Authors: FilofteiaLaura Toma LutzMichael Berger Irina Shakhverdova Beate Leupolt Annegret Potthoff Kathrin Oelschlägel Tobias Meissner José Antonio Ibáñez Gomez Yolanda de Miguel
Publish Date: 2014/03/14
Volume: 23, Issue: 7, Pages: 1037-1053
Abstract
Photocatalytic properties of titania have been studied very intensively for a variety of applications including air and water purification In order to clarify the influence of the phase composition and other parameters thermal spraying with suspensions was applied to produce photocatalytically active titania coatings starting from two commercially available anatase and rutile submicron powders Aqueous suspensions containing 40 solids by weight were sprayed with an HVOF process using ethylene as the fuel gas The spray parameters were chosen in order to produce mechanically stable coatings and to preserve a high content of the initial crystalline phases of the powders The coating microstructures phase compositions and surface properties were characterized The photocatalytic performance was evaluated by degradation of the pink dye Rhodamine B RB using two techniques degradation of an aqueous solution of RB and discoloration of impregnated RB All the coatings exhibited photocatalytic activity to varying degrees depending on the phase composition as well as other factors namely the coating microstructure surface morphology surface hydroxylation light absorption and interaction with the pollutantThe authors would like to thank B Wolf and S Schultz Fraunhofer IWS for help with the metallographic preparation and the spectroscopy measurements and Dr M Yamada Toyahashi University of Technology Toyahashi Japan for kind delivery of the ceramic substrates Part of this work was performed under DVS research project 02064 “Funktionalisierung von Keramikoberflächen durch thermisch gespritzte Schichten” “Functionalization of ceramic surfaces by thermal spraying” AiF No 17371 BR funded via AiF by the Federal Ministry of Economics and Technology within the framework of the program for promotion of “Industrial Joint Research IGF” The authors gratefully acknowledge this financial support
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