Authors: T-L Hsiung, H.P. Wang, Y-L Wei
Affilation: National Cheng Kung University, Taiwan
Pages: 440 - 443
Keywords: ionic liquid, photocatalysis, mesoporous TiO2, EXAFS
A nitrogen-doped mesoporous TiO2 (N-TiO2) was synthesized using a room-temperature ionic liquid (RTIL) (C4mimBF4) as the template. By 1H NMR (Figure 1), interactions between Ti and nitrogen of the RTIL are observed. The nanosize mesoporous N-TiO2 (10-50 nm) possesses the anatase phase with pore openings of 5-8 nm (the TEM images shown in Figure 2). The band gap of the mesoporous N-TiO2 is 2.47 eV (determined by DR-UV/VIS spectra). The mesoporous N-TiO2 has a higher photoreactivity in photocatalytic degradation of methylene blue than the conventional nanosize N-TiO2 (shown in Figure 3). The refined extend X-ray absorption fine structure (EXAFS) data (Table 1) show that the Ti-O and Ti-Ti bond distances for the mesoporous N-TiO2 are 1.96 and 3.02 Å, respectively, suggesting that the nitrogen may be inserted into the framework of the TiO2 matrix.