Preparation And Properties Of Titanium Dioxide Photocatalytic Concrete

The increasingly serious environmental pollution becomes larger scope,more difficult to against and more severe harm with the development of the society.The past research mainly concentrated in the wastewater treatment to solve these environmental problems.For now,road traffic and air pollution caused by industrial production has become one of the major problems in a big city or urban areas.Despite increased emissions control requirements and increase the system installation,air pollution,especially from the diesel engine pollutants（NO）will continue to be a serious problem in the future.Heterogeneous photocatalysis is a very effective method to realize the reduction of NOx emission.And titanium dioxide（TiO₂）has moderate performance,high catalytic efficiency and relatively cheap cost,those make its technology has been widely used in concrete research.This article focuses on the preparation of TiO₂ photocatalytic concrete and the property of the wear resistance.According to the reported from the literature and books,firstly,the gas phase photocatalytic reaction on-line testing device was setted up.And then,the evaluation system of the gas phase photocatalytic wsa determined.Through online test,the NO concentration of photocatalytic removal rate can be determined,and then the photocatalytic performance of the concrete was determined.In order to avoid agglomeration of nano photocatalyst,the dispersion experiments of photocatalyst were carried out during preparation of photocatalytic slurry.Through metallographic microscope,the analysis of different experimental conditions on the properties of photocatalyst dispersion was studied.The dispersion effect of TiO₂ slurry with sodium dodecyl sulfate（SDS）and dodecyl trimethyl ammonium bromide（CTAB）is the best.For the poorer wear-resisting performance,the photocatalytic concrete was prepared by sparying slurry obtained by adding binder paste silane coupling agent and sodium silicate.The photocatalytic concrete with high photocatalytic performance and better wear resistance was achieved.Apart from external factors,this article also changed photocatalytic concrete from the catalyst itself for further research.The Ag-TiO₂ and black C-TiO₂ photocatalytic concrete were prepared and both have good photocatalytic performance.Compared with zero dimensional nanometer materials,the nanowires array structure has a larger surface or volume.Especially,it is conducive to the absorption of light energy and light carrier move quickly when they have linear electronic transmission characteristics.And the mechanics properties of the nanofibers also can strengthen the surface strength of concrete while maintaining the good photocatalytic performance.So the TiO₂ nanowires photocatalytic concrete was prepared successfully.The performance characterization of prepared photocatalytic concrete was achieved by the scanning electron microscope,wear-resisting performance test and photocatalytic test.The results showed that the photocatalytic performance（NO gas removal rate）of TiO₂ nanowires photocatalytic concrete wear reached 62%,and it can keep this rate more than 55%after polishing.