Cite this: RSC Advances, 2013, 3, 14970 Received 5th April 2013, Accepted 26th June 2013 Facile and green release of template from mesostructured titania3 DOI: 10.1039/c3ra42981d www.rsc.org/advances Karine Assaker, a Be ´ne ´dicte Lebeau,* b Claire Marichal, b Ce ´dric Carteret, c Loı ¨c Vidal, b Marie-Jose ´ Ste ´be ´ a and Jean-Luc Blin* a Molecules of pluronic P123 template can be efficiently removed from the pores of mesostructured titania by water extraction at various temperatures from ambient to 100 uC. Such soft and green treatment leads to the formation of anatase nanocrystallites in the walls of the mesoporous titania solid even at room temperature. Recently, there has been a rapid growth in emerging areas such as nanotechnology, photonics and bioengineering, which require porous structures with well-defined structural, interfacial, compo- sitional and morphological properties. Ordered mesoporous materials are excellent candidates for such applications. As a matter of fact, they have tuneable pore sizes (2–30 nm), high specific surface areas (.800 m 2 g 21 ) and high pore volumes (.0.7 cm 3 g 21 ). 1,2 These characteristics afford their use for several potential applications in many fields such as adsorbents, catalysts, host matrixes for electronic and photonic devices, drug delivery and sensors. 3–7 The synthesis of these compounds combined the sol–gel chemistry and the use of assemblies of surfactant molecules as framework templates, therefore before developing the applications the surfactant has to be removed to release the porosity. To reach this goal different strategies have been developed such as calcination, solvent extraction, chemical oxidation, supercritical fluid extraction, etc. 8–15 These surfactant removal processes are usually intensive energy consumer, not environmentally friendly and sometimes they require specific devices and instrumentation. In addition it is often difficult to recover the surfactant for reuse. Moreover, in the case of non siliceous ordered mesoporous materials such as titania-based ones, it is difficult to obtain a stable mesostructure and the main challenge is to preserve the pore ordering upon surfactant removal. Amongst the different oxides, titania is of particular interests. As a matter of fact, TiO 2 is a semiconductor that has received considerable attention for applications in electronics, electrochemical systems, including photoelectrochemical solar cells, electrocatalysis, optoelectronic sensor devices and high performance photocatalytic films. 16–20 In almost all these applica- tions, the crystal structure, particle size, surface area and porosity of titania are important factors for the performance of these materials. In previous papers, we have reported a simple and effective route for synthesizing ordered mesoporous titania with a high surface area in short synthetic period (3 days). 21,22 Our approach was inspired by the evaporation-induced self assembly method and the liquid crystal templating pathway that can be employed for the synthesis of ordered silica mesoporous materials. The ordered titania mesoporous materials were prepared from non-ionic surfactant liquid crystals by a properly controlled sol–gel method via the liquid crystal templating mechanism (LCT). Precipitation of titania in the hybrid meso- phase was activated by a NH 3 treatment. The surfactant species in the channels are removed by ethanol extraction and calcination. The latter has also been used to transform the amorphous TiO 2 to anatase, which is generally recognized to be the most active phase for photocatalysis. In this paper we demonstrate that the triblock copolymer P123 (EO) 20 (PO) 70 (EO) 20 , employed as a structure- directing agent for the synthesis of the mesostructured TiO 2 , can be efficiently removed in an easy, mild, low cost and environmen- tally friendly way. Except the template removal step, ordered mesoporous titania has been prepared according to the procedure we have previously reported. 21,22 Here, to release the mesoporosity of the as-synthesized materials, the (EO) 20 (PO) 70 (EO) 20 molecules a SRSMC UMR 7565, Universite ´ de Lorraine, CNRS, F-54506 Vandoeuvre-le `s-Nancy cedex, BP 70239, France. E-mail: Jean-Luc.Blin@univ-lorraine.fr; Fax: (+)33 3 83 68 43 44 b Univ de Haute Alsace (UHA), CNRS, Equipe Mate ´riaux a ` Porosite ´Controˆle ´e (MPC), Institut de Science des Mate ´riaux de Mulhouse (IS2M), UMR 7361, ENSCMu, 3bis rue Alfred Werner, F-68093 Mulhouse cedex, France. E-mail: Benedicte.lebeau@uha.fr c LCPME UMR 7564, Universite ´ de Lorraine, CNRS, 405, rue de Vandoeuvre, F-54600 Villers-le `s-Nancy, France 3 Electronic supplementary information (ESI) available: Nitrogen adsorption– desorption isotherms and pore size distribution as a function of the surfactant extraction by water with time at room temperature (S1). TGA data of sample recovered after surfactant extraction by water during 5 h at room temperature (S2). Evolution of the infrared spectra as a function of the extraction time at room temperature (S3). 1 H decoupled 13 C MAS NMR spectra of as-synthesized ordered mesoporous titania (a) and silica (b) (S4). Specific surface area and the pore volume as a function of the surfactant extraction time by water at 80 uC (A) and 100 uC (B) (S5). XRD of the mesoporous titania obtained after surfactant extraction by water at 80 and 100 uC (S6). See DOI: 10.1039/c3ra42981d RSC Advances COMMUNICATION 14970 | RSC Adv., 2013, 3, 14970–14974 This journal is ß The Royal Society of Chemistry 2013