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[Display omitted] • Flower-like C-ZnO microspheres assembly from nanoneedles were prepared using carbon spheres as templates. • C-ZnO nanoneedle is single crystal with exposed nonpolar {1010} facets. • Doping ZnO with C results in the production of oxygen vacancies. • Flower-like C-ZnO microspheres exhibited high photoreactivity and excellent stability towards MO degradation. In this work, carbon spheres (CSs) derived from glucose by simple eco-friendly process were used to create a multiphase environment for precipitation reaction to obtain flower-like C-doped ZnO (C-ZnO) nanoneedles assembly. It was found that the presence of carbon spheres can affect the crystal orientation and morphology of ZnO. When the additive amount of carbon spheres was 13 wt%, one-dimensional (1D) needle-like single crystal C-doped ZnO were obtained, which exposed with higher proportion of nonpolar {1010} facets (51%) than that of pristine ZnO (46%), and C-Zn and C-O-Zn bonds were formed. Compared with pristine ZnO prepared by direct precipitation method (ZnO-DPM) without carbon spheres, carbon doped ZnO exhibited higher light absorption ability and smaller band gap width due to the formation of surface defects. The photocatalytic degradation rate of methyl orange over 13 %C-ZnO was 99.98% for 3 h under the irradiation of UV lamp (15 W), almost 1.3 times higher than that of pristine ZnO-DPM. Even after repeating use for 3 times, the degradation rate of methyl orange can be kept as high as 99%. The present study offers a new preparation method for high photoreactive ZnO with exposed nonpolar {1010} facets by precipitation reaction. [ABSTRACT FROM AUTHOR]

Abstract: Pd2+-doped ZnO nanotetrapods were prepared and studied for the humidity detection application. The humidity sensors developed were featured by combination of a quartz crystal microbalance (QCM) as a transducer and Pd2+-doped ZnO nanotetrapods as a sensing element. The ZnO nanotetrapods were synthesized by evaporating highly pure zinc pellets (99.999%) at 900°C in air and PdCl2 was doped on by traditional solution mixing process. Then the mixed solution distributed onto the electrode surfaces of the quartz crystal at room temperature. Pd2+-doped ZnO nanotetrapods were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The experimental results indicated that the response of the sensors varied with the different dosage PdCl2. Linear regression algorithm was used for evincing the highly linear behavior of the Pd2+-doped ZnO nanotetrapods sensor. In this humidity sensing system, the Pd2+-doped ZnO nanotetrapods sensing material coated on the gold electrode of QCM showed good sensitivity (∼74.24324Hz/%RH (relative humidity)), reproducibility, linearity (R 2 =−0.98834), short response and recovery time (less than 5s). [Copyright &y& Elsevier]

Abstract: Zinc oxide (ZnO) nanofibers were synthesized by atom layer deposition (ALD) using polyvinylpyrrolidone (PVP) fibers as template. It was found that the morphologies of ZnO nanofibers were the same as PVP nanofibers. By annealing treatment, the different morphologies of ZnO nanofibers could be formed with the decomposition of PVP nanofibers which were characterized by means of transmission electron microscopy (TEM) and room temperature Raman spectra. The crystal and the optical properties can be also improved. The photocatalytic activities of the as-growth ZnO samples were evaluated in the photocatalytic degradations of aqueous solutions of methyl orange at room temperature. ZnO nanofibers showed higher photocatalytic activity due to more surface-to-volume ratio. [Copyright &y& Elsevier]

The tube-brush-like ZnO nanostructures were synthesized by hydrothermal method using electrospinning polyvinylpyrrolidone (PVP) nanofibers as templates. The photocatalytic activity of as-grown samples was investigated by photo-degradation of Rhodamine B (RhB). The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV/visible absorption spectroscopy (UV–vis) and photoluminescence (PL) spectroscopy. It was found that the morphologies of the prepared ZnO were tube-brush-like nanostructures. With the grown time increasing, the crystal and the optical properties were improved. In the photocatalytic experiment, the tube-brush-like ZnO nanostructures photocatalytic activity was enhanced the degradation of RhB was up to 98% after 2 h of irradiation. The tube-brush-like ZnO nanostructures showed higher photocatalytic activity because of the special surface morphology. [ABSTRACT FROM AUTHOR]

Abstract: Vertically aligned ZnO nanowires (NWs) can be reconstructed on large scales by a solvent-evaporation-induced method. The morphologies of the nanowires are regulated by changing the concentration of the solution. Possible mechanism, which the compressive residual stresses and wires/wires self-attraction can be responsible for the surface reconstruction, is addressed. Furthermore, we compare the structural properties of ZnO nanowires before and after reconstructed. [ABSTRACT FROM AUTHOR]