Experimental study on photocatalytic degradation efficiency of mixed crystal nano-TiO₂ concrete

Abstract

<jats:title>Abstract</jats:title><jats:p>The photocatalytic mixed crystal nano-TiO<jats:sub>2</jats:sub> particles were incorporated with concrete by means of the internal doping method (IDM) and spraying method (SPM) in this paper. To evaluate the photocatalytic degradation efficiency of mixed crystal nano-TiO<jats:sub>2</jats:sub> concrete, the methyl orange (MO) was chosen to simulate pollutants. The physicochemical characteristics and photocatalytic performance of mixed crystal nano-TiO<jats:sub>2</jats:sub> concrete prepared by above two different methods were experimentally investigated under UV irradiation and solar irradiation. Furthermore, the effects of two key influential factors including pollutant concentration and irradiation condition were also analyzed and discussed. Experimental results indicate that the nano-TiO<jats:sub>2</jats:sub> concrete prepared by the spraying method (SPM) exhibits maximum photocatalytic degradation efficiency of 73.82% when the sprayed nano-TiO<jats:sub>2</jats:sub> slurry concentration is 10mg/L. The photocatalytic degradation efficiency of unpolished nano-TiO<jats:sub>2</jats:sub> concrete is much higher than that of polished nano-TiO<jats:sub>2</jats:sub> concrete under the same exposure time of UV irradiation. Moreover, the photocatalytic degradation efficiency of nano-TiO<jats:sub>2</jats:sub> concrete decreases with the increase of pollutant concentration. The irradiation condition has an obvious influence on the photocatalytic degradation efficiency of nano-TiO<jats:sub>2</jats:sub> concrete. In the aspect of applications, the practical recommendations for the nano-TiO<jats:sub>2</jats:sub> concrete with self-cleaning capacity were presented according to the experimental results.</jats:p>

A review of the effect and optimization of use of nano-TiO2 in cementitious composites

“…In addition, application of nano-TiO2 photocatalysis on cement-based materials in urbanized areas can lead to air pollution reduction and air quality improvement in these areas [39,[45][46][47]. It has been found that concentration of organic, such as volatile organic compounds, and inorganic pollutants, such as NOx and SO2, can be reduced with the use of nano-TiO2 [19,29,36,[38][39][40]44,45,[47][48][49][50]. Such functionalities have the potential to improve the sustainability of construction materials [45].…”

Effect of Free Formaldehyde on Chemical Structure and Thermal Properties of Nano-Titanium Dioxide Resin

“…The study of Zaer-Miri and S. showed that the photocatalytic degradation of formaldehyde gas by the photocatalytic coating containing modified nano-titanium dioxide could reach 70% [ 5 ]. Guo's study proved that under the lighting condition of 12 36 W fluorescent lamps, the removal rate of formaldehyde by photocatalytic coatings containing TiO 2 increased significantly [ 6 ]. Bai's study showed that in the visible light region, the degradation performance of organic pollutants by TiO 2 photocatalytic coatings mixed with Ag was significantly improved, and the removal rates of benzene and formaldehyde reached 69.1% and 71.1% within 24 h, respectively [ 7 ].…”

Ozone Formation during Photocatalytic Oxidation of Nitric Oxides under UV Irradiation with the Use of Commercial TiO2 Photocatalytic Powders

“…Three commercial well-known photocatalytic powders (anatase-TiO 2 ) [ 37 , 38 , 39 ] were tested: AEROXIDE ® TiO 2 P25 by Evonik (referred to as P25), KRONOClean ® 7050 by KRONOS ® (referred to as K7050), and KRONOClean ® 7000 by KRONOS ® (referred to as K7000). Pure silica powder was used as a reference.…”