A facile one-pot synthesis of N-La codoped TiO 2 porous materials with bio-hierarchical architectures and enhanced photocatalytic activity

Pei

et al. 2018

Sci Rep

The pure, tin (Sn)-doped, lanthanum (La)-doped and Sn/La co-doped titanium dioxide (TiO2) nanomaterials were synthesized using sol-gel method followed by calcination at the temperature of 360 °C, 450 °C and 600 °C, respectively. The structures of the nanomaterials were characterized by X-ray diffraction (XRD), Thermogravimetric (TG), Differential Thermal Analysis (DTA), Scanning Electron Microscopy (SEM), Energy Dispersive Spectrum (EDS), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectrum (XPS), Diffuse Reflectance Spectrum (DRS), Photoluminescence Spectrum (PL), Brunauer-Emmett-Teller Measurements (BET), respectively. The photocatalytic property of the photocatalysts under UV light was evaluated through the degradation of Rhodamine B (RhB). The results show that the anatase-rutile phase transition is promoted by Sn-doping while La-doping retards the phase transition. However, La doping plays a major role in the process of phase transformation. The photocatalytic activity of pure TiO2 is affected by annealing temperature remarkably and the optimal annealing temperature is 450 °C. The photocatalytic activity of TiO2 is enhanced significantly by Sn and La doping at three different temperatures. Sn/La-TiO2 exhibits the highest degradation rates and the fastest reaction rates probably owing to the synergistic effect of Sn4+ and La3+ ions in inhibiting the recombination of photogenerated electron-hole pairs. The formation of extra surface hydroxyl groups and additional surface area are also beneficial for the photocatalytic activity.

Section: Resultssupporting

confidence: 71%

Preparation and characterization of Sn/La co-doped TiO2 nanomaterials and their phase transformation and photocatalytic activity

Pei

et al. 2018

Sci Rep

“…In Figure e, the peaks at 834.2 and 851.4 eV of the 6%L-BOI and 2%A–6%L-BOI samples can be assigned to La 3d 5/2 and La 3d 3/2 , respectively. The satellite peaks of La 3d 5/2 and La 3d 3/2 can be observed at 838.3 and 855.3 eV, respectively, confirming that La was successfully doped as La 3+ in the BOI lattice . As shown in Figure f, the peaks centered at 83.78 and 87.38 eV are ascribed to Au 4f 7/2 and Au 4f 5/2 , respectively, which is in good consistency with the previous report .…”

Section: Resultssupporting

confidence: 89%

Novel Au/La-Bi₅O₇I Microspheres with Efficient Visible-Light Photocatalytic Activity for NO Removal: Synergistic Effect of Au Nanoparticles, La Doping, and Oxygen Vacancy

Zhang

ACS Appl. Mater. Interfaces

et al. 2019

Sphere-like Bi 5 O 7 I (BOI) doped with La (L-BOI) samples were prepared by a solvothermal method followed by calcination at 450 °C for 2 h. Au nanoparticles were loaded on 6% La-doped Bi 5 O 7 I (2%A− 6%L-BOI) microspheres by a room-temperature chemical reduction method. The UV−vis absorption spectra show that the L-BOI and 2%A− 6%L-BOI samples have a strong visible-light absorption in comparison with the pure BOI. The electron paramagnetic resonance results indicate that the number of oxygen vacancies in L-BOI samples is increased with an increasing amount of the La dopant. The band structure of the prepared photocatalysts is investigated by confirming the positions of the valence band (VB) measured by XPS-VB and the Fermi level computed by density functional theory, respectively. NO is selected as a target gaseous pollutant to confirm the influence of La doping and the plasmonic effect of Au nanoparticles on the photocatalytic activity of BOI microspheres. The 2%A−6%L-BOI sample exhibits an enhanced photocatalytic performance compared to BOI, L-BOI, and A-BOI photocatalysts under visible-light irradiation. Interestingly, the 2%A−6%L-BOI sample also can reduce the amount of intermediate NO 2 during the NO removal process. The enhanced photocatalytic efficiency of the 2%A−6%L-BOI photocatalyst is profited from the synergy of La-ion doping, oxygen vacancy, and the surface plasmon resonance effect of Au nanoparticles. Based on the results of trapping experiments and electron spin resonance spectroscopy tests, h + , e − , and • O 2 − were involved in the NO oxidative removal.

“…The shake-up satellite peaks of La 3d 5/2 and La 3d 3/2 are located at 838.11 eV and 854.90 eV. 44 Apparently, LSTBM7 possesses a higher binding energy for La 3d 5/2 , La 3d 3/2 , shake-up satellite peaks of La 3d 5/2 and La 3d 3/2 as 833.92 eV, 851.02 eV, 838.39 eV and 855.04 eV, respectively. Fig.…”

Section: Elemental Valence State Analysismentioning

confidence: 89%

Photoreduction properties of novel Z-scheme structured Sr_0.8La_0.2(Ti_1−δ⁴⁺Ti_δ³⁺)O₃/Bi₂MoO₆ composites for the removal of Cr(vi)

et al. 2021