ZnO nanoparticles immobilized on flaky layered double hydroxides as photocatalysts with enhanced adsorptivity for removal of acid red G

Langmuir. 2010 Oct 5;26(19):15546-53. doi: 10.1021/la1019313.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Catalysis
  • Metal Nanoparticles*
  • Microscopy, Electron, Scanning
  • Microscopy, Electron, Transmission
  • Photochemistry
  • Rhodamines / chemistry
  • Rhodamines / isolation & purification*
  • Zinc Oxide / chemistry*

Substances

  • Rhodamines
  • lissamine rhodamine B
  • Zinc Oxide