Assessing optimal photoactivity on titania nanotubes using different annealing temperatures

Influence of Na content on behavior of NiMo catalysts supported on titania nanotubes in hydrodesulfurization

“…21-1272) [30]. This result is in line with previous reports [43,44], where the partial transformation of the layered nanotube structure into anatase domains, without changing the overall nanotubular structure, was detected by XRD and Raman spectroscopy after calcination of titania nanotubes at 400°C. In the case of our NiMo/TNT(0.1) catalyst, the formation of anatase domains was detected after the sulfidation treatment performed at 400°C for 4 h. Anatase phase formation was not observed in this catalyst prior to the sulfidation step (XRD results, Fig.…”

One-dimensional titania nanotubes annealed at various temperatures for the photocatalytic degradation of low concentration gaseous pollutants

“…The inner diameters of the TNTs lay in the range 4-8 nm, while the outer diameters ranged from 8 to 12 nm. These findings are similar to those of previous studies (Toledo-Antonio et al, 2010;Xue et al, 2011) in which TNTs prepared via a hydrothermal treatment of anatase or rutile TiO 2 powder maintained nanotubular features after heating to 400 • C, even though the thermal stability of TNTs is lower than that of a typical TiO 2 powder (Asapu et al, 2011;Nishijima, Fujisawa, Murakami, Tsubota, & Ohno, 2008). However, Asapu et al (2011) reported that the tube structure of the TNTs collapsed at 500 • C. 2 shows XRD images of the TNTs treated at various annealing temperatures and the unannealed TNTs.…”

“…silver, nitrogen, and phosphorus) as antibacterial agents. Applications have also been reported for chemical sensors, solar cells, and environmental treatment agents (Asapu et al, 2011;Lin, Rong, Ji, Fu, & Yuan, 2011;Toledo-Antonio et al, 2010;Ushiroda, Ruzycki, Lu, Spitler, & Parkinson, 2005). Furthermore, several research groups (Górska et al, 2008;Tachikawa, Tojo, Fujitsuka, Sekino, & Majima, 2006;Toledo-Antonio et al, 2010;Yu, Yu, & Cheng, 2007) have found that TNTs possess superior photocatalytic action to that of anatase TiO 2 nanoparticles for the photocatalytic oxidation of a variety of environmental pollutants, including aqueous phenol compounds, methyl orange, and reactive blue 69 dye.…”

HDS performance of NiMo catalysts supported on nanostructured materials containing titania

“…Thus, the absorption band maximum was observed at about 300 nm for both nanotubular materials, whereas the absorption edge was located at 365 and 360 nm for NT(3) and NT(5), respectively, indicating an increase in the band-gap energy (E g ) of these materials to 3.4-3.5 eV. These differences in the electronic properties of the TiO 2 precursor and nanotubular titania samples can be attributed to a transformation of the bulk TiO 2 anatase into nano-sized titania structures (titania nanotubes) [31,32]. In the DRS spectra of Ti-SBA-15 and Ti-SBA-16 further blue shift can be observed; the absorption band maxima are located at about 230 nm and the absorption edge at 320 and 300 nm, respectively.…”