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Mesoporous titania materials

Bare CuOx-supported nanostructures showed some activity in H 2 production from methanol-water mixture under UV-visible irradiation [180]. Ni is also used as a dopant, and small amounts (1 wt.%) of this element in mesoporous titania guarantee good activity in water-methanol mixtures under UV-visible light [181]. Indium-tantalum oxide Ni-doped materials also provided photocatalysts with promising efficiencies for direct water splitting [182]. TiOz nanotubes doped with Ir and Co nanopartides were effective for visible light water splitting even in the absence of... [Pg.112]

Ao, Y., Xu, J., Fu, D., and Yuan, C. (2009) Synthesis of C,N, S-tridoped mesoporous titania with enhanced visible light-induced photocatalytic activity. Microporous and Mesoporous Materials, 122 (1—3), 1-6. [Pg.125]

Ordered mesoporous materials of compositions other than silica or silica-alumina are also accessible. Employing the micelle templating route, several oxidic mesostructures have been made. Unfortunately, the pores of many such materials collapse upon template removal by calcination. The oxides in the pore walls are often not very well condensed or suffer from reciystallization of the oxides. In some cases, even changes of the oxidation state of the metals may play a role. Stabilization of the pore walls in post-synthesis results in a material that is rather stable toward calcination. By post-synthetic treatment with phosphoric acid, stable alumina, titania, and zirconia mesophases were obtained (see [27] and references therein). The phosphoric acid results in further condensation of the pore walls and the materials can be calcined with preservation of the pore system. Not only mesoporous oxidic materials but also phosphates, sulfides, and selenides can be obtained by surfactant templating. These materials have pore systems similar to OMS materials. [Pg.125]

Ceria was loaded on mesoporous titania by deposition precipitation (DP) method. Before deposition, the mesoporous material was suspended in water by ultrasound technique. Ceria was deposited by precipitation of Ce(N03)3 6H2O with Na2C03 at 60 °C and pH 9.0. Analytical grade chemicals were used in the support preparation. The precipitate was aged in a course of 1 h at the same temperature, filtered and washed carefully until absence of N03 ions. The sample was dried under vacuum at 80 °C and calcined in air at 400 °C for 2 h. Ceria modifying additive is 20 wt.%. The sample was labeled as CeMTi. [Pg.1019]

S. Pavasupree, S. Ngamsinlapasathian, Y. Suzuki, S. Yoshikawa, Preparation and characterization of high surface area nanosheet titania with mesoporous structure Materials Letters, 61, 2973-2977, (2007). [Pg.141]

Improvement in the photocatalytic activity of these materials has been achieved in recent years by different methods including sensitization of the catalyst using dye molecules and doping the catalyst with norrmetals such as nitrogen, carbon, fluoride and iodide, and transition metals (Au, Pt, Ag, and Pd). Hahnemann and Ismail [110] have recently reviewed the recent developments in the syntheses of mesoporous TiOj as active photocatalysts by the surfactant assembly as well as the preparation and characterization of doped mesoporous Ti02 networks with transition metals ions, noble metals, and nonmetal species. Mesoporous titania nanoparticles will play an important role in the environmental protection and the search for renewable and clean technologies. [Pg.215]

Cell assemblies. As macroporous templates, these provide a facile bioinspired method for the synthesis of hierarchical macro-mesoporous titania with tunable macroporous morphology and enhanced photocatalytic activity [134]. This is also a simple and facile technique that can be used to prepare many types of metal oxide porous materials with good control over the pore size and morphology. [Pg.219]

Very recently, Kluson et al. [268] prepared mesoporous titania by using a Triton X-lOO/cyclohexane/aqueous phase system with w = 1. The rationale behind the selection of such a low w value was that this amount of water should be mainly associated with the hydroxyl group of the surfactant and not compete with the oil phase for solvating the chain oxyethylene groups. Titanium isopropoxide was the source material for Ti. The titania crystallite size varied from 4.1 to 11.3 nm depending on the particle processing temperature. At 200 C, the product was amorphous to pseudoamorphous at 550"C, anatase started appearing, and rutile was found to appear in addition at 650"C. At 850°C, both anatase and rutile were obtained. [Pg.110]


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