Ultrasonic-hydrothermal Synthesis and Photocatalytic Activities of La-doped Mesoporous TiO_2 Microspheres

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 ob-tained samples were characterized by XRD,XPS,TEM,BET,UV-Vis,IR and FL.The results revealed that the ap-propriate 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+/TiO2(2.0at%) was up to 98.5%,which exhibited the best photocatalytic activity with the initial concentration of 40 mg/L for 120 min.