Photocatalytic Oxidation of Phenolic Compounds by Using a Carbon Nanotube-Titanium Dioxide Composite Catalyst

作者：Silva Claudia Gomes; Faria Joaquim Luis^*

来源：Chemsuschem, 2010, 3(5): 609-618.

DOI：10.1002/cssc.200900262

• Composites
• heterogeneous catalysis
• nanotubes
• photochemistry
• titanium

A nanostructured multiwalled carbon nanotube (CNT) and titanium dioxide composite Catalyst is prepared by a modified acid-catalyzed sol-gel method: Pure anatase TiO(2) and the CNT-TiO(2) composite are tested in the photocatalytic degradation of four para-substituted phenols: 4-chlorophenol, 4-aminophenol, 4-hydroxybenzoic acid and 4-nitrophenol. The effect of several operational parameters on the photoefficiency of the composite catalyst is studied by using 4-chlorophenol as model compound, namely catalyst loading, pH of the medium, hydrogen peroxide concentration, substrate concentration. A relationship between the Hammett constant of each para-substituted phenolic compound and its degradability by the photocatalysts is found. The effect of the carbon phase in the catalyst is ascribed to its photosensitizer action. A clear beneficial effect is observed for the degradation of 4-aminophenol and 4-chlorophenol. For the molecules with stronger electron-withdrawing (deactivating) groups, such as 4-hydroxybenzoic acid and 4-nitrophenol, no synergy effect is observed.

• 出版日期2010