Preparation and characterization of V-Loaded titania nanotubes for adsorption/photocatalysis of basic dye and environmental hormone contaminated wastewaters

摘要

Titania nanotubes (TNs) with high specific surface area have been widely studied due to its excellent catalytic activities, long-term stability, nontoxicity, and low cost. Basic violet 3 (BV3) dye and perchloroethylene (PCE) environmental hormone are recognized as difficult-to-treat pollutants and are discharged by a wide variety of sources. Therefore, the main objectives of the present work were to prepare V-loaded TN photocatalysts by an impregnation method and to characterize the adsorptive/photocatalytic properties, fine structures, adsorption/photodegradation mechanisms or removal efficiencies of dye and environmental hormone pollutants in waste-waters using V-TNs. Experimentally, FE-SEM and HR-TEM microphotos showed that the length and diameter of TNs were 100-150 and 10-30 nm, respectively. XRD weak vanadia patterns observed in V-TNs indicating the V2O5 nanoparticles are possibly well dispersed on the surface of TNs. The BET surface area and pore volume of TNs (V-TNs) are 312 (291) m(2)g(-1) and 1.054 (0.879) cm(3)g(-1) with N-2 type IV hysteresis isotherms, respectively. The EXAFS data showed that the 5% V-TNs had Ti (V) atoms coordinated by primarily TieO (VeO) with bond distances of 1.95 angstrom (1.71 angstrom) and coordination numbers of 2.29 (5.35). The removal efficiencies of BV3/PCE onto 5% V-TNs were 100 and 96%, respectively and loaded V2O5 is the main specimen that can promote the photocatalytic efficiencies significantly under visible light irradiation. Finally, adsorption and photocatalytic mechanisms of BV3/PCE onto V-TNs were examined using DKR/pseudo-second-order equations and Langmuir-Hinshelwood model.