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Uniform dispersion of Pd nanostructures supported on hydrothermally synthesized bimetal oxides on Ni foam substrate was successfully achieved by a simple electrochemical approach. The incorporated metal oxides provide excellent support and active surface area, which lead to superior electro-catalytic performance towards ethanol sensing applications. The synthesized nanocomposite materials were characterized by XRD, FE-SEM, HR-TEM, and EIS techniques, and their electrochemical behaviour was investigated using cyclic voltammetry and chronoamperometry techniques. The proposed sensor demonstrated excellent catalytic activity, high reproducibility, and long-term stability for ethanol electro-oxidation. In addition, the fabricated sensor displayed high sensitivity of 1277 μA mM−1 cm−2 in the concentration range from 0.1 to 2.1 mM with a limit of detection 0.7 μM. Enhancement in electro-catalytic activity is mainly due to the induced synergistic effect of metal oxide nanocomposite support that stabilizes the Pd NPs through the Pd–HO bond by the transfer of an electron to the PdNPs. This study paves the way for designing and constructing effective electro-catalysts that can be used in the real-time analysis of alcohol sensing. [ABSTRACT FROM AUTHOR]

Barium titanate nanoparticles were synthesized via a low temperature sol-gel technique using acetylacetone as a chelating agent. The X-ray diffraction pattern confirmed the formation of tetragonal perovskite structure of the material. The average crystallite size was found to be 49 nm using the Debye-Scherrer method. The Williamson–Hall plot was drawn for evaluating the micro-strain and crystallite size. Raman spectroscopic features typical for the tetragonal phase were identified for Barium titanate powder. In addition to these, an absorption band edge and an optical bandgap were found to be of 406 nm and 3.14 eV respectively. Barium titanate displays polychromatic luminescent peaks in UV -visible regions and it was attributed to the near-band-edge transition and defect states in the optical band gap of the perovskite structure. [ABSTRACT FROM AUTHOR]

Pure TiO2 and Cu doped TiO2 nanoparticles were prepared by a simple solution approach using hexamethylenetetramine as a chelating agent. The XRD analysis confirmed that the synthesized sample has a hexagonal wurtzite structure. Further, the average crystallite size of pure TiO2 and Cu doped TiO2 estimated from the Debye-Scherrer formula is found to be 10 nm and 9 nm respectively. In the Raman spectrum, the bands for the range 125–635 cm−1 ascertains the anatase crystal structure, while the shift in the position of the principal peak of the doped sample toward higher wavenumber indicates that the dopant may extend some defects and/or surface oxygen vacancies in the doped sample. From the photoluminescence spectrum polychromatic emissions are observed in the range 340–500 nm. The UV-Vis result showed that the absorption edge for Cu doped TiO2 extended to the visible region when compared to the pure TiO2 nanoparticles. The optical band gap of pure and Cu doped TiO2 nanoparticles is also found to be 3.06 eV and 2.92 eV, respectively. The observed reduced band gap can serve as a potential candidate for the degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

Light-induced photocatalytic degradation of ceftiofur sodium (CFS) has been assessed in the presence of plasmonic zinc oxide nanostructures (ZnONSTs), like, ZnO nanoparticles, ZnO nanorods (ZnONRs) and ZnO nanoflowers (ZnONFs). Silver nanoparticles (Ag NPs) loaded ZnO nanostructures (Ag-ZnONSTs) are obtained through seed-assisted chemical reaction followed by chemical reduction of silver. The surface modification of ZnO nanostructures by Ag NPs effectually altered their optical properties. Further, the surface plasmonic effect of Ag NPs facilitates visible light absorption by ZnONSTs and improved the photogenerated electron and hole separation, which makes the ZnONSTs a more active photocatalyst than TiO 2 (P25) nanoparticles. Especially, Ag-ZnONRs showed higher CFS oxidation rate constant (k' = 4.6 × 10−4 s−1) when compared to Ag-ZnONFs (k' = 2.8 × 10−4 s−1) and Ag-ZnONPs (k' = 2.5 × 10−4 s−1), owing to their high aspect ratio (60:1). The unidirectional transport of photogenerated charge carriers on the Ag-ZnONRs may be accountable for the observed high photocatalytic oxidation of CFS. The photocatalytic oxidation of CFS mainly proceeds through •OH radicals generated on the Ag-ZnONRs surface under light illumination. In addition, heterogeneous activation of peroxymonosulfate by Ag-ZnONRs accelerates the rate of photocatalytic mineralization of CFS. The quantification of oxidative radicals supports the proposed CFS oxidation mechanism. Stability studies of plasmonic Ag-ZnONSTs strongly suggests that it could be useful to clean large volume of pharmaceutical wastewater under direct solar light irradiation. [Display omitted] • Ag–ZnO nanorods, nanoflowers & nanoparticles were prepared by solvothermal method. • Colorless ceftiofur sodium was mineralized under Ag/ZnO UV–vis light illumination. • Ag-ZnONRs exhibited a 4-fold enhancement of CFS oxidation compared to P25 TiO 2 NPs. • Estimation of.•OH radicals was performed to understand rate of CFS oxidation. • 89% of CFS was mineralized in presence of Ag–ZnO/PMS at 6 h illumination. [ABSTRACT FROM AUTHOR]

A comparative investigation of the structural, optical, and magnetic properties of NiFe 2 O 4 (NFO) and ZnFe 2 O 4 (ZFO) spinel nanoparticles were synthesized by microwave combustion method. X-ray diffraction (XRD) showed that the ZFO spinel nanoparticles formed a cubic structure, but the NFO spinel nanoparticles formed with additional Fe 2 O 3 in them. The average crystallite size was observed to be in the range 16–20 nm. X-ray photoelectron spectroscopy (XPS) peak areas are often used to quantify the elemental compositions and oxidizing states of NFO and ZFO spinel surfaces. The appearance of FT-IR bands at around 548, 514 and 649 cm−1 were correlated to the Fe–O and Zn/Ni–O stretching modes of cubic NFO and ZFO structure. The direct band gap estimated using Kubelka–Munk (K–M) method to obtain by the NFO is 3.35 eV and ZFO is 2.13 eV respectively. The surface morphology revealed nanosized crystalline grains with agglomerate separated particles that are like spherical/non-spherical forms and fused grain boundaries. Magnetic measurements of NFO and ZFO spinel nanoparticles showed ferromagnetic behavior at room temperature. [ABSTRACT FROM AUTHOR]

Polyhydroxyalkanoates (PHAs) are storage granules found in bacteria that are essentially hydroxy fatty acid polyesters. PHA molecules appear in variety of structures, and amongst all types of PHAs, polyhydroxybutyrate (PHB) is used in versatile fields as it is a biodegradable, biocompatible, and ecologically safe thermoplastic. The unique physicochemical characteristics of these PHAs have made them applicable in nanotechnology, tissue engineering, and other biomedical applications. In this review, the optimization, extraction, and characterization of PHAs are described. Their production and application in nanotechnology are also portrayed in this review, and the precise and various production methods of PHA-based nanoparticles, such as emulsion solvent diffusion, nanoprecipitation, and dialysis are discussed. The characterization techniques such as UV-Vis, FTIR, SEM, Zeta Potential, and XRD are also elaborated. [ABSTRACT FROM AUTHOR]