La掺杂TiO2介孔微球的超声水热合成和光催化性能

摘要

With tetrabutyl orthotitanate (TBOT) as Ti source, La(NO3)3 · 6H2O as La source and octadecylamine as a template, La-doped mesoporous TiO2 microspheres were prepared by ultrasonic-hydrothermal method. The obtained samples were characterized by XRD, XPS, TEM, BET, UV-Vis, IR and FL.The results revealed that the appropriate molar fraction of La dopant could decrease crystalline size, increase specific surface area and weaken fluorescence intensity of mesoporous TiO2. Compared with P25, the gap adsorption edge of mesoporous La3+/TiO2 exhibited a little red shift and slightly narrowed their band gaps. For mesoporous La3+/TiO2 (2.0 at%), the specific surface area and the average pore diameter were 132.7 m2/g and 8.67 nm, respectively. Furthermore, the degradation ratio of methylene blue to mesoporous La3+/TiO3 (2.0at%) was up to 98.5%, which exhibited the best photocatalytic activity with the initial concentration of 40 mg/L for 120 min.%以钛酸四丁酯为钛源、硝酸镧为镧源、十二胺为模板剂,采用超声-水热法合成了La3+掺杂介孔TiO2微球,并利用XRD、XPS、TEM、BET、UV-Vis、IR、FL等手段表征了材料的结构、形貌、比表面积、孔径分布及光学性能.研究结果表明,适量La3+离子掺杂不仅能使介孔TiO2晶粒细化,比表面积增大,荧光强度减弱.La3+/TiO2的光吸收边红移,并具有比商业P25更好的光催化活性,其中介孔La3+/Ti02(2.Oat%)的比表面积和平均孔径分别为132.7 m2/g和8.67 nn,光催化降解初始浓度为40 mg/L的亚甲基蓝溶液120 min时,其降解率达到98.5%,表现出最强的光降解能力.