Fabrication of TiO2 Binary Inverse Opals without Overlayers via the Sandwich-Vacuum Infiltration of Precursor

• Published in: Langmuir 2011-04, Vol.27 (8), p.5157-5164
• Main Authors: Cai, Zhongyu, Teng, Jinghua, Xiong, Zhigang, Li, Yanqiang, Li, Qin, Lu, Xianmao, Zhao, X. S
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Devices and Applications: Sensors, Fluidics, Patterning, Catalysis, Photonic Crystals; Exact sciences and technology; General and physical chemistry; Photochemistry; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Porous materials
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la200111j

A sandwich-vacuum method was demonstrated for the fabrication of titania (TiO2) binary inverse opals with an open surface. In this method, a moisture-stable TiO2 precursor was backfilled into the interstitial spaces of polystyrene binary colloidal crystals (PS bCCs), which served as a template. Removal of the template by calcination yielded TiO2 binary inverse opals with a 3D-ordered macroporous (3DOM) structure. Optical reflectance spectra revealed the existence of a pseudostop band gap in the 3DOM TiO2 samples. The position of the pseudostop band gap shifted to the low-wavelength region as the number ratio of small over large PS spheres was increased in the template. The sandwich-vacuum method proved to be simple and rapid for the fabrication of TiO2 binary inverse opals without overlayers in large domains. The 3DOM TiO2 materials were used as a photocatalyst for the degradation of benzoic acid. Results showed that in comparison to TiO2 nanoparticles prepared under the same sintering conditions, the 3DOM TiO2 materials displayed enhanced photocatalytic activity.