介孔TiO₂催化臭氧氧化去除废水中氯酚的研究

Study on Degradation of Trichlorophenol by Meso-Porous TiO₂ Catalyzed Ozonation

以市场P25为前驱体用水热法制备出TiO2介孔材料,催化剂的表征采用透射电子显微镜、比表面分析仪以及X射线衍射技术,通过表征结果发现介孔TiO2的形貌、晶相比例受反应水热温度及煅烧温度控制,且随着两者温度的升高,介孔TiO2的比表面积及孔径会逐渐减小,晶相由锐钛矿逐渐转向金红石相。用制备的介孔TiO2催化材料联合臭氧降解2,4,6-三氯酚水溶液来评价TiO2介孔纳米材料臭氧催化性能,研究结果表明:介孔TiO2协同臭氧降解的2,4,6-三氯酚的效率较单独臭氧及市场P25都有明显的改善,且TiO2纳米管协同臭氧降解氯酚效率最高,另外,TiO2催化剂中金红石相越多,其臭氧催化性能越好。

TiO2 Meso-porous material was prepared from Degussa P25 by using hydrothermal method after annealing in different temperature. Catalyst samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) analysis. Results indicate that various morphology (nanotube, nanorod, nanopolyhedron and nanoparticles) and crystallite phases (ratios of anatase and rutile) were synthesized by varying hydrothermal temperature and annealing temperature. SBET and Pore size decreases with increased hydrothermal temperature and sintering temperature. Calcination temperature plays an important role in crystal composition of the catalysts. The samples were used as catalysts for degradation of 2,4,6- trichlorophenol (2,4,6-TCP) by ozone. Removal efficiency of 2,4,6-TCP was significantly promoted in the presence of catalyst compared with that of ozone alone. The nanotube TiO2 showed the best activity, and the higher rutile phase ratios showed higher catalytic ozonation.