DYES AND PIGMENTS
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2017
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IF 3.473
Yunjian Wang,Wanying Wu,Xianliang Fu,Mingzhu Liu,Jing Cao,Congying Shao,Shifu Chen
This work explores the phase transition and its impact on photoluminescent properties of metastable scheelite-type, with and without Eu 3+ doped, CdWO 4 nanophosphors. A series of scheelite structure CdWO 4 :xEu 3+ (x = 0, 0.025, 0.05, 0.075, 0.10) samples were synthesized using a simple solvothermal method. The X-ray diffraction results indicate that the prepared samples were single phase in a tetragonal scheelite-type structure, and completely transformed into pure monoclinic wolframite structure after sintering at 450 °C for 2 h. It was revealed by Rietveld analysis that Eu 3+ doping induced a lattice contraction of both scheelite and wolframite CdWO 4 structures. The impact of Eu 3+ doping on the crystal structure and the band structure were further probed by FT-IR, Raman and UV–Vis spectroscopy. SEM images show that the morphology of the prepared samples also changed in the phase transition and the Eu 3+ doping processes. All samples showed a broad multi-color luminescence emission in the range from 400 to 640 nm under 280 nm excitation. The relative intensities of the blue-green emission originated from CdWO 4 matrix and the red emission ascribed to Eu 3+ can be regulated by both the crystal structure and Eu 3+ doping levels. The energy transfer process between WO 4 groups in scheelite structure CdWO 4 and WO 6 groups in wolframite structure CdWO 4 and Eu 3+ was discussed in detail based on the photoluminescent excitation and emission spectra. The synthetic approach reported here allows the control over CdWO 4 polymorphs and this kind of luminescent material has wide applications in white-LED, chemosensors and bioimaging .
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2023
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IF 3.9
Meiting Li,Bo Chen,Chi Zhang,Xuejiao Wang,Fufa Wu,Rongda Zhao
Tartrate (Tar 2− ) was originally employed as a chelating/structure-directing agent for hydrothermal synthesis of CdWO 4 :Yb 3+ ,RE 3+ (RE = Ho and Er) micro/nanocrystallites, followed by calcination at 700 °C for 2 h. It was clearly demonstrated that Tar 2− restricted the exposed ab planes and 3D self-assembly of microplates, resulting in ∼50 nm sized nanoparticles . Up-/down-conversion (UC/DC) photoluminescence were revealed to be strongly size dependent. Under 978 nm pump laser excitation, flower-like assembly was found to exhibit the stronger UC emissions of Ho 3+ and Er 3+ , among which two CdWO 4 :Yb 3+ ,Ho 3+ phosphors generated orange-yellow fluorescence via three-photon processes, while CdWO 4 :Yb 3+ ,Er 3+ microflowers and nanoparticles showed yellowish-green and pale green colors, respectively. Moreover, nanoparticles intensified the dominant green DC emissions of Ho 3+ and Er 3+ by ∼3 and 2 times, implying the pivotal roles of morphology engineering in tunable photoluminescence . This research may provide insights into crystallite/architecture engineering and luminescence optimization for near-infrared response solar cells and solid-state lighting.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2021
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IF 4.464
Siyu Chen,Pan Liu,Yang Li,Mengyi Zhu,Yuan Dang,Yuanzhen Zhou
Rare earth elements Er doped CdWO 4 (Er-CdWO 4 ) nanorods were successfully prepared. The morphology, crystal structure, chemical environments and electrochemical properties of Er-CdWO 4 nanomaterials were regulated by changing the doping amount of Er. Scanning electron microscope (SEM) and transmission electron microscopy (TEM) have shown that the introduction of moderate content of Er could optimize the morphology of CdWO 4 . X-ray diffraction (XRD) results suggested that the larger Er ions partially replaced the Cd ions in CdWO 4 nanocrystals and produced favorable lattice gaps and defects around the unit cell. The high-resolution X-ray photoelectron spectroscopy (XPS) of O 1 s and the enhanced peak intensity in electron spin resonance (EPR) declared that the doping of Er generated more oxygen vacancies in Er-CdWO 4 . Based on the physico-chemical characterizations, 0.5 wt% Er-CdWO 4 was confirmed to be the best electrocatalyst within the tested samples, which exhibited the fastest electron transfer performance and the strongest electrocatalytic capacity to BPA. Taking the low-cost and simply prepared Er-CdWO 4 with the optimal content of Er as the electrode modifier, a novel electrochemical sensor (Er-CdWO 4 /CPE) for BPA has been constructed for the first time, which exhibited the wide linear range from 0.01 to 6 μM and the limited detection of 0.003 μM, respectively. Moreover, satisfactory reproducibility, stability and anti-interference performance were also achieved on Er-CdWO 4 /CPE. Meanwhile, the proposed sensor successfully realized the determination of BPA spiked in local tap water samples.
研究领域:
材料科学
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环境科学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
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2024
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IF 4.9
Pengfei Yu,Yuyin Wu,Anqi Liu,Mati Ullah Khan,Jun Yang,Jiaqi Cui,Shun Wang,Jiawen Liu,Anqi Chu,Ling Kong,Zhiwei Chen
Ochratoxin A (OTA) is a kind of mycotoxin. It widely exists in all kinds of mammals and has teratogenicity and cytotoxicity. In this paper, a label-free photoelectrochemical (PEC) aptamer sensor based on bismuth oxyiodide/cadmium tungstate (BiOI/CdWO 4 ) was designed to detect OTA. The BiOI/CdWO 4 heterojunction is an excellent optoelectronic active material with remarkable chemical stability. AgNO 3 and Na 2 S were selected to grow in situ to form Ag 2 S quantum dots, which were sensitized to enhance the absorption of visible light and promote the generation of photocurrent. In this system, with the increasing of OTA concentration, the photoelectric signal intensity reduces as the specific binding with aptamer. When the concentration of OTA is between 0.01 ng/mL and 50.00 ng/mL, the linear equation is I (μA) = 48.95 – 10.276 lg c ( c OTA , ng/mL), R 2 = 99.281, and the detection limit is 0.823 pg/mL. The newly designed PEC aptamer sensor has exceptional stability, sensitivity, and reproducibility, making it capable of detecting OTA effectively and sensitively.
研究领域:
食品安全检测
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分析化学
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生物传感技术
✓ 已验证
产品关联
DOI
高影响因子
NANO
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2022
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IF 1.438
Canguo Li,Qiying Zhu,Meng Jiang,Huiqin Chang,Liguo Zhao,Ling Kong,Zhiwei Chen,Jun Wang,Hongyun Tian
Cow milk is an important source of protein, but it is also a food that can cause allergies. In this research, a novel photoelectrochemical immunosensor based on CdWO 4 –CdS type-II heterojunction was constructed for the detection of allergen α -lactalbumin ( α -Lac) in milk. CdWO 4 –CdS heterojunction was synthesized by one-step hydrothermal method. Compared with pure CdWO 4 , the CdWO 4 –CdS heterojunction significantly improved the photocurrent intensity. The polydopamine (PDA) was used as a crosslinking agent to couple basis materials and biomolecules. Ascorbic acid was used as an efficient electron donor to eliminate the photo-generated holes and inhibit the recombination of photo-generated electrons and holes. Under the optimum experimental conditions, the photocurrent intensity reduced linearly with the logarithm of α -Lac concentration ranging from 0.001 ng ⋅ mL − 1 to 10 ng ⋅ mL − 1 and the limit of detection was 0.17 pg ⋅ mL − 1 . The constructed photoelectrochemical immunosensor exhibited excellent stability, selectivity and reproducibility, which provided a novel ideal for sensitive detection of α -Lac and shed light on monitoring of other allergenic proteins in foods.
研究领域:
分析化学
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食品科学
·
生物技术
✓ 已验证
DOI
高影响因子
TALANTA
·
2024
·
IF 5.6
Yuhui Qiu,Minghui Huang,Xiaoqian Sun,Yilin Wang,Kunxiang Deng,Zhifang Liu,Yixi Xie,Pengcheng Zhao,Junjie Fei
As an essential chemical intermediate, catechol (CC) residues may have adverse effects on human health. Herein, an effective and facile photoelectrochemical sensor platform based on MgIn 2 S 4 /CdWO 4 composite is constructed for monitoring CC. MgIn 2 S 4 increases light absorption range and activity, while CdWO 4 enhances photoelectronic stability, and the type-II heterojunction formed can significantly enhance photocurrent response. Due to the autoxidation process, CC is converted into oligomeric products, which increase the spatial site resistance and attenuate the overall photocurrent response. It is worth noting that the cauliflower-like structure of MgIn 2 S 4 can provide a large specific surface area , and the presence of Mg 2+ promotes autoxidation , thus providing a suitable condition for detecting CC. Under optimal conditions, the MgIn 2 S 4 /CdWO 4 /GCE photoelectrochemical sensor has a prominent linear relationship in the range of CC concentration from 2 nM to 7 μM, with a limit of detection of 0.27 nM. With satisfactory selectivity, excellent stability, and remarkable reproducibility, this sensor provides a crucial reference value for effectively and rapidly detecting pollutants in environmental water samples.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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