigated for their humidity sensing properties. The composites were characterized by thermal analysis (TG/DTA), X-ray powder diffraction (XRD), Fourier Transform-Infrared spectroscopy (FT-IR), Fourier Transform Raman (FT-Raman) spectroscopy, Scanning Electron Microscopy (SEM/EDAX), Transmission Electron Microscopy (TEM) and UV-Visible absorption spectroscopy. The composites were subjected to dc electrical conductivity based humidity sensing studies at room temperature. The resistance measurements as a function of relative humidity (RH) in the range of 5-98% were carried out and the sensitivity factor (Sf) were calculated. The SrM-1 is found to possess with the highest Sf of 33014 ± 660 and CoM-5 is found to possess a low Sf of 868 ± 43. The SrCM-2, SrCM-3 and SrCM-4 possessed the sensitivity factors (Sf) of 915 ± 45, 3713 ± 185 and 3390 ± 102 respectively.

Facile synthesis of heterostructured cerium oxide/yttrium oxide nanocomposite in UV light induced photocatalytic degradation and catalytic reduction: Synergistic effect of antimicrobial studies.

Ceria (CeO2) is an exciting alternative noble metal catalyst, because it has ability to release and absorb oxygen in the redox system, and function as an oxygen buffer. In this study, heterostructured catalysts consisting of CeO2/Y2O3 nanocomposites were successfully synthesized by hydrothermal method in the presence of sodium hydroxide as a reducing agent from cerium nitrate and yttrium nitrate as a precursor which was then evaluated for its photocatalytic activity in the degradation of Rhodamine B (RhB) synthetic dye. Scanning electron microscopy (SEM) imparts the surface morphology and size of the prepared sample. Elemental compositions and the purity of the nanoparticles are proved by energy dispersive X-ray Spectroscopy (EDX). CeO2/Y2O3 nanoparticles were made up of CeO and YO bonds which are confirmed by Fourier transform infrared spectroscopy (FTIR). Synthesis temperature and pressure, during hydrothermal reactions, plays a critical role in controlling the shape, size, oxygen vacancy concentration, and low temperature reducibility in CeO2 based nanocomposites. The lattice constants and oxygen vacancy concentrations of ceria nanoparticles also depend upon the concentration of hydroxide ion which leads to better morphology at low temperature and pressure. Hydrogenation of p-nitrophenol to p-aminophenol with a reducing agent is conveniently carried out in aqueous medium by using this binary metal oxide catalyst. Further, the photocatalytic performance of the synthesized nanoparticles was monitored by photocatalytic degradation of Rhodamine B synthetic dye under UV light irradiation. To get maximum photocatalytic degradation (PCD) efficiency, we have used H2O2 for the generation of excess reactive oxygen species (ROS). In addition, the antibacterial activity of nanoparticles against bacteria was also examined. The observed antibacterial activity results are comparable with the results obtained using the standard antibiotic.

Photocatalytic degradation effect of malachite green and catalytic hydrogenation by UV-illuminated CeO2/CdO multilayered nanoplatelet arrays: Investigation of antifungal and antimicrobial activities.

CeO2/CdO multi-layered nanoplatelet arrays have been synthesized by sol-gel method at two different temperatures using Citrus limonum fruit extract and the effect of particle size on the photocatalytic performance is studied. The particle size and phases was analysed by X-ray diffraction pattern (XRD) which brought out the formation of cubic phase in the synthesized samples. Field Emission Scanning electron microscopy (FESEM) revealed the surface morphology and made up of cumulative form of platelet shaped arrays with an average size of 10nm. The elemental composition and the purity of the nanomaterials were confirmed by Energy Dispersive X-ray spectroscopy (EDX). CeO2/CdO multilayered binary metal oxide nanoplatelet arrays were formed which was further explored with Fourier transform infrared spectroscopy (FTIR), it reveals that the nanocomposites contain CeO and CdO bonds. Determination of the direct and indirect bandgap energy of the nanoplatelet arrays was carried out by UV-Vis-DRS studies. In MG degradation, both the hole (h+) and hydroxyl radical (OH) played a major role than the superoxide radical (O2-). Possible photo degradation mechanisms are proposed and discussed in this article. CeO2/CdO multi-layered nanoplatelet arrays showed antibacterial activity and among the tested ones, it showed better growth inhibition towards P. aeruginosa MTCC73. Thus, this greener synthetic procedure was a highly effective method due to low-cost, highly effective UV light responsive material for environmental safety.

Photocatalytic activity of binary metal oxide nanocomposites of CeO2/CdO nanospheres: Investigation of optical and antimicrobial activity.

We report the synthesis of high quality CeO2-CdO binary metal oxide nanocomposites were synthesized by a simple chemical precipitation and hydrothermal method. Cerium nitrate and cadmium nitrate were used as precursors. Composition, structure and morphology of the nanocomposites were analyzed by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). XRD pattern proves that the final product has cubic phase and the particle size diameter of the nanocomposites are 27nm, XRD results also indicated that the crystalline properties of the nanocomposite were improved without affecting the parent lattice, FESEM analysis indicates that the product is composed of spherical particles in clusters. The morphological and optical properties of CeO2-CdO nanosamples were characterized by HRTEM and DRS spectroscopy. The IR results showed high purity of products and indicated that the nanocomposites are made up of CeO2 and CdO bonds. Absorption spectra exhibited an upward shift in characteristic peaks caused by the addition of transition metal oxide, suggesting that crystallinity of both the metal oxide is improved due to specific doping level. TGA plots further confirmed the purity and stability of nanomaterials prepared. Hence the nanocomposite has cubic crystal lattice and form a homogeneous solid structure. From the result, Cd(2+) ions are embedded in the cubic crystal lattice of ceria. The growth rate increases which are ascribed to the cationic doping with a lower valence cation. Ce-Cd binary metal oxide nanocomposites showed antibacterial activity, it showed the better growth inhibition towards p.aeruginosa. Exploit of photodegradation and photocatalytic activity of large scale synthesis of CeO2-CdO binary metal oxide nanocomposites was reported.

Synthesis, growth, structural and optical studies of organic nonlinear optical material--piperazine-1,4-diium bis 2,4,6-trinitrophenolate.

Piperazine-1,4-diium bis 2,4,6-trinitrophenolate is one of the useful organic materials with nonlinear optical (NLO) and pharmaceutical applications. The material was grown by slow evaporation solution growth method at room temperature. The crystal system and lattice parameters were identified by single crystal XRD analysis. The grown material crystallizes in monoclinic system with P21/n space group. The main functional groups NH2, NO2, CN, CC, and phenolic 'O' atom were identified using FTIR analysis. The protons and carbons of grown crystal with various chemical environments were studied by 1H and 13C NMR spectroscopy to confirm the molecular structure. The optical properties of the crystal were studied by UV-vis-NIR spectroscopy and the transmission 100% range starts from 532 nm onwards. The optical band gap was measured as 2.63 eV from the plot of (αhν)2 versus hν. The thermal stability was detected at 304.1°C using TG-DTA analysis. The dielectric studies of the sample were carried out at different temperatures in the frequency range from 50 Hz to 5 MHz to establish the dielectric nature of the crystal. Photoconductivity measurements were carried out on the grown crystal. The Second Harmonic Generation (SHG) of the crystal was tested to confirm the nonlinear optical property.

Utilization of strontium added NiAl(2)O(4) composites for the detection of methanol vapors.

Strontium added NiAl(2)O(4) composites prepared by sol-gel technique was utilized for the detection of methanol vapors. X-ray diffraction, scanning electron microscopy (SEM), FT-IR spectroscopy and nitrogen adsorption/desorption isotherm at 77K was employed respectively to identify the structural phases, surface morphology, vibrational stretching frequencies and BET surface area of the composites. The composites were prepared with the molar ratios of Ni:Sr as (1.0:0.0, 0.8:0.2, 0.6:0.4, 0.4:0.6, 0.2:0.8, 0.0:1.0) keeping the aluminum molar ratio as constant for all the compositions and were labeled as NiSA1, NiSA2, NiSA3, NiSA4, NiSA5 and NiSA6, respectively. The samples sintered at 900 degrees C for 5 h were subjected to dc resistance measurements in the temperature range of 30-250 degrees C to study the methanol vapor detection characteristics. The results revealed that the sensitivity in detecting methanol vapor increased with increase in temperature up to 175 degrees C for the composites NiSA1 and NiSA6 while for the other composites up to 150 degrees C and thereafter decreased. The sensitivity increased with increase in methanol concentration from 100 to 5000 ppm at 150 degrees C. Among the different composites NiSA5 showed the best sensitivity to methanol detection at an operating temperature of 150 degrees C.