Photocatalyst coatings

Miller LW, Tejedor-Tejedor MI, Perez Moya M, Johnson R, Anderson MA. Photocatalyst-coated acrylic waveguides for oxidation of organic compounds. Stud Surf Sci Catal 2000 130 1925-1930. 

Chapter 7 reports a scaling-up procedure for photocatalytic reactors. The described methodology uses a model which involves absorption of radiation and photocatalyst reflection coefficients. The needed kinetics is obtained in a small flat plate unit and extrapolated to a larger reactor made of three concentric photocatalyst-coated cylindrical tubes. This procedure is applied to the photocatalytic conversion of perchloroethylene in air and to the degradation of formic acid and 4-chlorophenol in water. 

A. Toyoda, L. Zhang, T. Kanki, N. Sano, Degradation of phenol in aqueous solution by Ti02 photocatalyst coated rotating-drum reactor (SC) , Journal of Chemical Engineering of Japan, 33, 188-191, (2000). 

Air pollution, especially nitrogen oxides (NOx) contamination from the combustion of hydrocarbons, is a particularly serious problem in urban areas. Despite serious efforts toward emission control, the concentrations of NO often exceed the air-quality standard, especially in large cities. Ti02 photocatalysis appears to be a promising technology for the removal of low concentrations of NO from ambient air [79]. Daikin Industries has demonstrated the efficient removal of NOx from indoor air using a photocatalyst coated on activated carbon [25]. According to their results, the indoor NOx concentration decreases from 0.1 ppm to 0.06 ppm (the air-pollution standard) in 25 minutes. 

Nimittrakoolchai O-U, Supothina S. Bactericidal activity and UV-filtering property of Ti02-based photocatalysts coated on curtain fabrics. Res Chem Intermed 2009 35(3) ... 

APPLICATION OF PHOTOCATALYST COATING TO WINDOWPANES The Contaminants on Glass and Photocatalyst... 

At present, this method is widely used for preparing photocatalyst coating films (Nishikawa, 2003). We also adopted this method. 

Takahama K. Photocatalyst coating materials. In All about Photocatalyst. Kogyou-Chousa-Kai, 2003, pp. 188-190... 

Recently, photocatalyst coating technology enabled to produce construction materials having advanced functions such as sterilizing, deodorizing and self-cleaning properties. 

Among various application fields of TiO photocatalysis in construction, building finishing materials with self-cleaning ability are most popular. Some prefabricated house manufacturers supplied new type of houses with photocatalyst-coated tile finishing or external finishing boards on the market a few years ago. 

In 0.1 wt% slurries, the average interparticle distance is so small that the measured rate of TCE conversion is much less than the potential mass transfer limit [117]. In contrast, with the catalyst immobilized on walls of tubes of several mm diameter, mass transfer influence may exist, and has been demonstrated with data for salicylic acid conversion in a coiled tube [68,116]. A clear variation of reaction rate with flow rate exists, and an analysis [117] suggested that the data are very strongly mass transfer influenced. A similar influence of fluid flow rate on the first order rate constant has been noted in chlorophenol degradation on photocatalyst-coated glass beads [36]. 

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