LUMINESCENCE
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2019
·Vol. 34
·期 7
·680-688
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IF 1.691
Yang Liu,Piaopiao Chen,Shan Zheng,Yichen Xing,Chaobiao Huang
In this study, a high fluorescence sensitivity and selectivity, molecularly imprinted nanofluorescent polymer sensor (MIP@SiO 2 @QDs) was prepared using a reverse microemulsion method. 2,4,6-Trichlorophenol (2,4,6-TCP) was detected using fluorescence quenching. Tetraethyl orthosilicate (TEOS), quantum dots (QDs) and 3-aminopropyltriethoxysilane (APTS) were used as cross-linker, signal sources and functional monomer respectively. The sensor (MIP@SiO 2 @QDs) and the non-imprinted polymer sensor (NIP@SiO 2 @QDs) were characterized using infra-red (IR) analysis, X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The selectivity of MIP@SiO 2 @QDs was examined by comparing 2,4,6-TCP with other similar functional substances including 2,4-dichlorophenol (2,4-DCP), 2,6-dichlorophenol (2,6-DCP) and 4-chlorophenol (4-CP). Results showed that MIP@SiO 2 @QDs had better selectivity for 2,4,6-TCP than the other compounds. Fluorescence quenching efficiency displayed a good linear response at the 2,4,6-TCP concentration range 5–1000 μmol/L. The limit of detection (LOD) was 0.9 μmol/L (3σ, n = 9). This method was equally applicable for testing actual samples with a recovery rate of 98.0–105.8%. The sensor had advantages of simple pretreatment, good sensitivity and selectivity, and wide linear range and could be applied for the rapid detection of 2,4,6-TCP in actual samples.
研究领域:
分析化学
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环境科学
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DOI
高影响因子
Journal of Physical Chemistry C
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2021
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IF 4.126
Zhiwei Yao,Chenghao Bi,Jianjun Tian
Quantum dot light-emitting diodes (QLEDs) show great potential in high-definition displays due to their narrow emission and high color purity. However, the imperfect quantum dots (QDs) with high trap density are difficult to be removed from QD solution, which could cause serious nonradiative recombination, thereby suppressing the improvement of QLEDs. Here, we devise a novel chemical filtering strategy with a bidentate coordination to remove the imperfect QDs. The bidentate ligand of ethanolamine (EA) with an amidogen and a carboxyl was directly added into the CdSe/CdS/ZnS core/shell/shell QD solution. Then, uncoordinated sites such as S2– and Zn2+ on the surface of QDs were bonded with the amidogen and carboxyl of EA, respectively, resulting in aggregations of the imperfect QDs with high defect density, which were precipitated from the solution. As a result, the photoluminescence quantum yield (PLQY) of the filtered QD solution increased to 93% because of the decrease in trap density. The size distribution of QDs was also improved after filtration. QLEDs fabricated with filtered QDs show a high external quantum efficiency (EQE) of 15.76% and luminance of 19,640 cd/m2, greater than those of the control devices. This strategy shows a great potential to be used in the large-scale treatment and production of QDs and QLEDs.
研究领域:
材料科学
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纳米技术
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光电子学
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显示技术
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DOI
高影响因子
Nano Energy
·
2022
·
IF 19.069
Kanghong Wang,Yi Tao,Zikun Tang,Daniele Benetti,François Vidal,Haiguang Zhao,Federico Rosei,Xuhui Sun
Colloidal Quantum dots (QDs) are considered promising light harvesters for photoelectrochemical (PEC) hydrogen generation devices due to their size tunable optoelectronic properties. However, the solar-to-hydrogen (STH) efficiency and long-term stability of devices based on QDs are still relatively low, thus limiting the commercial development. These limitations are attributed to the limited absorption range of QDs, unfavorable band energy alignment and photo-oxidation. Here we propose and realize two core/multiple-shell architecture based on CdSe/CdS/ZnS QDs. The shell composition is optimized with gradient layers, forming CdSe/CdSe x S 1−x /CdS/Zn y Cd 1−y S/ZnS core/multiple-shell structures, which reduces the surface traps and defects of QDs and simultaneously suppresses exciton recombination by providing intermediated alloyed interlayers . The PEC device based on a mesoporous TiO 2 sensitized with two types of core/multiple-shell QDs exhibited an outstanding saturated photocurrent density of 20.5 mA/cm 2 for alloyed core/multiple-shell QDs, under one sun illumination (AM 1.5 G, 100 mW/cm 2 ). To our knowledge, this is comparable to the highest value reported so far for the PEC devices based on colloidal QDs. In addition, the as-prepared PEC devices exhibited excellent stability, maintaining ~93.4 % of the initial photocurrent density after 2-hour continuous illumination (100 mW/cm 2 ). This work provides an efficient approach for improving the performance of PEC devices through QDs structure engineering.
研究领域:
材料科学
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纳米技术
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光电化学
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可再生能源
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产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2025
·
IF 5.5
Mingrui Liu,Guangmin Li,Shunsheng Wei,Hongfei Liu,Gaoling Yang
Chiral semiconductor nanocrystals (NCs) represent a promising class of materials for various applications, including biological sensing, photonics, and spin-polarized devices. However, the comprehension of the mechanisms underlying ligand-induced chiroptical effects in NCs has been limited by the constraints of current theoretical and experimental models, particularly those involving simple spherical NCs. In this study, we examined the relationship between optical activity and band structures in core–shell dot-in-rod NCs, specifically CdSe@CdS, ZnSe/CdS@CdS, and ZnSeTe/CdS@CdS dot-in-rod NCs, which were functionalized with chiral ligands. By manipulating the wave function distribution of electrons and holes within the dot-in-rod NCs, we demonstrated through circular dichroism (CD) measurements that a reduction in the number of holes within the synthesized dot-in-rod NCs correlates with a decrease in the g factor. This conclusion was corroborated by theoretical calculations. Furthermore, the fabrication of chiral CdS-Au heterojunctions and the application of electron quenchers revealed that the reduction of the g factor also suggests the significant role of electrons in the generation of chirality. Our findings not only enhance the understanding of the fundamental origins of induced chirality effects in semiconductor NCs but also provide a clear methodology for the design of optimal optically active chiral NCs, thereby paving the way for future applications utilizing chiroptical materials.
研究领域:
纳米材料
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半导体物理
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手性光学材料
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量子点
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光电子学
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表面化学
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理论凝聚态物理
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产品关联
DOI
高影响因子
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