Preparation and photocatalytic activity of Gd 3+-doped trititanate nanotubes

Abstract

Trititanate nanotubes were prepared using hydrothermal method and then doped with Gd 3+ through ion-exchanging with H +. The doping level of Gd/Ti in nanotubes changed from 0.053 to 0.071 while the concentration of Gd 3+ varied from 0.1 to 0.2 mol L −1. The nanotubes were characterized by X-ray photoelectron spectra (XPS), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), UV–Vis diffusion reflection spectra (UV–Vis DRS) and photoluminescence (PL) spectra. The photocatalytic activities were investigated with Rhodamine B aqueous solution of 2.5 × 10 −5 mol L −1 as the model pollutant. A 300 W mercury lamp (dominant wavelength 365 nm) and a 350 W xenon lamp with 400-nm cutoff filter were used as light source, respectively. The results indicated that the photocatalytic efficiency was affected by many factors, such as crystal structure, particle size, surface area and doping amount, etc. Gd 3+ doping enhanced the photocatalytic efficiency of TiO 2 in both UV and visible light regions. In the visible region (>400 nm), the photocatalytic efficiency of TiO 2 was increased by 1.78 times.