CRYSTAL GROWTH & DESIGN
·
2017
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IF 4.055
Meiqi Chang,Yanhua Song,Jie Chen,Lei Cui,Ye Sheng,Zhan Shi,Haifeng Zou
SiO2@TiO2:Eu3+ core–shell structure was synthesized by a surfactant-free solvothermal method, and its luminescence intensities were increased through a coating SiO2 layer. Furthermore, SiO2@TiO2:Eu3+@SiO2 core double-shell structures with different coating thicknesses have been prepared to examine the relationship between luminescence intensity and thickness. In addition, luminescence enhancement mechanisms including the surface repair effect and excitation/emitted light absorption effect were proposed. Moreover, the luminescence properties and photocatalytic behaviors of SiO2@TiO2:Eu3+ core–shell structure and its derivatives SiO2@TiO2:Eu3+ yolk–shell structure and TiO2:Eu3+ hollow structure have been investigated in detail. It is worth mentioning that yolk–shell and hollow structures could be obtained by changing the order of the calcination and etching process of the SiO2@TiO2:Eu3+ core–shell structure. Herein, the hollow structure showed the highest luminescence intensity, and the core–shell structure exhibited excellent photocatalytic efficiency for the degradation of methyl orange.
研究领域:
材料科学
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光学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 53
·30790-30796
·
IF 3.049
Haoyang Zou,Lan Wang,Huaizhi Tao,Yi Liu,Meiqi Chang,Shiyu Yao
Recently, polyacrylamide (PAM) has been widely used in polymer flooding technology to enhance oil recovery and oil production. However, the difficulty in removing hydrolysed PAM (HPAM) from wastewater still seriously blocks the further application of polymer flooding in the oilfields. Herein, we demonstrate the preparation of SiO2@TiO2:Eu3+@TiO2 core double-shell microspheres (STT) through a two-step solvothermal and sol–gel coating strategy. The as-prepared STT exhibits an ideal photocatalytic activity for the photodegradation of HPAM. More importantly, by using STT as the model, the correlation between fluorescence intensity and photocatalytic activity of the photocatalysts is investigated. The results suggest their oppositional relationship. Since many kinds of photocatalysts are utilized in the degradation of organic pollutants, it is believed that our work will not only promote the development of photocatalysis in the field of oil extraction, but also offer a convenient method for evaluating the photocatalytic activity of the photocatalysts.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Photonics and Nanostructures-Fundamentals and Applications
·
2025
·
IF 2.9
Xin Li,Yangyang Guo,Huibing Mao,Ye Chen,Jiqing Wang,Weifeng Fang
The TiO 2 :Eu 3+ inverse opals have the anatase structure and can be analyzed approximately by the two-dimensional photonic crystal. The emission spectra of the Eu 3+ ions in the TiO 2 :Eu 3+ inverse opal demonstrate that the inverse opal has significant manipulation effect on the emission of the Eu 3+ ions. With the polystyrene (PS) microsphere size of 300 nm, the emission intensity ratio of the magnetic dipole transition 5 D 0 → 7 F 1 to the electric dipole transition 5 D 0 → 7 F 2 increases by about 4.9 times in the TiO 2 :Eu 3+ inverse opal in comparison with the reference TiO 2 :Eu 3+ nanomaterials sample, meanwhile the electric dipole emission 5 D 0 → 7 F 4 at 695 nm also increases significantly. With the deviation of the PS microsphere size, the above manipulation effect also decreases. The theoretical analysis implies that the above manipulation is mainly due to the forbidden photonic band of the TE mode in the TiO 2 :Eu 3+ inverse opal, which results in the decrease of the electric local density of state in the forbidden photonic band and the decrease of the emission 5 D 0 → 7 F 2 , on the contrary, the corresponding emissions 5 D 0 → 7 F 1 and 5 D 0 → 7 F 4 will increase.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2023
·
IF 5.5
Zhang Chen,Wang Minqiang,Shi Jindou,Wang Junnan,Da Zheyuan,Zhou Yun,Xu Youlong,Gaponenko Nikolai V.,Bhatti Arshad Saleem
The inherent single narrow emission peak and fast anion exchange process of cesium lead halide perovskite CsPbX3 (X = Cl, Br, I) nanocrystals severely limited its application in white light-emitting diodes. Previous studies have shown that composite structures can passivate surface defects of NCs and improve the stability of perovskite materials, but complex post-treatment processes commonly lead to dissolution of NCs. In this study, CsPb(Cl/Br)3 NCs was in-situ grown in TiO2 hollow shells doped with Eu3+ ions by a modified thermal injection method to prepare CsPb(Cl/Br)3/TiO2:Eu3+ composites with direct excitation of white light without additional treatment. Among them, the well-crystalline TiO2 shells acted as both a substrate for the dopant, avoiding the direct doping of Eu3+ into the interior of NCs to affect the crystal structure of the perovskite materials, and also as a protection layer to isolate the contact between PL quenching molecules and NCs, which significantly improves the stability. Further, the WLED prepared using the composites had bright white light emission, luminous efficiency of 87.39 lm/W, and long-time operating stability, which provided new options for the development of perovskite devices.
研究领域:
材料科学
·
光电技术
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2017
·
IF 5.951
Meiqi Chang,Yanhua Song,Jie Chen,Lei Cui,Zhan Shi,Ye Sheng,Haifeng Zou
A novel multifunctional core–shell, yolk–shell SiO2@TiO2:Eu3+/Sm3+ and hollow TiO2:Eu3+/Sm3+ structures were successfully synthesized. The relationship between morphology/ions doping and multifunctional properties including photoluminescence and photocatalysis has been discussed in detail for the first time using systematic characterization techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL), ultraviolet–visible light (UV-vis) analysis, Fourier transform infrared (FT-IR) spectroscopy, Brunauer–Emmett–Teller (BET) surface area analysis, and X-ray photoelectron spectroscopy (XPS). Upon ultraviolet (UV) excitation, the products show the characteristic red and orange–red emission lines of Eu3+ and Sm3+, respectively. In addition, Judd–Ofelt intensity parameters (Ω2, Ω4) were used to investigate the symmetry and coordination state of Eu3+ ions in the products with different morphologies. The relative luminescence intensities were in the following order: yolk–shell > core–shell > hollow structure. This phenomenon can be ascribed to the unique yolk–shell configuration, which possesses appropriate interior cavity used for multiple reflections and scattering, allowing for more-efficient utilization of the light. Moreover, compared with yolk–shell and hollow structure, the core–shell spheres exhibit excellent photoactivity for the degradation of MO, because the existence of Ti–O–Si bonds increases the surface acidity of the sample, thereby activating the oxidation reaction. In addition, the electron activation in the TiO2 matrix can be facilitated through intermediate oxygen atoms. Moreover, products doped with different rare-earth (RE3+) ions exhibited distinguishable photocatalytic performance. The surfactant-free method provides a promising route toward the development of multifunctional materials for many applications in photocatalysis and PL.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）