Fabrication of Three-Dimensionally Ordered Macro-/Mesoporous Titania Monoliths by a Dual-Templating Approach
- PDF / 303,546 Bytes
- 6 Pages / 432 x 648 pts Page_size
- 76 Downloads / 208 Views
Fabrication of Three-Dimensionally Ordered Macro-/Mesoporous Titania Monoliths by a Dual-Templating Approach Zhiyan Hu,1 Zhongjiong Hua,1 Shaohua Cai,1 Jianfeng Chen,1 Yushan Yan,2 and Lianbin Xu1,2,* 1 Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, China 2 Department of Chemical and Environmental Engineering, University of California at Riverside, Riverside, CA 92521 E-mail: [email protected] ABSTRACT Three-dimensionally ordered macro-/mesoporous (3DOM/m) TiO2 monoliths were fabricated by a dual-templating synthesis approach employing a combination of both colloidal crystal templating (hard-templating) and surfactant templating (soft-templating) techniques. Titania precursor, consisting of amphiphilic triblock copolymer Pluronic P123 as a mesoporestructure-directing agent and titanium tetraisopropoxide as a titanium source, was infiltrated into the void spaces of the poly(methyl methacrylate) (PMMA) colloidal crystal monolith. Subsequent thermal treatment produced 3DOM/m TiO2 monolith. The macropore walls of the prepared 3DOM/m TiO2 exhibit a well-defined mesoporous structure with narrow pore size distribution, and the mesopore walls are composed of nanocrystalline anatase TiO2. The material also shows a high surface area (171 m2/g), and large pore volume (0.402 cm3/g). INTRODUCTION Due to its unique physicochemical properties, titania (TiO2) has been extensively investigated for applications in photocatalysis, solar cells, electrochromic devices, and sensors [1]. The properties of TiO2 strongly depend on its phase composition, crystallinity, and microstructure [1, 2]. Ordered mesoporous TiO2 materials with a crystalline framework, high specific surface area and tailored pore structure are of much interest owing to their high reactivity, enhanced adsorption and sensing ability, and molecular sieving effect. The surfactant templating method through cooperative self-assembly of titania and surfactant has been well established for the fabrication of ordered mesoporous TiO2 materials [3-5]. Recently, TiO2 materials with hierarchically macro-/mesoporous structure have received considerable attention since they combine the advantages of efficient mass transport from macropores and high surface area from mesopores [6, 7]. Various synthesis strategies have been developed to fabricate hierarchically macro-/mesoporous TiO2 [6]. The dual-templating synthesis approach employing a combination of both surfactant and colloidal crystal templating techniques offers a promising way for the fabrication of TiO2 with three-dimensionally (3D) ordered macropores and mesopores [8, 9]. An additional advantage of 3D ordered macro-/mesoporous (3DOM/m) TiO2 materials is that they exhibit enhanced light harvesting efficiency for photocatalytic and photovoltaic applications due to the multiple scattering and slow photon effects relating to their unique inverse opal photonic crystal structure [10, 11]. However, there have been few studies conducted on the production of 3DOM/m TiO2 mate
Data Loading...
