Assembling of Composite of Ag/TiO2/Eu-MCM with Enhanced Photocatalytic Activity

Abstract

Ag/TiO2/Eu-MCM composite was prepared by a nanofilm of silver coating on a nanofilm of anatase TiO2­assembled onto the internal and external pore surface of a hierarchical micro/meso/macroporous molecular sieve Eu-MCM. The composites Ag/TiO2/Eu-MCM exhibited significant photocatalytic characteristics with more than four times higher UV-Vis-induced catalytic degradation for phenol than that of pure TiO2. The result is attributed to the composites possess vast specific surface areas, big pore width in favor of mass transfer, strong absorbance of nanofilm silver to UV-Vis light, rapid photoelectron transfer from excited nanofilm of TiO2to silver nanofilm, and reduction of the recombination probability of hole and photoelectron. There exists an excellent linear correlation with a correlation coefficient 0.979 between photocatalysis and fluorescence of the composite. A photocatalytic intermediate benzoquinone was measured using HPLC techniques during the process of photocatalytic degradation phenol under a weak UV-Vis radiation condition that indicated organic phenol was first oxidized into benzoquinone and finally degraded into inorganic species of carbon dioxide and water.