title: ZnO-based hollow microspheres: biopolymer-assisted assemblies from ZnO nanorods.
abstract: Many efforts have been made in fabricating three-dimensional (3D) ordered zinc oxide (ZnO) nanostructures due to their growing applications in separations, sensors, catalysis, bioscience, and photonics. Here, we developed a new synthetic route to 3D ZnO-based hollow microspheres by a facile solution-based method through a water-soluble biopolymer (sodium alginate) assisted assembly from ZnO nanorods. The products were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, and X-ray photoelectron spectroscopy. Raman and photoluminescence spectra of the ZnO-based hollow microspheres were obtained at room temperature to investigate their optical properties. The hollow microspheres exhibit exciting emission features with a wide band covering nearly all the visible region. The calculated CIE (Commission Internationale d'Eclairage) coordinates are 0.24 and 0.31, which fall at the edge of the white region (the 1931 CIE diagram). A possible growth mechanism of the 3D ZnO superstructures based on typical biopolymer-crystal interactions in aqueous solution is tentatively proposed, which might be really interesting because of the participation of the biopolymer. The results show that this biopolymer-directed crystal growth and mediated self-assembly of nanocrystals may provide promising routes to rational synthesis of various ordered inorganic and inorganic-organic hybrid materials with complex form and structural specialization.
authors.affiliation: Key Laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, and Graduate School of the Chinese Academy of Sciences, Changchun 130022, P. R. China.
authors.forename: Shuyan
authors.initials: S
authors.lastname: Gao
authors.forename: Hongjie
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Wang
authors.forename: Ruiping
authors.initials: R
authors.lastname: Deng
authors.forename: Dehui
authors.initials: D
authors.lastname: Sun
authors.forename: Guoli
authors.initials: G
authors.lastname: Zheng
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D008863:Microspheres; D043942:Nanotubes / Q000737:chemistry*; D010316:Particle Size; D016062:Porosity; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D001704:Biopolymers; D015034:Zinc Oxide