H_2O_2增效TiO_2/凹凸棒石光催化体系降解亚甲基蓝

以钛酸四丁酯为前驱体,天然凹凸棒石为载体,采用溶胶凝胶法制备了TiO_2/凹凸棒石复合光催化剂,并用XRD、TEM对其进行表征.以亚甲基蓝染料为模拟污染物,采用300 W汞灯为紫外光源,以光催化实验来评价该催化剂的活性,并研究了H_2O_2的引入对光催化活性的影响.实验结果表明,H_2O_2能显著提高染料的脱色效率:亚甲基蓝的初始浓度为50 mg/L,催化体系为2 mmol/L H_2O_2+0.5 g/L TiO_2/凹凸棒石+UV(紫外线),光催化10 min后其脱色率为95%,相对于单独的0.5 g/L TiO_2/凹凸棒石+UV催化体系,其脱色率提高了约50%.全波段扫描显示,加入H_2O_2后,亚甲基蓝在290 nm对应的苯环吸收蜂急剧下降,665 nm对应的最大吸收峰则近乎消失,且没有新的吸收峰产生.

Degradation of Methylene Blue by Photoelectron Catalytic Oxidation System of H_2O_2-Assisted TiO_2/Palygorskite

In this study, tetrabutyl titanate was selected as precursor, and palygorskite was selected as carrier. TiO_2/ palygorskite composites were prepared by sol-gel method, and samples were characterized by XRD and TEM. The ap-plicability of H_2O_2 to increase the efficiency of TiO_2/palygorskite photocatalytic degradations was investigated, and Methylene Blue in aqueous solution was used as a model for this purpose. It was proved that H_2O_2 can rapidly in-crease the efficiency of degradation. When the initial Methylene Blue' s concentration was 50 mg/L, the degradation rate of 2 mmol/L H_2O_2 +0.5 g/L TiO_2/palygorskite + UV photocatalysis system reached 95% , which enhanced a-bout 50% compared to 0. 5 g/L TiO_2/palygorskite + UV photocatalysis system in 10min. The UV-VIS scanning showed that the absorption peak of benzene ring decreased sharply, and the peak at 665 nm almost disappeared at the present of H_2O_2, then no new absorption peaks could be detected.