TiO2/MgAl layered double hydroxides mechanical mixtures as efficient photocatalysts in phenol degradation

• DOI: 10.1016/j.jpcs.2011.03.017
• Publication Date: 2011-05-12T11:23:27Z
• Authors: Silvia P. Paredes; Miguel A. Valenzuela; Geolar Fetter; Sergio O. Flores
• Keywords: Layered double hydroxides; Hydrotalcite; Physisorption

Abstract MgAl layered double hydroxides (MgAl LDH) were synthesized by the sol–gel method using ultrasound irradiation in the crystallization step. The interlayer anions were nitrate and acetylacetonate-ethoxide. The solids were characterized by XRD, N 2 -physisorption and TEM. TiO 2 /MgAl LDH mixtures were prepared by mixing the MgAl LDH (as prepared) or the calcined sample with TiO 2 (Aldrich, 99.9% anatase) in different weight ratios. Photocatalytic activities of the TiO 2 /MgAl LDH mixtures were evaluated through the degradation of phenol as model pollutant. TiO 2 /MgAl LDH mixture (1:1) was more photocatalytically active for the degradation of phenol than pure TiO 2 . The synergy effect was attributed to a higher production of • OH radicals, which were formed from the structural hydroxides. Also, the hydrotalcite phase enhanced the phenol adsorption and transfer to the TiO 2 sites where the phenol was photocatalytically degradated.