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Dried plum-like ZnO assemblies consisting ZnO nanoparticles were synthesized by an ultrasonic spray pyrolysis method (USP). ZnO assemblies were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS) and field-emission transmission electron microscopy (TEM). The results show the size of ZnO assemblies is in the range of 300–870 nm, and that of ZnO nanoparticles is from 33 nm to 39 nm. The microstructure and size of ZnO assemblies were successfully controlled by the concentration of the precursor solution. [ABSTRACT FROM AUTHOR]

ZnO nanoparticles were synthesized in a horizontal three zones furnace at 500 °C using different zinc nitrate hexahydrate concentrations (0.01 M, 0.1 M, and 1.0 M) as a reactive precursor solution by air assisted Ultrasonic Spray Pyrolysis (USP) method. The physico-chemical, structural and functional properties of synthesized ZnO nanoparticles have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), high resolution transmission electron microscopy (HRTEM), Brunauer, Emmett and Teller (BET) method, UV–vis spectroscopy and photoluminescence (PL) measurements. Also, the photocatalytic activities of ZnO synthesized from different precursor concentrations were evaluated by removal rate of methyleneblue (MB) under UV irradiation (365 nm) at room temperature. SEM revealed two types of ZnO nanoparticles: a quasi-spherical, desert-rose like shape of the secondary particles, which does not change significantly with the increasing of precursor solution concentration as well as some content of the broken spheres. Increasing the precursor solution concentration leads to the increase in the average size of ZnO secondary particles from 248 ± 73 to 920 ± 190 nm, XRD reveals the similar tendency for the crystallite size which changes from 23 ± 4 to 55 ± 12 nm in the analyzed region. HRTEM implies the secondary particles are with hierarchical structure composed of primary nanosized subunits. The PL spectra imply a typical broad peak of wavelength centered in the visible region exhibiting the corresponding red-shift with the increase of solution concentration: 560, 583 and 586 nm for the 0.01, 0.1 and 1.0 M solution, respectively. The reported results showed the photocatalytic efficiency of ZnO nanoparticles was enhanced by increased precursor concentration. [ABSTRACT FROM AUTHOR]

Abstract: Superparamagnetic nanocomposite particles prepared by the ultrasonic spray pyrolysis were used in localized hyperthermia therapy, one of the many therapy options for cancer treatment. The primary particle size of the Fe2O3/MgO nanocomposite particles prepared at 800°C was approximately 10nm. The particles show superparamagnetic properties with a blocking temperature of −148°C. Heat generated by an alternating magnetic field of 60Oe increases the tissue temperature to 42.5°C after 125s. [Copyright &y& Elsevier]