Preparation of Gd-Doped TiO2 Nanotube Arrays by Anodization Method and Its Photocatalytic Activity for Methyl Orange Degradation

Abstract

Gd-doped TiO2 nanotube arrays with 3D ordered and high specific surface (176 m2/g) area are successfully prepared on a Ti foil surface via an anodizing method. The characterizations of Gd-doped TiO2 nanotube arrays are carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectrometer (EDX), optical contact angle measurer, and ultraviolet (UV) fluorescence spectrophotometer, respectively. The results reveal that the Gd-doped TiO2 nanotube arrays form on the Ti foil surface with a length of about 50.5 μm and 100 nm in diameter, and the growth direction grown along the (101) direction of anatase crystal. Under the optimized reaction conditions (60 V, 10 h, 0.01mol/L Gd3+), the crystal phase of Gd-doped TiO2 show an excellent nanotube structure, possess a beneficial photocatalytic performance for methyl orange (MO) (Degradation rate was 95.8%) and an excellent hydrophilic property (The optical contact angle was 4.9°). After doping with Gd, the hydrophilic and photocatalytic properties of the TiO2 nanotubes are further improved.

Synthesis, characterization, mechanical and magnetic characteristics of Gd3+/PO43− substituted zircon for application in hard tissue replacements

“…The binding energy (BE) values (Table 2) corresponding to O 1 s (Figure 6A) confirm its 2 − state and meanwhile, the doublet and singlet that are respectively determined for Zr 3 d (Figure 6B) and Si 2 p (Figure 6C) confirms their 4 + state and further the reasonably high BE values noticed for these individual elements (Zr 4+ , Si 4+ and O 2− ) than the pristine oxides of ZrO 2 and SiO 2 establish the crystallization of ZrSiO 4 in the system 52,53 . The BE for Gd 4 d (Figure 6E) and P 2 p (Figure 6F) confirmed their oxidization states of 3 + and 5 + in both 10GPZS and 40GPZS systems 54–57 . The BE values of Ti 2 p 3/2 (Figure 6D) determined as 458.38 and 458.08 eV, respectively, for 10GPZS and 40GPZS are relatively reduced than the value reported for individual TiO 2.…”

“…52,53 The BE for Gd 4d (Figure 6E) and P 2p (Figure 6F) confirmed their oxidization states of 3 + and 5 + in both 10GPZS and 40GPZS systems. [54][55][56][57] The BE values of Ti 2p emerge from the excess Gd 3+ /P 5+ in the system leading to the crystallization of GdPO 4 as an individual component. 59 While, the extent of distribution density of Gd 3+ /PO 4 3À were found relatively minimum in 10GPZS against the high density noticed in 40GPZS.…”

Synthesis and Characterization of ZnO-TiO2/Carbon Fiber Composite with Enhanced Photocatalytic Properties

“…Due to their wide band gaps, they are active only in the UV-light region, which is less than 5% of the solar light spectrum. In addition, the high recombination of electron-hole pairs of ZnO and TiO 2 leads to a low photon-to-electron conversion efficiency [ 18 , 19 , 20 , 21 , 22 ]. Therefore, improving photocatalytic activities via modification has become an important task.…”

Fabrication and Photocatalytic Properties of Electrospun Fe-Doped TiO2 Nanofibers Using Polyvinyl Pyrrolidone Precursors

“…For this reason, in the case of anatase TiO 2 with a bandgap of 3.2 eV, only a short wavelength no longer than 387.5 nm can be used for the reaction, which means that 95% of the sunlight incident on the earth cannot be used. Because these factors directly reduce the efficiency of the photocatalyst, various methods have been proposed to solve these issues, including elemental doping [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ], dye sensitization [ 24 , 25 , 26 ], and microstructure control [ 27 , 28 , 29 ]. In the case of elemental doping, the dopant acts as a trap for excited electrons or holes, which delays the recombination of electron–hole pairs.…”