Titania nanoparticles

Calza, P., Pelizzetti, E., Mogyorosi, K, Kun, R., and Dekany, I. (2007) Size dependent photocatalytic activity of hydrothermally crystallized titania nanoparticles on poorly adsorbing phenol in absence and presence of fluoride ion. Applied Catalysis B Environmental, 72 (3 1), 314-321. 

Lorret, O., Franco va, D., Waldner, G., and Stelzer, N. (2009) W-doped titania nanoparticles for UV and visible-light photocatalytic reactions. Applied Catalysis B Environmental, 91 (1-2), 39-46. 

Lam, S.W., Soetanto, A. and Amal, R. (2009) Self-cleaning performance of polycarbonate surfaces coated with titania nanoparticles. Journal of Nanoparticle Research, 11, 1971-1979. 

Chen, X.B. and Burda, C., Photoelectron spectroscopic investigation of nitrogen-doped titania nanoparticles, J. Phys. Chem., 108,15446, 2004. 

Takagi M, Maki T, Miyahara M, Mae K (2004) Production of titania nanoparticles by using a new microreactor assembled with same axle dual pipe. Chem Eng J 101 269... 

Sun, J., et al., Single-walled carbon nanotubes coated with titania nanoparticles. Carbon, 2004. 42(4) p. 895-899. 

Takenaka, S., et al., Coverage of carbon nanotubes with titania nanoparticles for the preparation of active titania-based photocatalysts. Applied Catalysis B Environmental, 2012. 125(0) p. 358-366. 

Iwabuchi A, Choo CK, Tanaka K Titania Nanoparticles Prepared with Pulsed Laser Ablation of Rutile Single Crystals in Water J Phys Chem B 108 10863-10871... 

The observed phase selectivity phenomenon vividly shows that the crystalline phase of titania nanoparticles has a major effect on their reactivity. A similar phenomenon had been recently described for dissolution of a similar Ti02 sample in HF.16 This reaction can be used for the preparation of a pure nanoscale rutile phase for use as a photocatalyst. 

FIGURE 10.1 (a) Effect of the number of particles counted on the average mean primary particle diameter, r/j (circles), and Sauter mean primary particle diameter, (squares), as well as the geometric standard deviation (that is, a measure of the width of the size distribution, triangles), (b) The corresponding primary particle size distribution and a TEM picture of the investigated titania nanoparticles collected with a thermophoretic sampler directly from a premixed TiOj flame at a height of 0.5 cm above the burner. (Courtesy of H.K. Kammler and S.E. Pratsinis.)... 

Tsantilis, S., Kammler, H.K., and Pratsinis, S.E., Population balance modeling of flame synthesis of titania nanoparticles, Chem. Eng. Set, 57, 2139, 2002. Madler, L., Stark, W.J., and Pratsinis, S.E., Simultaneous deposition of Au nanoparticles during flame synthesis of Ti02 and Si02, J. Mater. Res., 18, 115, 2003. Tani, T., Madler, L., and Pratsinis, S.E., Synthesis of zinc oxide/sihea composite nanoparticles by flame spray pyrolysis, J. Mater. Set, 37, 4627, 2002. 

Kammler, H.K., and Pratsinis, S.E., Carbon-coated titania nanoparticles continuous, one-step flame-synthesis, J. Mater. Res., 18, 2670, 2003. 

SANS is useful in examining pore structures in nanoporous materials, or water in fractal networks (Li et al. 1994). Examples of aggregation-state analyses include studies of silica and titania nanoparticles (Hyeon-Lee et al. 1998), catanionic surfactants (Brasher and Kaler 1996) and Ti02-Si02 and Zr02-Si02 sol-gel materials (Miranda Salvado et al. 1996). Particle size distributions obtained via SANS, SAXS and TEM on nanophase Ti02-V02 catalyst particles are compared by Albertini et al. (1993). 

This simple picfure can only be partly correct, as it has been shown that both unsupported ultrafine titania nanoparticles [10] and silica-supported monodis-persed subnanometric titania particles [11] are active catalysts for olefin epoxidation with hydroperoxides. In these small titania particles, the titanium atoms possess coordination states between four and six. Quanfum chemical calculations derived similar activation energies for oxygen transfer on mononuclear four- and five-coordinafed fifanium sifes [12,13]. 

Finnegan, M.P., Zhang, H., and Banfield, J.F., Phase stability and transformation in titania nanoparticles in aqueous solutions dominated by surface energy, J. Phys. Chem. C, 111, 1962, 2007. 

W.J. Stark, K. Wegner, S.E. Pratsinis, A. Baiker, Flame Aerosol Synthesis of Vanadia-Titania Nanoparticles Structural and Catalytic Properties in the Selective Catalytic Reduction of NO by NH3, J. Catal. 197 (2001) 182. 

Fig. 1. TEM image of an ultramicrotome of the titania network constructed using a polymer gel template, showing the individual titania nanoparticles of which the structure is composed. Reprinted with permission from [7]. Copyright 2001 American Chemical Society...

Table 1. Properties of the titania networks obtained by using polymer gel templates calculated porosity, surface area obtained from nitrogen adsorption, pore, and titania nanoparticle diameters. Adapted with permission from [8]. Copyright 2001 American Chemical Society ...

The cements containing active photocatalytic titania nanoparticles have widespread applications to create environmentally clean surfaces. These applications include self-cleaning surfaces, anti-soiling, depollution of VOCs and NOx contaminants and antifungal/microbial activities [521-528]. The relevant photocatalytic processes may occur both at the air-solid interface and at the liquid-solid interface. 

Figure 2 shows a band diagram of the dye-sensitized nanocrystalUne solar cell (DSC) and explains its operational principle. Sunlight is harvested by the sensitizer that is attached to the surface of a large band gap semiconductor, typically a film constituted by titania nanoparticles. Photo-excitation of the dye results in the... 

Fig. 13 Photo-induced processes occurring during photovoltaic energy conversion at the surface of the nanocrystalline titania films, 1 sensitizer (S) excitation by light, 2 radiative and nonradiative deactivation of the sensitizer, 3 electron injection in the conduction band followed by electron trapping and diffusion to the particle surface, 4 recapture of the conduction band electron by the oxidized sensitizer (S+), 5 recombination of the conduction band electrons with the oxidized form of the redox couple regenerating the sensitizer and transporting the positive charge to the counterelectrode. Grey spheres, titania nanoparticles, red dots, sensitizer, green and blue dots oxidized and reduced form of the redox couple. See Color Plates...

The paper is devoted to development of novel approach to dope coatings with active anticorrosion species with self-healing ability. They contain nanoreservoirs which can store active agents and provide controllable release of them. The titania nanoparticles doped with cerium ions and organic inhibitors were used as nanocontainers to dope the hybrid sol-gel matrix and to provide long-term corrosion protection. 

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