The synthesis and characterization of ytterbium-doped TiO₂ hollow spheres with enhanced visible-light photocatalytic activity

Abstract

SEM images of Melamine-formaldehyde polymer microspheres (MF) (a) and Yb-doped TiO2 hollow spheres (Yb-TiO2HS) (b).

Insights into the TiO2-Based Photocatalytic Systems and Their Mechanisms

“…The mechanism of cation doping is essentially to tune the Fermi level and electronic structure of d-electron configuration in TiO 2 , thereby to tune the energy levels to absorb the visible light energy and to enhance the overall photocatalytic efficiency of the system as shown in Figure 4a Consequently, there have been many cations doped in TiO2 towards enhancing its PC activities. In such cation doping, TiO2 has been doped with the (i) transition metals such as Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Cd, and W [73][74][75][76][77][78][79][80][81][82][83][84]; (ii) rare-earth metals such as Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb, and La [85][86][87][88][89]; and (iii) other metals such as Li, Mg, Ca, Se, Sr, Al, Sn, and Bi [90][91][92][93][94][95][96][97]. In the case of rare earth elements doping, the electronic configurations such as 4f, 5d, and 6s are found to be favorable to tune the band edge positions, density of states, and width of VB and CB via altering the crystal, electronic, and optical structures in TiO2 [98][99][100].…”

Zinc‐Doped Nickel Oxide Hollow Microspheres – Preparation Hydrothermal Synthesis and Electrochemical Properties

“…Template methods had superiority in the morphology control of hollow microspheres. Various hard templates such as polystyrene microspheres, polymethacrylate microspheres, carbon microspheres,, and silicon dioxide microspheres were used to prepare the metal oxide hollow microspheres. And various soft templates such as supramolecular micelle and polymer microcapsule were also used in the preparation.…”

“…Hollow microspheres structure would offer a buffer space for metal oxides to fit the change of the volume in the charge–discharge processes, which also could lead to the improvement of the electrical conductivity. The preparation methods of hollow microspheres have attracted much attention, including the template method (such as hard templates and soft templates) and template‐free method, (such as hydrothermal method and self‐assembly method). Among numerous preparation methods, hydrothermal method, has many advantages such as simplicity of operator, low cost, and high output.…”

One-pot synthesis of Cu2O/C@H-TiO2 nanocomposites with enhanced visible-light photocatalytic activity

“…In recent years, the excellent properties of TiO 2 hollow microspheres, with low density, high surface area, excellent surface permeability and high light-harvesting efficiency, are of interest to researchers. 6,[10][11][12][13][14][15] The large surface area provides more adsorption and reactive sites for photocatalytic reactions. The mesoporous hollow framework structure can not only promote the rapid transportation of the transmission medium, but also improve the multi-light scattering/reection to enhance the absorption rate of light and further enhance the photocatalysis.…”