Preparation and Characterization of Photocatalysts

Wu, Y., Zhang, J., Xiao, L., and Chen, F. (2009) Preparation and characterization of Ti02 photocatalysts by Fe3+ doping together with Au deposition for the degradation of organic pollutants. Applied Catalysis B Environmental, 88 (3—4), 525—532. 

Moon, J., Takagi, H., Eujishiro, Y, Awano, M. 2001. Preparation and characterization of the Sb doped TiOj photocatalysts. J Mater Sci 36 949-955. 

In Part I the fundamental aspects of photocatalysis are described. Photoelectrochemical processes at semiconductors are the most important basics for all photocatalytic reactions (Chapter 2). Design, preparation and characterization of active photocatalysts have been an important research subject,... 

Design, Preparation and Characterization of Highly Active Metal Oxide Photocatalysts... 

A. Fernandez, G. Lassaletta, V.M. Jimenez, A. Justo, A.R. Gonzalez-Elipe, J.M. Herrmann, H. Tahiri, Y. Ait-Ichou, Preparation and characterization of TiC>2 photocatalysts supported on various rigid supports (glass, quartz and stainless steel). Comparative studies of photocatalytic activity in water purification, Appl. Catal. B Environ. 7 (1995) 49. 

W. Jin, H. Sun, Y. Bai, Y. Cheng, N. Xu, Preparation and characterization of visible-Ught-driven carbon-sulfur-codoped Ti02 photocatalysts . Industrial Engineering Chemistry Research, 45(14), 4971 976, (2006). 

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. 

Toyoda, M., B. Tryba, F. Kojin, S. Mozia, T. Tsumura, E. Itoh, and M. Inagaki, Preparation and characterization of carbon-coated TiOj photocatalysts— Hybridization of photocatalytic activity and adsorptivity for purification of water (Review). TANSO 2005 [No. 220] (2005) 289 299. 

Preparation and characterization of perovskite-type Xitania-bearing blast furnace slag photocatalyst. Mater. Sci. Semicond, Process, 11, 117-121. 

Isago T., Morino A., Kawai S., Nagami N., Sato S., Ishitsu H. Preparation and characterization of a Sn02/Ti02 bilayer thin film photocatalyst. J. Ceram. Soc. Jpn. 2001 109 789-792 Ishibashi K, Nosaka Y., Hashimoto K., Fujishima A. Time-dependent behavior of active oxygen species formed on photoirradiated Ti02 films in air. J. Phys. Chem. B 1998 102 2117-2120... 

Zhang X, Liu Q. Preparation and characterization of titania photocatalyst co-doped with boron, nickel, and cerium. Mater Lett 2008 62 2589-2592. 

S. Yuenyaw, K. Saito, E. H. Sekiya, and P. Sujaridworakun, Preparation and Characterizations of Yb-doped Ti02 Photocatalyst Films Prepared by RF-Magnetron Sputtering Process, lOP Conference Series Mater. Sd. Eng., 18,1-4 (2011). 

G. Tian, H. Fu, L. ling, B. Xin, and K. Pan, Preparation and Characterization of Stable Biphase Ti02 Photocatalyst with High CiystaUinity, Large Surface Area, and Enhanced Photoactivity, J. 

Sinha S.P. In Complexes of the Rare Earths. Pergamon Press, London, 1966 Smirnova N., Eremenko A., Rusina O., Hopp W, Spanhel L. S)mthesis and characterization of photocatalytic porous Fe +/Ti02 layers on glass. J. Sol-Gel Sci. Technol. 2001 22 109-113 Sonawane R.S., Hegde S.G., Dongare M.K. Preparation of titanium(IV) oxide film photocatalyst by sol-gel dip coating. Mater. Chem. Phys. 2002 77 744-750... 

Anderson C., Bard A. J. Improved photocatalytic activity and characterization of mixed Ti02/Si02 and Ti02/Al203 materials. J. Phys. Chem. B 1997 101 2611-2616 Anderson C., Bard A.J. An-improved photocatalyst of Ti02/Si02 prepared by a sol-gel synthesis. J. Phys. Chem. 1995 99 9882-9885... 

Recently, it is reported that Xi02 particles with metal deposition on the surface is more active than pure Ti02 for photocatalytic reactions in aqueous solution because the deposited metal provides reduction sites which in turn increase the efficiency of the transport of photogenerated electrons (e ) in the conduction band to the external sjistem, and decrease the recombination with positive hole (h ) in the balance band of Xi02, i.e., less defects acting as the recombination center[l,2,3]. Xhe catalytic converter contains precious metals, mainly platinum less than 1 wt%, partially, Pd, Re, Rh, etc. on cordierite supporter. Xhus, in this study, solutions leached out from wasted catalytic converter of automobile were used for precious metallization source of the catalyst. Xhe XiOa were prepared with two different methods i.e., hydrothermal method and a sol-gel method. Xhe prepared titanium oxide and commercial P-25 catalyst (Deagussa) were metallized with leached solution from wasted catalytic converter or pure H2PtCl6 solution for modification of photocatalysts. Xhey were characterized by UV-DRS, BEX surface area analyzer, and XRD[4]. 

Anpo, M. (Ed.) Special issue "Preparation, Characterization, and Reactivities of Titanium Oxide-based Photocatalysts, Topics Catal. 35,1 (2005). 

In the present study, highly dispersed titanium oxides included within the zeolite cavities (Ti-oxide/Y-zeolite) and framework (Ti-MCM-41,-48) were prepared using an ion-exchange method and hydrothermal synthesis to be used as photocatalysts for the reduction of CO2 with H2O at 328 K. The characterization of these catalysts by means of in situ photoluminescence, diffuse reflectance absorption, XAFS (XANES and FT-EXAFS), and ESR measurements have been carried out and special attention has been focused on the relationship between the structure of the titanium oxide species and the reaction selectivity in the photocatalytic reduction of CO2 with H2O to form CH3OH. 

From the results presented in the previous paragraphs, it follows that catalytic activity and chemoselectivity of a semiconductor photocatalyst should depend on intimate details of preparation. In addition to careful description of the synthetic details, it is important to characterize the obtained powder by bulk and sur-... 

In order to prepare such well-defined photocatalytic systems, it is necessary to clarify at the molecular level the chemical features of the photo-formed charge carriers, the reaction intermediate species, as well as the reaction mechanisms using various spectroscopic techniques. These studies, in turn, will necessitate detailed and comprehensive investigations of the photogenerated active sites and the local structures of the photocatalysts (20-27). We have conducted detailed characterizations of potential photocatalysts using various molecular spectroscopies in order to realize two main objectives (1) A clarification of the dynamics and mechanisms of the photoactive... 

Despite the importance of solid-state nuclear magnetic resonance (NMR) spectroscopy for the characterization of solid catalysts, in situ studies related to photocatalysts are rare. Mills and O Rourke [59] monitored the selective photooxidation of toluene by in situ NMR using an NMR tube as the photoreactor. A Ti02 precursor paste was prepared by hydrolysis of titanium propoxide and following treatment at 228 °C. The obtained anatase-type titania was mixed with poly(vinyl alcohol). The obtained paste was coated on the walls of the NMR tube, rotated over night and calcined. In parallel, batch experiments were carried out. The reaction mixture containing the catalyst was directly placed into the tube, which was irradiated outside the spectrometer and then inserted into the NMR spectrometer. 

Numerous studies on Ti02 (titania) and Ti02-derived photocatalysts have been carried out not only regarding fundamental mechanisms and photoactivity characterization but also on the preparation processes of photocatalysts, the improvement in photocatalytic performance, and the development of procedures for practical applications. 

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