Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (07): 1751-1756.doi: 10.3866/PKU.WHXB20110701

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Effects of Surface Areas and Adsorption Strength on the Photoactivity and Decomposition Kinetics of Acid Red 27 over TiO2-Coated/Activated Carbon Composites

LI You-Ji, CHEN Wei, LI Lei-Yong   

  1. College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, Hunan Province, P. R. China
  • Received:2010-12-16 Revised:2011-04-26 Published:2011-06-28
  • Contact: LI You-Ji
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (50802034) and Natural Science Foundation of Hunan Province, China (09JJ6101).


TiO2-coated/activated carbon composites (TCS) were prepared by supercritical pretreatment and sol-gel processing. The prepared TCS were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption analysis. The photocatalytic performances of the composites were evaluated by the decolorization of an acid red 27 solution. The results show that the TCS have higher photocatalytic activity than bare TiO2 because of the smaller crystalline size of TiO2 and the higher amount of adsorbed acid red 27 as well as hydroxyl radicals. The photocatalytic activity of TCS increased and then decreased with an increase in surface area. The kinetic behavior of the photocatalytic degradation of acid red 27 over various composites is described in terms of a modified Langmuir-Hinshelwood model. The kinetic results clearly indicate differences in the photocatalytic activity of TCS, which is mainly attributed to interactions between the surface areas and the adsorption strength. TCS3 gave the highest photocatalytic activity with an optimal adsorption strength resulting from its moderate surface areas.

Key words: Photocatalysis, Titanium dioxide, Carbon, Supercriticalness, Sol-gel, Kinetics