Preparation, Characterization and Photocatalytic Activity of Lanthanum Doped Mesoporous Titanium Dioxide

Lanthanum doped mesoporous titanium dioxide photocatalysts with different La content were synthesized by template method using tetrabutyltitanate （Ti（OC4H9）4） as precursor and Pluronic P123 as template. The catalysts were characterized by thermogravimetric dif ferential thermal analysis, N2 adsorption-desorption measurements, X-ray diffraction, and UV-Vis adsorption spectroscopy. The effect of La3＋ doping concentration from 0.1% to 1% on the photocatalytic activity of mesoporous TiO2 was investigated. The characterizations indicated that the photocatalysts possessed a homogeneous pore diameter of about 10 nm with high surface area of 165 m2/g. X-ray photoelectron spectroscopy measurements in- dicated the presence of C in the doped samples in addition to La. Compared with pure mesoporous TiO2, the La-doped samples extended the photoabsorption edge into the visible light region. The results of phenol photodecomposition showed that La-doped mesoporous TiO2 exhibited higher photocatalytic activities than pure mesoporous TiO2 under UV and visible light irradiation.

In situ synthesis of Ti^(3+) self-doped mesoporous TiO_2 as a durable photocatalyst for environmental remediation

This study developed a facile approach for in situ synthesis of a Ti3＋ self-doped mesoporous TiO 2photocatalyst by an evaporation-induced self-assembly method using TiC l3,water,and F127 as the titanium precursor,solvent,and soft template agent,respectively. The as-prepared samples were investigated by X-ray diffraction,N2 adsorption-desorption measurements,ultraviolet-visible diffuse reflectance spectroscopy,electron paramagnetic resonance,and transmission electron microscopy. The influence of different reaction parameters such as the dosage of F127 and calcination temperature on the photocatalytic performance of the resulting products was evaluated. The optimized product exhibited high photocatalytic activity and stability in the oxidation of nitric oxide in air and photocatalytic degradation of methylene blue. The excellent photocatalytic performance of the Ti3＋ self-doped mesoporous TiO 2 photocatalyst is attributed to the cooperation between the mesoporous structure and self-doped Ti3＋ enhancing light absorption and effectively suppressing the recombination of photogenerated electrons and holes.

Photocatalytic activity of cerium-doped mesoporous TiO_2 coated Fe_3O_4 magnetic composite under UV and visible light

A novel kind of magnetically separable photocatalyst of cerrium-doped mesoporous titanium dioxide coated magnetite （Ce/MTiO2/ Fe3O4） was prepared and its activities under UV and visible light were reported. The catalysts with Ce/MTiO2 shell and Fe3O4 core were prepared by coating photoactive Ce/MTiO2 onto a magnetic Fe3O4 core through the hydrolysis of tetrabutyltitanate （Ti（OBu）4, TBT） with precursors of ammonium ceric nitrate and TBT in the presence of Fe3O4 particles. The MTiO2 shell was for photocatalysis, the Fe3O4 core was for separation by the magnetic field and the doped Ce was used to enhance the photocatalytic activity of MTiO2. The morphological, structural and optical properties of the prepared samples were characterized by Bnmauer-Emmett-Teller （BET） surface area, transmission electron microscopy （TEM）, X-ray diffraction （XRD） and UV-vis absorption spectroscopy. The effect of cerrium-doped content on the photocatalytic activity was studied and the result revealed that 0.5 mol.% Ce/MTiO2/Fe3O4 exhibited highest photoactivity. The photocatalytic activities of obtained photocatalysts under UV and visible light were estimated by measuring the degradation rate of methylene blue （MB, 50 mg/L） in an aqueous solution. The results showed that the prepared photocatalyst was activated by visible light and used as effective catalyst in photooxi- dation reactions. In addition, the possibility of cyclic usage of the prepared photocatalyst was also confirmed. Moreover, Ce/MTiO2 was tightly bound to Fe3O4 and could be easily recovered from the medium by an external magnetic filed. So, the photocatalyst can be reused without any mass loss. It can therefore be potentially applied for the treatment of water contaminated by organic pollutants.

Mesoporous organic solar cells

The device configuration with mesoporous titanium dioxide(m-TiO2)has garnered considerable attention as a promising solution for high-stable perovskite and dye-sensitized solar cells,although its application in organic solar cells remains unexplored.In this communication,we have incorporated this structure into both bulk-heterojunction(BHJ)and single-component organic solar cells(SCOSCs).Surprisingly,mesoporous OSCs(M-OSCs)demonstrate a deteriorative efficiency in BHJ-type cells,whereas this configuration succeeds in SCOSCs,exhibiting competitive performance with planar OSCs(P-OSCs).This pioneering study has resulted in a competitive power conversion efficiency of 9.67%for m-TiO_(2)-based cells,marking a significant milestone in the advancement of OSCs.Importantly,profiting from the better ultraviolet resistance of m-TiO_(2)than zinc oxide,this M-OSC exhibits superior photostability than that of P-OSCs when subjected to continuous one-sun(AM1.5G)illumination.In its entirety,this research not only introduces the concept of M-OSCs for the first time but also unveils a novel device architecture poised to address the long-term stability concerns within the realm of OSCs.