CHEMICAL ENGINEERING JOURNAL
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2021
·
IF 13.273
Yiwen Zhong,Kaimin Shih,Zenghui Diao,Gang Song,Minhua Su,Li'an Hou,Diyun Chen,Lingjun Kong
Recently, a lot of attentions were paid on sulfate (SO 4 - ∙) and hydroxyl (∙OH) radicals-based advanced oxidation processes in degradation of fluoroquinolone antibiotic due to their favorable oxidation potential. This work reported an integrated peroxymonosulfate (PMS) activation process by coupling ZnFe 2 O 4 (ZFO) with energy-saving LED for degradation and defluorination of levofloxacin (LEV). The LEV degradation efficiency reached 88.52 % within 180 min in the ZFO-500/LED/PMS system, which was higher than those of other activation systems. Both SO 4 - ∙ and ∙OH were generated in the integrated ZFO-500/LED/PMS system by the photo-generated electrons and holes activation of PMS under the LED irradiation. The recombination of photo-generated electrons and holes was reduced. Plenty of ∙O 2 – and 1 O 2 were produced contributing to LEV degradation. The possible degradation pathways and mechanisms were proposed. This study presented a promising LED-assisted PMS activation process by ZnFe 2 O 4 for antibiotic degradation.
研究领域:
环境科学
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化学工程
·
水处理
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DOI
高影响因子
Laser & Photonics Reviews
·
2024
·
IF 9.8
Ting Gong,Yang Yang,Tongtong Xuan,Wenhao Bai,Haorui Dong,Tianliang Zhou,Rong-Jun Xie
Quantum dot (QD) color conversion films (QD-CCFs) are used in ultrahigh definition (UHD) Mini-LED backlit displays due to their narrow band emission and high color purity. However, their poor light conversion efficiency (LCE) leads to greater film thickness and thus high cost. Herein, this study proposes a local light field control strategy to enhance the LCE of QD-CCFs using high-refractive BN nanosheets. The LCEs of the green and red QD-CCFs can increase from 29.9% and 34.8% to 67.4% and 91.0% after adding BN nanosheets, respectively. Combining the experimental data with the finite-difference time domain (FDTD) simulations, the enhanced LCEs can be attributed to observably increased blue light absorption and improved light extraction efficiency of the light emitted from QDs. The white Mini-LEDs, prepared by integrating the optimized QD-CCFs containing BN nanosheets with blue Mini-LED chips, show a high luminous efficiency of 70.2 lm W −1 , a high external quantum efficiency of 36.2%, and a wide color gamut of 96.3% Rec . 2020 standards. This work provides an interesting idea for designing high-efficiency QD-CCFs toward low-cost UHD Mini-LED backlit displays.
研究领域:
光学材料
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显示技术
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DOI
高影响因子
Silicon
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2020
·Vol. 12
·期 12
·3005-3013
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IF 1.499
Pan Zhaoqun,Zeng Kelin,Huang Bingsheng,Zhu Liqiang
The oligosiloxane resins were synthesized through hydrolytic sol-gel reaction and remained many hydroxyl groups, which did great harm to the curing process and resulted in poor performance of the cured products. In previous works, epoxy-modified silicone resins were synthesized by dealcoholization, a reaction between 3-glycidoxypropylmethyldimethoxysilane and terminal hydroxyl groups in phenyl silicone resins. Although this method eliminated the hydroxyl groups, it caused a large loss of vinyl groups inevitably and a poor stability of cured products. In this study, methyltrimethoxysilane (MTMS) was used to eliminate hydroxyl groups containing in vinyl methyl phenyl silicone resins, which were synthesized through hydrolytic sol-gel reaction. Most of residual hydroxyl groups were deleted effectively and the great loss of vinyl groups were avoided in the dealcoholization reaction. Then, the methyl phenyl silicone materials were fabricated by hydrosilylation reaction between the synthesized vinyl methyl phenyl silicone resins and hydrogen-containing ones. The cured silicone materials showed excellent optical performance (~ 89.1% at 450 nm) and good adhesion performance. In addition, due to less vinyl loss in the vinyl methyl phenyl silicone resins, the cured methyl phenyl silicone materials exhibited higher cross-linking density, better thermal resistance (5% mass loss at 435 °C) and better mechanical properties (50 shore D) compared with the epoxy-modified phenyl silicone materials. The lumen depreciation (working 168 h at 50 mA) and reflow soldering tests further demonstrated the methyl phenyl silicone materials possessed good thermal stability. These results indicated that the methyl phenyl silicone materials could be used as a LED encapsulant with a good performance.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Polymer Chemistry
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2017
·Vol. 8
·期 9
·1579-1588
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IF 5.375
Zhiquan Li,Weizhen Shen,Xiaoya Liu,Ren Liu
Simultaneous thiol-based hybrid photopolymerization is an efficient and versatile tool to prepare interpenetrating polymeric networks. A highly active photoinitiator is essential for an efficient simultaneous hybrid reaction. In this paper, several unimolecular photoinitiators, which contain thioxanthone derivatives as chromophores as well as free radical generators, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as a latent alkaline species, were straightforwardly prepared in two steps. The photolysis study indicated that under 405 nm LED light irradiation, the photoinitiators can produce free radicals and a strong base simultaneously via a photodecarboxylation mechanism. The generated active species are highly efficient in catalyzing thiol–yne–epoxy hybrid polymerization without post-exposure baking and the properties of the hybrid network can be tailored by adjusting the compositional ratios of the formulations. The photocured materials using unimolecular photoinitiators exhibit superior thermal and mechanical properties compared to those prepared using a bimolecular initiation system from the literature. The presented strategy to realize simultaneous thiol–yne–epoxy hybrid photopolymerization shows potential for the fabrication of optical devices with enhanced refractive index and improved mechanical properties.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Journal of Environmental Sciences
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2022
·
IF 6.796
Jing Deng,Anhong Cai,Xiao Ling,Qian Sun,Tianxin Zhu,Qingsong Li,Xueyan Li,Weizhu Chen
As an active metabolite of venlafaxine and emerging antidepressant, O-desmethylvenlafaxine (ODVEN) was widely detected in different water bodies, which caused potential harm to human health and environmental safety. In this study, the comparative work on the ODVEN degradation by UV (254 nm) and UV-LED (275 nm) activated sodium percarbonate (SPC) systems was systematically performed. The higher removal rate of ODVEN can be achieved under UV-LED direct photolysis (14.99%) than UV direct photolysis (4.57%) due to the higher values of photolysis coefficient at the wavelength 275 nm. Significant synergistic effects were observed in the UV/SPC (80.38%) and UV-LED/SPC (53.57%) systems and the former exhibited better performance for the elimination of ODVEN. The degradation of ODVEN all followed the pseudo-first-order kinetics well in these processes, and the pseudo-first-order rate constant ( k obs ) increased with increasing SPC concentration. Radicals quenching experiments demonstrated that both ·OH and CO 3 · − were involved in the degradation of ODVEN and the second-order rate constant of ODVEN with CO 3 · − (1.58 × 10 8 (mol/L) −1 sec −1 ) was reported for the first time based on competitive kinetic method. The introduction of HA, Cl − , NO 3 − and HCO 3 − inhibited the ODVEN degradation to varying degrees in the both processes. According to quantum chemical calculation, radical addition at the ortho-position of the phenolic hydroxyl group was confirmed to be the main reaction pathways for the oxidation of ODVEN by ·OH. In addition, the oxidation of ODVEN may involve the demethylation, H-abstraction, OH-addition and C-N bond cleavage. Eventually, the UV-LED/SPC process was considered to be more cost-effective compared to the UV/SPC process, although the UV/SPC process possessed a higher removal rate of ODVEN.
研究领域:
环境科学
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水处理工程
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化学动力学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Xue Bai,Zongqing Jin,Guanjun Xiao,Bo Zou,Qingqin Ge,Nannan Shi,Liwei Jiang,Cheng Sun,Tao Xiong,Yinan Zhang
Lead-free halide double perovskite (HDP) materials have become one of the hot spots due to their remarkable photoelectric properties, including broadband emission due to self-trapped excitons from soft lattice and strong exciton-phonon coupling. However, the optical and optoelectronic properties are hampered in the visible and infrared region, because of a wide or indirect band gap in metal HDPs. So far, doping lanthanide ions is an efficient method to modify the optical properties of HDP materials. Here, we have successfully synthesized dysprosium-based double perovskite (Cs x Rb 3-x DyCl 6-x I x ) crystals through a straightforward hydrothermal method. A very broad band emission covering almost the whole visible spectrum from 400 nm to 700 nm is fulfilled, resulting in a strong white light emission. Further, the hue of the white light can finely be adjusted, via tuning the excitation wavelength. High pressure-induced luminescence enhancement has also been demonstrated. Based on the Cs x Rb 3-x DyCl 6-x I x crystals, we have also fabricated a series of white light-emitting diodes, with the color coordinates of (0.33, 0.33), illustrating its great potential in the solid-state lighting applications. The dysprosium-based double perovskite studied in this work offers us a nice choice for designing HDP-based white light emitting devices.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
Advanced Materials Technologies
·
2022
·Vol. 7
·期 11
·2200320
·
IF 8.856
Shihai Miao,Yanjie Liang,Yan Zhang,Dongxun Chen,Xiao-Jun Wang
Blue light-emitting diode (LED) pumped short-wave infrared (SWIR; 900–1700 nm) emitters are providing new solutions in the design of portable and cost-effective infrared light sources for medical, surveillance, and spectroscopy applications by taking advantage of converter technology. However, desirable blue-light-excitable SWIR-emitting phosphors with a peak wavelength longer than 1000 nm are lacking. Herein, a promising broadband SWIR phosphor is designed and developed by incorporating Cr 3+ -Ni 2+ ion pairs into LiMgPO 4 host. Upon 450 nm blue light excitation, the as-synthesized LiMgPO 4 :Cr 3+ ,Ni 2+ phosphor exhibits a broad and intense SWIR emission spanning from 1100–1600 nm with peak wavelength at 1380 nm and a full width at half maximum of 273 nm due to the efficient energy transfer from Cr 3+ to Ni 2+ . Moreover, phosphor-converted SWIR LED prototype device based on the combination of 450 nm blue LED chip and the optimized phosphor is fabricated as a new type of broadband illuminator covering the SWIR waveband, delivering a maximum radiant power of ≈2.7 mW at 120 mA driving current. Benefiting from the distinct spectral characteristics of SWIR light, the practical relevance of the fabricated SWIR illuminator is demonstrated in covert information identification and night vision lighting.
研究领域:
材料科学
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光学工程
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光电子技术
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DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 8
·2401-2407
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IF 6.641
Yong Liu,Zhi Zhou,Lin Huang,Mikhail G. Brik,Shuaichen Si,Litian Lin,Tongtong Xuan,Hongbin Liang,Jianbei Qiu,Jing Wang
Narrow-band red-emitting fluoride phosphors for wide color gamut LED backlights have evoked considerable attention, due to their fascinating optical properties. Unfortunately, poor moisture resistance often restricts their further applications in optoelectronics. Herein we developed a Cs2SiF6:Mn4+ red phosphor using a low-temperature co-precipitation method and passivating it by using H2O2. The phosphor shows a very high external quantum efficiency (EQE) of ∼85% and exhibits excellent moisture stability retaining 74% of its emission intensity after being exposed to high temperature (85 °C) and high humidity (85%) (HTHH) for 168 h. Finally, the high brightness white LED devices combined with the passivated Cs2SiF6:Mn4+ exhibit high luminous efficacy of 133 lm W−1 and wide color gamut (∼84.7% NTSC). The results demonstrate that the passivated Cs2SiF6:Mn4+ with high EQE and excellent moisture-resistance is promising as a narrow-band red emitting phosphor for wide color gamut LED backlights.
研究领域:
材料科学
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光电技术
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光子学
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产品关联
DOI
高影响因子
Nano Research
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2020
·Vol. 14
·期 3
·628-634
·
IF 8.183
Zhang Xinsu,Chen Yujuan,Lian Linyuan,Zhang Zizhen,Liu Yixuan,Song Li,Geng Chong,Zhang Jianbing,Xu Shu
Infrared lead chalcogenide quantum dots (QDs) suffer fast degradation due to the easy oxidation of surface chalcogen atoms. Here, we report a trioctylphosphine-mediated surface passivation method to improve the air stability of PbS QDs. Surface mechanism study reveals an in situ surface reaction, which leads to site-selective passivation of surface S atoms with lead mono-carboxylate. The surface capping motif sufficiently protects PbS QDs from oxygen and improves their stability as well as quantum efficiency regardless of the QD size and original ligands on surface cations. The modified PbS QDs display no obvious fluorescence quenching and surface oxidization after 30 days of air exposure. The robust surface capping also provides high compatibility of PbS QDs with polymers for optoelectronic device fabrication. The near-infrared LEDs based on the modified PbS QDs display a slight degradation of only 1.47% from the maximum intensity after continuous operation in air for 250 hours (lifetime > 10,000 h) at 0.5 W/cm 2 power density, indicating the surface passivation route is promising strategy for promoting practical optoelectronic application of PbS QDs.
研究领域:
材料科学
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光电技术
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DOI
高影响因子
Materials
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2017
·Vol. 10
·期 11
·1242
·
IF 2.654
Yangyang Xie,Chong Geng,Yiqun Gao,Jay Guoxu Liu,Zi-Hui Zhang,Yonghui Zhang,Shu Xu,Wengang Bi
In this report, to tackle the thermal fluorescent quenching issue of II-VI semiconductor quantum dots (QDs), which hinders their on-chip packaging application to light-emitting diodes (LEDs), a QD-ZnS nanosheet inorganic assembly monolith (QD-ZnS NIAM) is developed through chemisorption of QDs on the surface of two-dimensional (2D) ZnS nanosheets and subsequent assembly of the nanosheets into a compact inorganic monolith. The QD-ZnS NIAM could reduce the thermal fluorescent quenching of QDs effectively, possibly due to fewer thermally induced permanent trap states and decreased Förster resonance energy transfer (FRET) among QDs when compared with those in a reference QD composite thin film. We have demonstrated that the QD-ZnS NIAM enables QDs to be directly packaged on-chip in LEDs with over 90% of their initial luminance being retained at above 85 °C, showing advantage in LED application in comparison with conventional QD composite film.Keywords:quantum dots;nanosheet;assembly;thermal stability
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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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Yufan Wei,Qianxing Huang,Shijie Yu,Qiyue Shao,Jianqing Jiang
The K2SiF6:Mn4+ (KSFM) phosphor featuring efficient ultranarrow red emissions is an outstanding candidate for white light-emitting diode (WLED) applications. However, poor moisture resistance seriously affects its application performance. In this study, a two-step surface reconstruction strategy is proposed to dramatically enhance the moisture resistance of commercially available KSFM phosphors, involving treatment with H2NbF7 and subsequent hydrothermal treatment. The modified KSFM phosphor exhibits a high internal quantum efficiency (IQE) of 98.9% after the two-step surface treatment. Meanwhile, nearly 100% of the initial emission intensity is retained for the modified KSFM phosphor even after aging in high temperature (85 °C) and high relative humidity (85% RH) environments for 6 days, in sharp contrast to only 18.6% retention for the original KSFM phosphor. The relative emission intensity of the modified KSFM remains at 98.9% even after being immersed in water for 6 h. Additionally, the phosphor-converted LED fabricated with the modified KSFM phosphor demonstrated excellent long-term stability, retaining up to 97.9% of initial luminous efficacy after aging under 85 °C and 85% RH conditions for 500 h. The moisture-resistance mechanism is elucidated on the basis of spectroscopic analysis as well as structural and compositional characterization of the phosphor surface layer, which can be attributed to the formation of a robust Mn4+-rare shell with high crystalline quality following this two-step surface treatment. The findings contribute to the performance improvements of KSFM phosphors for industrial applications.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
PubMed
高影响因子
Laser & Photonics Reviews
·
2024
·
IF 9.8
Ying Li,Shuangqiang Fang,Qiangqiang Zhu,Shuxing Li,Bo Liu,Fu Feng,Rongjun Xie,Le Wang
Sunlight like optical source is the primary objective of healthy lighting. In contrast, achieving full spectrum lighting with high stability remains challenging, mostly due to the scarcity of purple chip-pumped cyan-green phosphors and their inherent emission instability. In this study, a novel strategy is presented that realizes simultaneous enhancements in both humidity stability (increased by 2.9 times) and luminescence quantum efficiency (enhanced by 1.5 times) for cyan-emitting Sr 3 AlO 4 F:Ce 3+ phosphor by employing Si/N doping. Theoretical modelling shows that these improvements are attributed to the regulation of energy bands and structural rigidity as well as modulation of the ionicity of chemical bonds. Furthermore, blending the other violet chip-pumped phosphors, sun-like LEDs that accurately replicate solar spectra in different times of the day with an optimal color rendering index of 99 is successfully engineered. Moreover, the universality of this strategy on other oxyfluoride phosphors has also been validated. This groundbreaking outcome offers a practical solution to overcome the inherent luminescence stability limitations in oxyfluoride phosphors, thus catalyzing the application of these cyan-green candidates in sun-like LED lighting.
研究领域:
材料科学
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光学工程
✓ 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）