Photoluminescence and Photocatalytic Activity of Bi2MoO6:Ln3+ Nanocrystals

2016 ◽  
Vol 16 (4) ◽  
pp. 3781-3785 ◽  
Author(s):  
Li Feng ◽  
Mingxia Li ◽  
Kai Pan ◽  
Rong Li ◽  
Naiying Fan ◽  
...  

Sheet-like Bi2MoO6:Ln3+ nanocrystals were synthesized by a hydrothermal method. The crystalline size of Bi2MoO6:Ln3+ (Ln = Eu and Gd) nanocrystals changes gradually with the increasing of Ln3+ content in the reaction solutions. The photoluminescence properties of Bi2MoO6:Ln3+ nanocrystals were investigated in detail. In the emission spectra of Bi2MoO6:Eu3+ nanocrystals the 5D0 →7F2 is much stronger than the 5D0 →7F1 and is the strongest when the excitation is performed at 467 nm. The relative intensity of the transitions from Eu3+ increased with increasing Eu3+ concentrations, up to about 50 mol%, and then decreased abruptly. In the excitation spectra of Bi2MoO6:Eu3+ (30%)/Gd3+ monitored at 618 nm, the 7F0 → 5D2 (∼467 nm) transition is dominating when the Gd3+ concentrations were 10% or 20%. When the Gd3+ concentration was 30%, the 7F0 → 5D1 (∼538 nm) transition is dominating. In addition, the photocatalytic activity of Bi2MoO6:Eu3+ was evaluated by the degradation of rhodamine B (RhB) aqueous solution under simulated solar light. The best photocatalytic performance was observed when the Eu3+ concentration was 1%.

NANO ◽  
2017 ◽  
Vol 12 (03) ◽  
pp. 1750027 ◽  
Author(s):  
Yi Ling Qi ◽  
Xu Chun Song ◽  
Yi Fan Zheng

Novel heterostructure BiOI/BiOIO3 nanocomposites were successfully prepared through a facile deposition method at room temperature. BiOIO3 is a noncentrosymmetric compound that has an internal self-built electric field. BiOI was applied as a visible light absorber to sensitize semiconductors owing to its smallest bandgap. The coupling between BiOIO3 and BiOI can combine their advantages and improve photocatalytic properties. Compared with the single BiOI and BiOIO3, the heterostructure BiOI/BiOIO3 nanocomposites displayed a significantly enhanced photocatalytic activity for the Rhodamine B (RhB) degradation. The enhanced photocatalytic performance is deduced closely related to the formation of BiOI/BiOIO3 heterojunction interface whose presence is regarded to be a favorable factor for the transfer and separation of the photogenerated electrons and holes.


2011 ◽  
Vol 194-196 ◽  
pp. 385-388
Author(s):  
Hong Juan Wang ◽  
Feng Qiang Sun ◽  
Ming Zhong Ren ◽  
Qing Wei Guo

Nanoporous SnO2with high photocatalytic activity has been successfully prepared by a photochemical method, using SnCl2aqueous solution as a precursor. The as-synthesized sample was characterized by XRD, N2 adsorption-desorption and UV-vis. The photocatalytic activity of the sample was evaluated by degrading methylene blue (MB) aqueous solution under the UV light source and was compared with that of the commercial titania (Degussa P25). The results showed that the produced SnO2can degrade MB solution quickly and has comparative photocatalytic performance with P25 for degrading MB. This facile method supplies an effective way to prepare SnO2photocatalyst.


2018 ◽  
Vol 5 (6) ◽  
pp. 172005 ◽  
Author(s):  
Chentao Hou ◽  
Wenli Liu

TiO 2 /TiOF 2 nanohybrids were quickly synthesized through a hydrothermal process using titanium n-butoxide (TBOT), ethanol (C 2 H 5 OH) and hydrofluoric acid as precursors. The prepared nanohybrids underwent additional NaOH treatment (OH-TiO 2 /TiOF 2 ) to enhance their photocatalytic performance. In this paper, the mechanism of NaOH affecting the pathway of transformation from TBOT (Ti precursor) to TiO 2 nanosheets was discussed. The synthesized TiO 2 /TiOF 2 and OH-TiO 2 /TiOF 2 were characterized by field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction pattern (XRD), Fourier infrared spectroscopic analysis (FT-IR), Photoluminescence (PL) emission spectra and UV–visible diffuse reflection spectra (UV–vis DRS). The photocatalytic activity and stability of synthesized samples were evaluated by degradation of methylene blue (MB) under the simulated solar light. The results showed that a larger ratio of TiO 2 to TiOF 2 in TiO 2 /TiOF 2 and OH-TiO 2 /TiOF 2 nanohybrids could allow for even higher MB conversion compared with only TiO 2 nanosheets. NaOH treatment can wash off the F ions from TiOF 2 and induce this larger ratio. The highest efficiency of MB removal was just above 90% in 1 h. Lower electron–hole pairs recombination rate is the dominant factor that induces the photocatalytic performance enhancement of TiO 2 /TiOF 2 nanohybrids. The synthesized OH-TiO 2 /TiOF 2 nanohybrids exhibit great potential in the abatement of organic pollutants.


RSC Advances ◽  
2014 ◽  
Vol 4 (110) ◽  
pp. 64747-64755 ◽  
Author(s):  
Xuefeng Xu ◽  
Man Wang ◽  
Yanyan Pei ◽  
Changchun Ai ◽  
Liangjie Yuan

The micro/nano-structure composite SiO2@Ag/AgCl was employed as a low cost photocatalyst for the degradation of RhB in aqueous solution under visible light irradiation, which exhibited excellent photocatalytic performance and stability.


Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1671 ◽  
Author(s):  
Weike Zhang ◽  
Yanrong Zhang ◽  
Kai Yang ◽  
Yanqing Yang ◽  
Jia Jia ◽  
...  

A silicon dioxide/carbon nano onions/titanium dioxide (SiO2/CNOs/TiO2) composite was synthesized by a simple sol-gel method and characterized by the methods of X-ray diffraction (XRD), scanning electronic microscope (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), Fourier transform infrared (FTIR), thermogravimetric analysis (TG), differential scanning calorimeter (DSC) and UV-Vis diffuse reflectance spectra (UV-Vis DRS). In this work, the photocatalytic activity of the SiO2/CNOs/TiO2 photocatalyst was assessed by testing the degradation rate of Rhodamine B (RhB) under visible light. The results indicated that the samples exhibited the best photocatalytic activity when the composite consisted of 3% CNOs and the optimum dosage of SiO2/CNOs/TiO2(3%) was 1.5 g/L as evidenced by the highest RhB degradation rate (96%). The SiO2/CNOs/TiO2 composite greatly improved the quantum efficiency of TiO2. This work provides a new option for the modification of subsequent nanocomposite oxide nanoparticles.


2018 ◽  
Vol 238 ◽  
pp. 03007
Author(s):  
Xiquan Wang ◽  
Nan Zhang ◽  
Gao Wang

Bi2S3-sensitized BiFO3 (BFO) photocatalyst (Bi2S3/BFO) was successfully synthesized through a facile and environmental ion exchange method between BFO and Thiosurea (H2NCSNH2, TU). The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and UV-vis diffuse reflection spectroscopy (DRS). The obtained Bi2S3/BFO composites showed excellent photocatalytic performance for decomposing Rhodamine B (RhB) compared with pure BFO under visible light irradiation (λ>400nm). 5% Bi2S3/BFO exhibited the highest photocatalytic activity and excessive amount of Bi2S3 would result in the decrease of photocatalytic activity of BFO. The mechanism of enhanced photocatalytic activity was proposed on the basis of the calculated energy band positions.


2013 ◽  
Vol 423-426 ◽  
pp. 163-166 ◽  
Author(s):  
Bao Wei Cao ◽  
Yun Hua Xu

Bi2WO6 doped with iodine ions were synthesized using hydrothermal method and their photocatalytic activities to degrade Rhodamine B (RhB) under visible-light was investigated. The successful incorporation of I ions in Bi2WO6 was proved by XRD and XPS. UV-vis absorption spectra results show that I ion was successfully doped into Bi2WO6 and a red shift for I-doped Bi2WO6 appeared when compared to pure Bi2WO6. The photocatalytic activities of the photocatalysts were evaluated by the decolorization of RhB under visible-light irradiation. The results showed that the photocatalytic activity of I-doped Bi2WO6 was much higher than the undoped Bi2WO6.


2013 ◽  
Vol 760-762 ◽  
pp. 483-486
Author(s):  
Su Wen Li ◽  
Ming Yue

The Eu complexes-Eu (TTA)3phen (TTA: thenoyltrifluoroacetone, phen: 1,10-phenanthroline) were encapsulated, uniformly distributed into the channels of the modified SBA-15 (labeled with MSBA-15), and structurally characterized. The photoluminescence properties of the encapsulated complexes were systematically studied in contrast to the pure complexes. The results indicate that the excitation bands assigned to the π-π* electron transition of the ligands for Eu3+complexes in encapsulated complexes were split into different components, and the5D0-7F0transitions became partly allowed. The emission lines for the5D0-7F2transitions became broader and the relative intensity for different crystal field components varied greatly in comparison to the pure complex. Most importantly, the photostability and thermostability of the emissions improved considerably.


2021 ◽  
Author(s):  
Rui Zhang ◽  
ziyin chen ◽  
Chen Zhao ◽  
Kunlin Zeng ◽  
Lu Cai ◽  
...  

Abstract A novel binary BiSI/Ag2CO3 photocatalyst with excellent visible light-driven photocatalytic performance was prepared. The products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) and electrochemical impedance spectroscopy (EIS). The photocatalytic activity of the samples were evaluated by photocatalytic degradation of rhodamine B(RhB) under the irradiation of visible light. The results showed that the BiSI improves the photocatalytic activity of BiSI/Ag2CO3. Moreover, when the mass ratio of BiSI in BiSI/Ag2CO3 composites was 40%, the as-prepared BiSI/Ag2CO3 composite exhibited the best photocatalytic activity for degrading RhB. Finally, the possible mechanism for photodegradation over the BiSI/Ag2CO3 composites is also proposed.


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