title: ZnO nanoparticles immobilized on flaky layered double hydroxides as photocatalysts with enhanced adsorptivity for removal of acid red G.
abstract: Flaky layered double hydroxides (FLDH) composed of cross-linked nanoflakes were prepared by the reconstruction of their oxides in alkali solution. The effect of reconstruction temperatures on the physicochemical properties was investigated. FLDH with a specific surface area of as high as 217 m(2)/g was obtained at a reconstruction temperature of 6 °C, and its derived flaky mixed metal oxides (FMMO) had a specific surface area of 249 m(2)/g. The ZnO nanoparticles were homogeneously deposited on the surface of the FLDH by coprecipitation. After calcination at 500 °C for 2 h, the ZnO-coated FLDH was transformed into ZnO-coated flaky mixed metal oxides (FMMO). The powders were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscope, N(2) adsorption-desorption isotherm, UV-vis diffuse reflectance spectroscopy, and Fourier transform infrared spectroscopy. In the presence of FLDH as a support, the ZnO nanoparticles were of about 10 nm in size and showed higher photocatalytic decomposition of acid red G than bare ZnO powder prepared under similar experimental conditions. It should be noted that the ZnO-coated FMMO combined excellent adsorption with photocatalytic activity. The flaky structure of mixed metal oxides appears to play important roles in the adsorption and photodecomposition process.
authors.affiliation: State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, MOE Donghua University, Shanghai 201620, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhi
authors.forename: Yaogang
authors.initials: Y
authors.lastname: Li
authors.forename: Qinghong
authors.initials: Q
authors.lastname: Zhang
authors.forename: Hongzhi
authors.initials: H
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D002384:Catalysis; D053768:Metal Nanoparticles; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010777:Photochemistry; D012235:Rhodamines / Q000737:chemistry / Q000302:isolation & purification*; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D012235:Rhodamines; C022027:lissamine rhodamine B; D015034:Zinc Oxide