JOURNAL OF RARE EARTHS
·
2024
·
IF 5.2
Ying Li,Jiaqi Ou,Shuangqiang Fang,Jiali Yu,He Lin,Haoliang Cheng,Xiulan Shui,Renjie Xu,Zhijie Ye,Le Wang
Due to the wide and adjustable emission range, Ce 3+ is an indispensable luminous center for full spectrum lighting. However, it needs to be sintered at high temperature in a reducing atmosphere, resulting in difficulty to coexisting with other multivalent activated ions (such as Eu 3+ , Tm 3+ ), which greatly hinders the formation of full spectrum. In this study, a calcium vacancy enhanced self-reduction of Ce 4+ is realized in CaNaSb 2 O 6 F (CNSOF) host under air atmosphere sintering, through which Ce 3+ , Tm 3+ and Eu 3+ coexisting in a single-phase full spectrum phosphor was prepared. Notably, the artificial introduction of a calcium vacancy was designed to verify this self-reduction mechanism. Moreover, the energy transfer kinetics among Tm 3+ , Ce 3+ and Eu 3+ were explored. Finally, combined with a 340 nm UV chip, a full spectrum phosphor-converted light-emitting diode (pc-LED) was fabricated, showing a broad emission range from 400 to 750 nm, Commission Internationale de I’Eclairage (CIE) of (0.3485, 0.3673), Ra of 92 and correlated color temperature (CCT) of 4933 K. Utilizing the variation in emission colors of this phosphor under different UV wavelengths, a dual encryption method combining point character code and fluorescent encryption technique is proposed. This work provides an effective path for Ce 4+ self-reduction to apply in full spectrum pc-LED and information encryption.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2025
·
IF 7.3
Ning Li,Linzi Zuo,Fanchao Xu,Xiaolei Qu,Heyun Fu,Huiting Liu
Cerium sulfide (Ce 2 S 3 ) pigment is an environmentally friendly novel inorganic red-colored metal pigment, representing a potential alternative to traditional heavy metal pigments. In this study, we report concurrent re-precipitation and photo-dissolution of cerium sulfide pigment in a sunlit aquatic phase. Commercial cerium sulfide pigment transforms into its re-precipitation product, CeCO 3 OH, along with the generation of H 2 S gas in its re-precipitation process. Simultaneously, cerium sulfide pigment photo-dissolution results in a significant release of Ce ions. After 4 hours of simulated sunlight irradiation, the particle size of cerium sulfide pigment significantly reduces, and 10.4% of elemental Ce is released into the solution as free Ce ions. The key photo-dissolution mechanism is the oxidation reaction between photogenerated holes and the crystal lattice of the pigment. Cerium sulfide pigment and its re-precipitation product, CeCO 3 OH, can be excited by specific wavelengths in the solar spectrum, mediating the pigment photo-dissolution. UV light shielding can inhibit the cerium sulfide pigment photo-dissolution. Superoxide and hydroxyl radicals are generated during the photoreaction process, in which the hydroxyl radical may oxidize the photo-induced released Ce(III) to Ce(IV) and the re-precipitation-generated H 2 S to SO 4 2- . Our research indicates that commercial cerium sulfide pigment undergoes a series of transformation processes in aquatic environments, potentially posing certain environmental risks.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Yaxin Li,Shiwen Wu,Hongzhi Lu,Shoufang Xu
Organicphosphorus is a ubiquitous pesticide that has potential hazards to human health and environmental well-being. Therefore, the precise identification of residues of organophosphorus pesticides (OPs) emerges as an urgent necessity. A ratiometric fluorescent sensor for the detection of OPs by leveraging the catalytic activities of Ce 3+ and Ce 4+ on the two fluorescent substrates 4-Methylumbelliferyl phosphate (4-MUP) and o -phenylenediamine (OPD) correspondingly was designed. Ce 3+ can not only dephosphorylate 4-MUP to generate 4-methylumbelliferone (4-MU) with blue fluorescence, but it can also react with H₂O₂ to produce Ce 4+ and hydroxyl radicals (·OH), both of which exhibit peroxidase-like activity. These two species can oxidize the colorless substrate OPD into the yellow fluorescent product 2,3-diaminophenazine (DAP). Owing to the inner filter effect, the produced DAP diminishes the blue luminescence of 4-MU. So, with the increase of H 2 O 2 concentration, the blue fluorescence of 4-MU decreased while the yellow fluorescence of DAP increased. A ratiometric fluorescent sensor based on Ce 3+ -4-MUP-OPD triple system was established for H 2 O 2 detection with the fluorescence color of the solution changes from blue to yellow. OPs inhibit the activity of acetylcholinesterase (AChE) and prevent AChE and choline oxidase (ChOx) from acetylthiocholine chloride (ATChCl) to produce H 2 O 2 , thereby OPs can diminish DAP generation and reinstating the blue luminescence of 4-MU. The detection limits of H₂O₂ and OPs using fluorescence spectroscopy are 0.03 μM and 0.59 ng/mL, respectively. However, when coupled with a smartphone color recognition application, the visual detection limits for H₂O₂ and OPs are 9.7 μM and 19.6 ng/mL, respectively. The materials used in this ratiometric sensor are cost-effective and readily available, eliminating the need for material synthesis and simplifying the detection process. Additionally, the sensor integrates with a smartphone color recognition application, further streamlining the detection workflow and enabling real-time data analysis and result feedback. This combination provides a straightforward, efficient and economical solution for monitoring OPs in agricultural products.
研究领域:
分析化学
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环境科学
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食品科学
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产品关联
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2019
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IF 3.78
Ziling Teng,Chunlu Ye,Chenmin Zheng,Fan Chen,Yiya Li,Sili Wen,Jie Cai,Peng Fei
In this study, Ce ions were doped into the crystal lattice of TNTs and bonded to O, which resulted in the generation of CeO 2 and expansion of the lattice defects of TNTs. Then, TNTs and Ce doped TNTs (Ce-TNTs) were coated on the surface of bamboo fibre materials by layer-by-layer self-assembly to refine the flame retardant performance of the materials. Scanning electron micrographs (SEM) and energy disperse spectrum (EDS) analysis indicated that the TNTs and Ce-TNTs were uniformly distributed on the surface of the bamboo fibre materials, and the Ti content reached ∼3.90 wt% and ∼3.70 wt%, respectively. Results from the cone calorimeter test showed that the flame retardant performance of the bamboo fibre materials was enhanced after the TNTs were coated on the surface of the materials (TNTs@Fibre). When Ce-TNTs were used as substitute for TNTs, the flame retardant performance of the Ce-TNTs@Fibre materials was further improved. The TTI and FPI were prolonged to 39.7s and 0.073 m 2 s/kW, and the av-HRR and THR were reduced to 126.9 kW/m 2 and 35.54 MJ/m 2 respectively. Moreover, pSEA, TSP and pSPR were decrease to 292.5 m 2 /kg, 3.70 m 2 and 0.039 m 2 /s. DSC and TG results demonstrated that the TNTs and Ce-TNTs enhanced the both thermostability and thermo oxidative stability of the materials.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2019
·Vol. 166
·期 13
·D638
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IF 3.12
Pengfei Xu,Xiaohong He,Junwei Mao,Yongming Tang
In this paper, Ti/SnO2-Sb/Ce-PbO2 anode is electrodeposited from MSA bath, and the effect of Ce3+ concentration in bath on the phase composition and morphology of lead dioxide electrode is elucidated. It is found that with the addition of 2 mM Ce3+ ion to the bath the Ce-PbO2 anode exhibits highest stability in 0.5 M H2SO4, and cerium exists as Ce (IV) in the PbO2 film. The electrocatalytic activity of lead dioxide anode for phenol removal is slightly enhanced by the inclusion of Ce. The significant improvement in electrocatalytic activity can be achieved by the addition of small amount of Bi3+ ion to the bath containing Ce3+ ion. In this study, electrocatalytic activities of various anodes follow the order: Ce,Bi-PbO2 > Ce-PbO2 > undoped PbO2 > Bi-PbO2.
研究领域:
材料科学
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电化学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 15
·6780-6786
·
IF 3.591
Ling Liang,Zhenghong Zhao,Fanggui Ye,Shulin Zhao
Dopamine (DA) exists as a meaningful neurotransmitter which is extremely useful for the diagnosis of neurological disorders. For this reason, monitoring the levels of DA is greatly important. A facile colorimetric method is described here for measuring DA using tetravalent cerium ions (Ce4+). Inspired by the intrinsic oxidase-like activity of Ce4+, it can directly oxidize the substrate 3,3,5,5-tetramethylbenzidine (TMB) in the presence of oxygen (O2) without requiring hydrogen peroxide (H2O2). Interestingly, when DA is introduced, the catalytic oxidation ability of Ce4+ is significantly enhanced, and a dark blue color of oxidized TMB (oxTMB) can be observed instantly. This boost is benefited from the fact that more superoxide radicals (˙O2−) are generated with the addition of DA. In view of this, a facile approach for colorimetric determination of DA has been realized. Within the range of 6.5–520 nM, the absorption intensity of oxTMB is proportional to the concentration of DA and the detection limit is 2.88 nM. What is more, the detection can be accomplished in 3 min at room temperature, which is extremely important for real-time and rapid bioanalysis. This sensor has been successfully applied to measure DA in biological samples. Such an economical, simple, rapid, and sensitive method shows great potential application prospects in clinical early diagnosis.
研究领域:
分析化学
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神经生物学
·
临床诊断
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产品关联
DOI
高影响因子
PROGRESS IN NUCLEAR ENERGY
·
2022
·
IF 2.461
Pan Tan,Xiaoyan Shu,Mingfen Wen,Lingshuang Li,Yuexiang Lu,Xirui Lu,Shuaipeng Chen,Faqin Dong
Various cerium doped aluminosilicate glass was prepared by a high-temperature melting method using natural granite material as the only origin of the glass substrate . TG-DSC was used to understand the changes of this aluminosilicate material in the melting process. The structure of the glass was systematically studied by X-ray diffraction, scanning electron microscopy, infrared spectroscopy, X-ray photoelectron spectra. This type of aluminosilicate material begins to vitrify at about 1000 °C, and its maximum vitrification degree was obtained at 1500 °C. The structure of the glassy waste forms prepared at this temperature is mainly composed of Q 3 and Q 4 structural units. With the addition of cerium ions, the proportion can even reach 82%. Such good glass integrity makes this type of aluminosilicate glass density and hardness up to 2.89 g cm −3 and 7.80 GPa, respectively. However, the addition of excessive cerium ions destroys the integrity of the network, resulting in that the glass can only carry 17 wt % cerium ions at most. At this point, 55.93% of Ce 4+ ions are reduced to Ce 3+ . In the meantime, cerium ions are evenly distributed in the glass network. This study provides a strategy for the treatment of radioactive waste with similar properties with cerium ions.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2015
·
IF 4.097
Lu Jing Chai,Jin Zhou,Hui Feng,Jing Jing Lin,Zhao Sheng Qian
A convenient and reversible nanoswitch with the assistance of cerium ions based on aggregation and disaggregation of carbon quantum dots was developed to achieve highly sensitive detection of pyrophosphate ions. Two states including aggregation state and disaggregation state corresponding to fluorescence on and off signaling can be readily switched in a reversible way. The aggregation state is resulted from large nanoassembly formed by carbon quantum dots and cerium ions due to their strong complexation affinity. The disaggregation state comes from competitive combination between cerium ion and pyrophosphate ion. The PPi ion severs as the external chemical stimulus to CQDs/Ce(III) nanoassembly, and its quantity is responsive to fluorescence intensity of the sensing system. Quantitative evaluation of PPi in a broad range from 0.3 to 29.7 μM with the detection limit of 0.1 μM can be realized in this way. The PPi detection in human HeLa cells was also assessed, and fluorescence switching between ON and OFF can be readily observed in response to presence and absence of PPi.
研究领域:
分析化学
·
生物传感
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Chemistry
·
2021
·
IF 8.301
Wei Li,Nan Ma,Balaji Devakumar,Xiaoyong Huang
The current commercial white light-emitting diodes (LEDs) are generally based on the combination of blue LED chips and Y 3 Al 5 O 12 :Ce 3+ yellow phosphors. However, because of the lack of red component, such white LED devices exhibit cool white-light emissions with low color rendering index (Ra < 75, R9 < 0). Therefore, it is urgent to discover new blue-light-excitable yellow-emitting phosphors with enhanced red emissions for fabricating high color-quality white LEDs. In the present work, we demonstrate a novel broadband yellow-emitting CaGd 2 HfScAl 3 O 12 :Ce 3+ garnet phosphor for blue-light-excited white LEDs with improved color rendering index. The as-prepared CaGd 2 HfScAl 3 O 12 :Ce 3+ garnet phosphor possesses a cubic structure with Ia 3 ¯ d space group, and the unit cell parameters of the representative CaGd 2 HfScAl 3 O 12 :2%Ce 3+ phosphor are a = b = c = 12.450 Å, α = β = γ = 90°, and V = 1,929.59(4) Å 3 . Impressively, we find that the CaGd 2 HfScAl 3 O 12 :Ce 3+ garnet phosphor shows an intense absorption band in the 300–500 nm wavelength range with a maximum at 452 nm owing to the 4f→5d transition of Ce 3+ ions. On 452 nm excitation, the optimal CaGd 2 HfScAl 3 O 12 :2%Ce 3+ sample exhibits a broad asymmetric yellow emission band in the wavelength range of 470–750 nm with peak at 564 nm and full width at half maximum of 151 nm. The Commission Internationale de l’Eclairage chromaticity coordinates and internal quantum efficiency of the CaGd 2 HfScAl 3 O 12 :2%Ce 3+ sample are (0.4485, 0.5157) and 30.4%, respectively. Finally, a white LED device is fabricated by combing a 450 nm blue LED chip with commercial Y 3 Al 5 O 12 :Ce 3+ yellow-emitting phosphor, which generates white light with low color rendering index (CRI; Ra = 74.7, R9 = −12.7) and high correlated color temperature (CCT = 6,554 K) under the 60 mA driving current. In sharp contrast, another white LED device, which is made by coating our as-prepared CaGd 2 HfScAl 3 O 12 :2%Ce 3+ yellow-emitting phosphors onto the surface of a 450 nm blue LED chip, produces white-light emission with high CRI value (Ra = 84.5, R9 = 26.3) and relatively low CCT of 5,649 K. This work reveals that the newly discovered broadband yellow-emitting CaGd 2 HfScAl 3 O 12 :Ce 3+ phosphors can serve as a potential color converter in high-color-quality phosphor-converted white LEDs.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2022
·
IF 4.889
Wuyuan Liu,Zihan Gao,Ming Sun,Jiajian Gao,Lifeng Wang,Xiangyun Zhao,Runnong Yang,Lin Yu
A series of Cr α Mn β CeTiO x catalysts were prepared using one-pot precipitation method and evaluated for the selective catalytic reduction (SCR) of NO with ammonia. Among the catalysts prepared, the Cr 0.006 Mn 0.05 CeTiO x catalyst exhibited the highest low-temperature activity and widest activity window (＞90% NO conversion at 160–425 °C) as well as outstanding sulfur resistance. The catalysts were characterized using XRD, NH 3 /NO/SO 2 + O 2 -TPD, XPS, in situ DRIFT, and so on. The amorphous Cr 0.006 Mn 0.05 CeTiO x catalyst had a larger specific surface area, high ammonia adsorption and strong acidity, resulting in an improved catalytic activity. A high ratio of surface adsorption oxygen and Ce 3+ promoted the formation of NO 2 , a key intermediate gas in the fast SCR reaction. Furthermore, in situ DRIFT showed that the SCR reaction followed the Eley Rideal and Langmuir Hinshelwood mechanisms. Moreover, the synergetic effect of Cr and Mn inhibited the accumulation of hydrogen sulfate or sulfate considerably.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Physics
·
2023
·
IF 11.5
Jingming Chan,Lina Cao,Zhe Xu,Xiaoyong Huang
Highly efficient cyan-green-emitting phosphors are urgently needed for high-color-quality full-visible-spectrum white light-emitting diodes (LEDs). Herein, we report on efficient near-ultraviolet-excited cyan-green-emitting Ca 2 La 1- x Lu x Hf 2 Al 3 O 12 :Ce 3+ (CLa 1- x Lu x HA:Ce 3+ ) garnet phosphors, which are developed based on the solid-solution design of chemical cation substitution. All phosphor samples present a garnet crystal structure with the I a 3 ‾ d space group; with increasing Lu 3+ ions content, the lattice could be gradually contracted, along with a high symmetry as well as rigidity. Furthermore, under the 408 nm excitation, the cyan-green emissions of CLa 1- x Lu x HA:Ce 3+ phosphors are progressively enhanced with a slight blue-shift, due to crystal field splitting and Stokes shift . Importantly, quantum efficiency and thermal stability performances are greatly improved by introducing smaller Lu 3+ ions to replace the bigger La 3+ ions, owing to the high rigidity structure with high symmetry. The optimized CLa 0.5 Lu 0.5 HA:Ce 3+ phosphor exhibits an intense cyan-green emission band with high internal quantum efficiency of 76.4% and external quantum efficiency of 54.4%. Through employing the as-prepared CLa 0.5 Lu 0.5 HA:Ce 3+ cyan-green phosphor, we have successfully fabricated a full-visible-spectrum LED device, demonstrating a bright warm-white light emission with an extremely high color rendering index (Ra = 98.0, R9 = 95.9, and R12 = 94.3) and low correlated color temperature (3497 K) under 100 mA driving current. This study not only reveals the correlation between the crystal structure evolution and luminescent properties of phosphor materials, but also provides new strategies for the design and development of novel efficient luminescent materials for high-quality full-visible-spectrum LED lighting.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Chuandong Chen,Shuaijun Yue,Yang Liu,Hongpeng You
The precision polishing process plays a crucial role in the modern advanced semiconductor manufacturing field, making it imperative to develop excellent polishing abrasives through new techniques. In this study, we obtained well-defined spherical nano-composite polishing particles CeO 2 @SiO 2 via posterior grafting synthesis, which have a clear core–shell structure and exhibit a high Ce 3+ concentration. Atomic force microscopy revealed significant improvement in surface roughness of the abrasives on Si substrates, achieving the material removal rate (MRR) of 300 nm/min. MRR is closely correlated with the Ce 3+ concentration. Combining aberration-corrected transmission electron microscopy with first-principles calculations demonstrated that surface oxygen vacancies and interfacial charge transfer were the primary origins of high Ce 3+ concentration, and revealed the material removal mechanism. This work not only provides new insights into the process but also offers new routes for the development of novel polishing abrasives in the future.
研究领域:
材料科学
·
半导体制造
✓ 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）