RESEARCH PAPER Triblock copolymer-templated synthesis of porous TiO 2 and its photocatalytic activity Cheewita Suwanchawalit • Sumpun Wongnawa Received: 3 September 2009 / Accepted: 12 February 2010 / Published online: 27 February 2010 Ó Springer Science+Business Media B.V. 2010 Abstract Mixed amorphous and anatase-type titania particles were synthesized using non-ionic triblock copolymer as surfactant template and TiOSO 4 as inorganic precursor through sol–gel process. The as- prepared materials were characterized by X-ray diffraction spectroscopy, scanning and transmission electron microscopy, specific surface area, Fourier- transformed infrared spectroscopy, and diffuse reflec- tance ultraviolet–visible spectroscopy. The template material could be easily removed by extracting with dichloromethane and was confirmed by infrared spectroscopy. X-ray diffraction pattern reveals the crystalline part of as-prepared product as a framework of anatase phase. From the N 2 adsorption–desorption analysis, the as-prepared sample has a surface area of 301 m 2 /g with pore size distribution narrowly cen- tered around 6 nm. The photodegradation of indigo carmine including kinetics, effect of pH, and recycla- bility of the product were investigated. The photocat- alytic results showed that the as-synthesized titania could efficiently degrade indigo carmine under ultra- violet irradiation and showed higher photocatalytic activity than the commercial Degussa P25–TiO 2 . Keywords Titanium dioxide  Sol–gel process  Non-ionic surfactant  Indigo carmine  Dye decolorization  Catalyst  Environmental remediation Introduction Photocatalytic oxidation with semiconducting mate- rials has been accepted as a promising method for purification and remediation of polluted water and air. Of the semiconducting materials employed, TiO 2 is the most prevailing one because of its high photosen- sitivity, non-toxicity, easy availability, environmen- tally friendly, and low cost (Litter 1999; Fox and Dulay 1993; Legrini et al. 1993; Carp et al. 2004). The efficiency of the commercial Degussa P-25 TiO 2 in the treatment of exhaust gas and waste water contaminated with organic and inorganic pollutants has been fully proved. In order to maximize photo- catalytic activity, TiO 2 particles should be small enough to offer a high number of active sizes per unit mass (Zhang et al. 1998). Therefore, in most cases, the samples are ultrafine powders and have large surface area. However, their effective applications are C. Suwanchawalit  S. Wongnawa (&) Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand e-mail: sumpun.w@psu.ac.th Present Address: C. Suwanchawalit Department of Chemistry, Faculty of Science, Silpakorn University, Sanam Chandra Palace Campus, Nakornpatom 73000, Thailand 123 J Nanopart Res (2010) 12:2895–2906 DOI 10.1007/s11051-010-9880-y