水解方法对坡缕石负载TiO_2光催化性能的影响

The effects of different hydrolysable methods on the photocatalytic activity of TiO_2-coated palygorskite powder

采用水蒸气水解和直接加水水解方法制备了负载型坡缕石/TiO2,并以300W高压汞灯为光源,活性金黄BES的降解活性为实验对象,研究了催化剂的投加量、催化剂煅烧温度以及实验重复次数对活性金黄染料溶液光降解作用的影响,对制备的催化剂进行了光催化氧化对比实验。结果表明:催化剂的最佳煅烧温度是300℃,最佳投加量为1g/L,并且直接加水水解方法优于蒸气水解法,直接加水水解方法能得到锐钛矿型TiO2,而蒸气水解方法只能得到无定形态TiO2。2h后,直接加酸水解制备的催化剂对活性金黄BES的去除率可达93%。

TiOa-coated palygorskite powder was prepared by different hydrolysable methods. Photocatalytic activity of TiC）a-coated palygorskite powder was studied through photo-degrading the golden yellow BES dyestuff solution under a 300 W high-pressure mercury lamp. The amount of catalyst, the calcined temperature of catalyst and times of the repeated experiments on photo-degradation were studied. The experimental results show that 300 ℃ seems to be the most proper calcined temperature for the catalyst. This kind of catalyst prepared by hydrolysable method watered directly contains anatase TiO2. Nevertheless, it can only obtain amorphous TiO2 after the synthesis of catalyst hydrolyzed with steam. The experimental results show that, when the dosage is 1 g/L, hydrolysable method watered directly has more efficient catalytic activity compared with hydrolyzing with steam through contrast experiments of adsorption, photo-catalysis and repeated experiments. When the TiO2-coated palygorskite powder prepared by the hydrolysable method is watered directly, the decoloring rate can reach 93 % after 2 h of reaction.