涂覆型TiO_2光催化材料的制备及光催化性能研究

Preparation and photocatalytic properties of coated TiO_2 photocatalytic material

以溶液凝胶法制备TiO_2溶胶,用氧化铝球为载体,采用浸渍法制备涂覆型TiO_2光催化材料用XRD、SEM、UV-Vis等方式进行性能表征;将制备的涂覆型TiO_2光催化材料装入自制的管式光催化反应器中,以甲苯为目标污染物,研究了其光催化性能。结果表明,氧化铝球载体涂覆前后形貌发生改变,涂覆后氧化铝球载体表面包裹一层较为均匀光滑的锐钛矿相TiO_2,该晶相对紫外光源吸收率更高。并考察涂覆方式、光源、甲苯进气浓度、停留时间、相对湿度等因素对涂覆型TiO_2光催化性能的影响。试验发现,在相同条件下,涂覆型TiO_2比喷涂型TiO_2去除甲苯效率高20%左右。且在光源为254nm,甲苯进气浓度43mg/m^3,停留时间117s,相对湿度70%条件下,涂覆型TiO_2对甲苯去除率可高达80%左右。

The TiO 2 photocatalyst coated on spherical alumina supporter was prepared by using sol-gel method to produce colloidal TiO 2 and dip-coating press.The surface structure of the synthesized samples was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM)and ultraviolet-visible spectroscopy(UV-Vis).With toluene gas as the target pollutant,the prepared coated TiO 2 photocatalyst material was filled into a self-made tube type photo-catalytic reactor in order to study its photocatalytic degradation performance.The results show that the morphology of the coated TiO 2 photocatalyst material was obviously different from that of the original coat.It reveals that a smooth and uniform layer formed by anatase TiO 2 was deposited on the alumina supporter.The adsorption of anatase TiO 2 towards ultraviolet light source is higher than other crystal phase TiO 2.The influence of coating type,light source,toluene inlet concentration,residence time,relative humidity and other factors on the photocatalytic performance of coated TiO 2 photocatalyst material was investigated.It was found that under the same conditions,the coated type TiO 2 is 20%higher than the sprayed type TiO 2 about removing toluene gas.In addition,the removal rate of toluene by coated TiO 2 photocatalyst material can be up to 80%,when the wavelength of ultraviolet light is 254 nm,the inlet concentration of toluene is 43 mg/m 3,the residence time of toluene gas is 117 s,and the relative humidity of gas is 70%.