Preparation of Cost-Effective TiO2-Outerloaded Porous Lava Composites using Supercritical CO2 and Their Photocatalytic Activity for Methylene Blue Degradation

Cost-effective TiO2-outerloaded lava composites (TOLs) were prepared using supercritical CO2 and sealing lava as well as tetrabutyl titanate as a support and a precursor, respectively. The important factors affecting methylene blue (MB) oxidation efficiency were investigated including the initial concentration of MB, the pH, and catalyst concentration. The results show that TOLs have a higher degradation efficiency than pure TiO2 and TiO2-loaded lava composites (TLLs) because of the high adsorption capacity of MB and the small crystalline size of the TiO2 particles in addition to a synergetic effect for adsorption and photocatalytic degradation. The optimum conditions were a MB concentration of 1.5 mg/L at pH 8 with a TOLs concentration of 6.8 mg/L for the fastest MB degradation. Additionally, the used TOLs retained high activity for MB photocatalytic degradation.

摘 要： 以钛酸丁酯为前驱体, 封堵的火山岩为载体, 通过超临界 CO2 辅助制备了 TiO2 外负载火山岩复合体, 并将其用于光催化降解亚甲基蓝反应, 考察了溶液 pH 值及催化剂浓度对反应性能的影响. 结果表明, TiO2 外负载火山岩复合体的光催化性能优于纯 TiO2 和 TiO2 体负载火山岩复合体. 这是由于外负载复合体对亚甲基蓝的高吸附性、小晶粒尺寸的 TiO2 颗粒以及吸附和光催化降解间的协同效应. 亚甲基蓝浓度为 1.5 mg/L, 溶液 pH 为 8, 催化剂浓度为 6.8 mg/L 时, 外负载 TiO2 火山岩复合体上亚甲基蓝降解速率最高, 且使用后的催化剂仍具有高的光催化活性.

This article reports on a novel supercritical CO2-assisted procedure for the synthesis of cost effective TiO2-outerloaded lava composites, which are photocatalytically active during methylene blue degradation.Figure optionsDownload as PowerPoint slide