Synthesis of Fibrous Sm3+-Doped Titanium Dioxide Using Collagen Fiber As a Template and Its Photocatalytic Properties

Abstract

Fibrous Sm3+-doped TiO2 (Sm/TiO2) was prepared using collagen fibers as a template. Samples were calcined at different temperatures to prepare TiO2 as well as Sm/TiO2, and effects of Sm-doping on crystallization, crystal transformation and grain size were investigated in detail. The morphology, crystalline structure, diffuse reflection spectrum and element chemical status of the products were characterized using scanning electron microscopy (SEM), X-ray diffractometer (XRD), ultraviolet visible spectrophotometry (UV–Vis DRS) and X-ray photoelectron spectroscopy (XPS), respectively. The photocatalytic performance was evaluated by the following degradation of methyl orange. The results show that the original fiber structure of collagen template is fully preserved when calcinations are carried out at 500–700°C. Sm-doping has an significant effect on crystallization and grain size of TiO2. After samarium doping, the band gap of sample decreased from 3.06 to 3.02 eV, the product has a significant red shift of optical absorption band edge, and the absorbance is also enhanced in visible region. The orbit component of O 1s for 4% Sm–TiO2 is shifted to a higher binding energy. The biggest enhancement in photocatalytic activity was obtained with a dopant amount of 4% samarium calcined at 600°C, and the degradation rate of methyl orange reaches 98.22% after 40 min using metal halide lamp (350 W) as illuminant, which is much higher than that of undoped one.