ACS Applied Nano Materials
·
2021
·
IF 5.097
Yuxian Su,Li Liu,Shipeng Wen
Semiconductor photocatalysis is a promising strategy for wastewater treatment. However, a limited photoresponse range, rapid recombination of photoinduced charge carriers, poor stability, and other problems have posed obstacles to practical applications. Herein, a facile strategy to fabricate a near-infrared-driven broadband photocatalyst was developed by anchoring the core–shell nanostructure of NaYF4:Yb,Tm@NaYF4:Yb,Nd@TiO2 (Tm@Nd@TiO2) onto the surface of porous silica/carbon (mSC) electrospun fibers. The Tm@Nd@TiO2 nanoparticles (NPs) exhibited strong near-infrared light absorption and energy transfer from the NaYF4:Yb,Tm@NaYF4:Yb,Nd core to the TiO2 shell, triggering the photocatalytic reaction. In addition, the interconnected mesoporous structure and carbon network of Tm@Nd@TiO2/mSC was found to be beneficial in improving the adsorption capacity toward organic pollutants, promoting the separation of photogenerated carriers, and further improving the overall photocatalytic performance. The photocatalytic activity of Tm@Nd@TiO2/mSC nanocomposite was evaluated by degrading methyl orange solution in the visible-near-infrared and simulated sunlight regions. The Tm@Nd@TiO2/mSC nanocomposite exhibited excellent adsorption performance. The photocatalytic activity of Tm@Nd@TiO2/mSC was found to be 3 times higher than that of bare Tm@Nd@TiO2 over 60 min.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Dangli Gao,Yuqian Liang,Jie Gao,Hong Xin,Long Wang,Sining Yun,Xiangyu Zhang
Applications of rare-earth (Re)-doped upconversion (UC) micro/nanocrystals in varying areas have sparked a growing, constant demand for deliberate control over the luminescent profile and lifetime. A general strategy for adjusting UC luminescence is to control the dopant Re 3+ concentration. However, the progress of elevating dopant concentration is significantly limited owing to frequently encountering severe concentration quenching. Herein, by designing UC system using Tm 3+ with super long intermediate energy level lifetime and Yb 3+ with a simple two-level structure as a activator/sensitizer combination, we have achieved the unusually intense deep ultraviolet (UV) UC emissions at 290 nm and 345 nm, near UV emission at 361 nm, visible blue emissions at 452 nm and 478 nm, and near infrared (NIR) emission at 803 nm in NaYF 4 :Yb/Tm microtubes under 980 nm excitation. The luminescence intensity reaches about 56 times and 8 times enhancement for the UV and blue emission, respectively, with the increase of dopant Yb 3+ contents from 20 to 80 mol%. While luminescence lifetimes for all emissions decrease, particularly, for NIR emission at 803 nm, from 1507 μs down to 384 μs. Importantly, upon 980 nm irradiation, these UC NaYF 4 :Yb/Tm microtubes exhibit superior optical performance as a promising candidate of advanced anti-counterfeiting applications and other applications including UV light triggered reactions and multiplexing information storage.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2023
·
IF 3.1
Aihua Zhou,Jiaxin Yang,Yan Li,Chengguo Ming,Yuanxue Cai,Yumiao Pei
Luminescence thermometry has recently been gaining popularity in science and technology fields. However, most reported works have used the fluorescence intensity ratio (FIR) to obtain the temperature based on thermally coupled energy levels (TCLs), which have hindered the sensitivity of the technique and limited its applications. Here, NaYF4:Yb/Tm@NaYF4:Yb/Ho microcrystals were prepared using a hydrothermal method. Based on the non-thermally coupled energy levels (NTCLs) of the double luminescent ionic centers Tm3+ and Ho3+, the materials exhibited temperature-dependent luminescence in the range of 304 K to 574 K. The maximum sensitivities were found to be Sa = 0.135 K−1 at 574 K and Sr = 1.101% K−1 at 484 K based on red (Tm3+) and green (Ho3+) emission bands. This study has provided a promising new strategy to break the TCL restriction and has shown the material to have potential applications in luminescence thermometry.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2018
·
IF 3.972
Lihua He,Xiao Zou,Xiang He,Fengying Lei,Na Jiang,Qiaoji Zheng,Chenggang Xu,Yongfu Liu,Dunmin Lin
A variety of NaYF4:Yb/Er upconversion materials were successfully synthesized via a facile hydrothermal method by altering the volume ratios (0:1, 1:1, 2:1, 3:1, 4:1, 5:1) of ethanol to water and various alcohols (methanol, n-propyl alcohol, isopropyl alcohol, ethylene glycol, polyethylene glycol, and phemethylol), and the grain size and luminescence of the materials were effectively tailored. The addition of alcohol effectively reduces the grain size of the materials and simultaneously leads to the surprising enhancement of the UC emission. The increase in the volume ratio of EtOH/H2O causes the transformation of the crystal structure of the materials from hexagonal to cubic phase. The particle size of the material with the EtOH/H2O of 2:1 is almost 1000 times smaller than that of the material without EtOH, and the strongest luminescence is observed at the EtOH/H2O of 2:1. The type of alcohol in the solvent exhibits a significant influence on the luminescent properties of the materials. The NaYF4:Yb/Er nanocrystals obtained using different alcohols as solvent possess much a smaller grain size and stronger upconversion luminescence than that using water as solvent, and the NaYF4:Yb/Er materials with n-propyl alcohol exhibit the strongest luminescence intensity. The mechanism of the reduction of grain size and enhancement in the luminescence of the NaYF4:Yb3+, Er3+ upconversion materials has been proposed. This study may suggest a simple method to significantly reduce the grain size and improve the upconversion luminescence properties of NaYF4-based fluorescence material.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2021
·Vol. 101
·期 1
·215-226
·
IF 2.326
Li Ping,Zhao Liuyong,Wang Song,Zhang Xiaohui,Jiang Huaiyuan,Liu Ruizhen,Zhao Nengchuang,Cheng Jian,Xu Caili,Zhao He,Lyu Renliang
Known as one efficient upconversion luminescent material, Rare-earth ions doped natrium yttrium fluoride NaYF 4 :Yb/Re has broad application prospects. However, due to the limitation of the existing preparation methods, it is difficult to realize industrial production. In this paper, the upconversion luminescence microparticles, rare earth ions doped Natrium Yttrium Fluoride NaYF 4 :Yb/Er, were synthesized productively by impinging stream method. Synthesis conditions were optimized as EDTA: Ln to 0.5 and NaF: Ln to 6 (Ln represents the sum of moles of Y, Yb, and Er), reacting temperature and time to 50 °C and 3 h to obtain a high yield of 99.92% and particle with good monodispersity. To get strong upconversion luminescence, the effect of the calcination temperature and the amount of EDTA were investigated. The bright upconversion emissions by excited with laser radiation at 975 nm were found at 510–690 nm. The higher the calcination temperature, the stronger the luminescence and the strongest luminescence occurs when calcined at 600 °C. And the adding of EDTA will decrease the luminescence intensity. However, the sintering of particles at high temperatures and aggregation of particles without EDTA are unfavorable for the application of the products. Based on the above considerations, the optimal calcination temperature was determined at 450 °C, and the ratio of EDTA: Ln is preferred at 0.5. The impinging stream method to prepare upconversion material has the advantages of being simple in the process and equipment, high in output, low in investment, and convenient to be applied and popularized.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 61
·35306-35313
·
IF 2.936
Pengpeng Feng,Yusong Pan,Hui Ye
NaYF4:Yb,Tm upconversion nanocrystals with hexagonal structure possess excellent photoluminescence emission characteristics. Under near infrared (NIR) light irradiation, the Yb3+ ions act as sensitizers to absorb the NIR light and transform NIR light into ultraviolet (UV) and visible (Vis) light continuously. Hybrid NIR-activated photocatalysts can be fabricated by combining upconversion nanocrystals with various semiconductor nanocrystals. In this paper, NaYF4:Yb,Tm micro-rods were hydrothermally synthesized with oleic acid as capping ligand. The NaYF4:Yb,Tm@CdS composite was fabricated by in situ generation of CdS nanoclusters on the surface of NaYF4:Yb,Tm micro-rods. The morphologies and structures of NaY4:Yb,Tm and NaYF4:Yb,Tm@CdS were characterized by XRD, SEM, TEM, XPS, UV-Vis and PL spectroscopy. The results of photocatalytic experiments indicated that the NaYF4:Yb,Tm@CdS composite displayed photocatalytic activity under NIR irradiation. In comparison with pure CdS, the photocatalytic ability of NaYF4:Yb,Tm@CdS composite under Vis-NIR irradiation was obviously enhanced. 82% of RhB was degraded by NaYF4:Yb,Tm@CdS catalyst within 75 min under Vis-NIR irradiation, which was more effective than pure CdS (65% degradation of RhB).
研究领域:
材料科学
·
纳米技术
·
光催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2018
·Vol. 8
·期 12
·1023
·
IF 3.504
Dandan Ju,Feng Song,Adnan Khan,Feifei Song,Aihua Zhou,Xiaoli Gao,Huimin Hu,Xu Sang,Victor Zadkov
The dual-mode emission and multicolor outputs in the time domain from core-shell microcrystals are presented. The core-shell microcrystals, with NaYF4:Yb/Er as the core and NaYF4:Ce/Tb/Eu as the shell, were successfully fabricated by employing the hydrothermal method, which confines the activator ions into a separate region and minimizes the effect of surface quenching. The material is capable of both upconversion and downshifting emission, and their multicolor outputs in response to 980 nm near-infrared (NIR) excitation laser and 252 nm, and 395 nm ultraviolet (UV) excitation light have been investigated. Furthermore, the tunable color emissions by controlling the Tb3+-Eu3+ratio in shells and the energy transfer of Ce3+→Tb3+→Eu3+were discussed in details. In addition, color tuning of core-shell-structured microrods from green to red region in the time domain could be obtained by setting suitable delay time. Due to downshifting multicolor outputs (time-resolved and pump-wavelength-induced downshifting) coupled with the upconversion mode, the core-shell microrods can be potentially applied to displays and high-level security.Keywords:NaYF4:Yb/Er@NaYF4:Ce/Tb/Eu microrods;dual-mode emission;time-resolved emission spectra;multicolor emission
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
Suli Wu,Yanhui Ning,Jie Chang,Shufen Zhang
Here, hydro/solvent thermal method was applied to synthesize lanthanide doped NaYF 4 upconversion nanoparticles (UCNPs). In order to overcome the quenching effect of (CH 2 ) n due to their high energy stretching vibration , a series of new chelating ligands such as, butanoic acid , hexanoic acid , decanoic acid , and tetradecanoic acid were selected for hydrothermal synthesis of NaYF 4 :Yb, Er nanocrystals . For comparison, commonly used oleic acid was also used as ligand for hydrothermal synthesis of UCNPs. The effect of the carbon chain length of chelating ligands on the NaYF 4 nanocrystals’ emission intensity was systematically investigated. It was found that relative short length of the carbon chain in chelating ligands resulted in enhancement of luminescent intensity and modulation of the ratios of green to red (RGR) of NaYF 4 :Yb, Er nanocrystals. In contrast to the product prepared with oleic acid as ligand, the enhancement factors of 540 nm emissions were 25, 21, 6.5, and 3 for samples prepared with butanoic acid, hexanoic acid, decanoic acid, and tetradecanoic acid as ligands, respectively. The FT-IR spectra of NaYF 4 :Yb, Er UCNPs prepared with different ligands indicated that ligands with relatively short chain length indeed have weak IR absorption in 2800–2950 cm −1 , which resulted in weak quenching effect of Er 3+ . We also synthesized NaYF 4 :Yb, Tm UCNPs with these ligands. The results showed that chain length of ligands has similar effect on emission intensity of NaYF 4 :Yb, Tm. It is expected that this method can also be applied to enhance the luminescence intensity of other luminescent materials.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Science of Advanced Materials
·
2017
·Vol. 9
·期 12
·2223-2233
·
IF 1.671
Tan Haihu,Xie Shaowen,Xu Jianxiong,Li Na,Zhang Changfang,Xu Lijian,Zheng Jie
Rational design and fabrication of multimodal imaging nanoprobes are of great significance for many imaging applications. Here, we report the systhesis of water-soluble hexagonal NaYF4:Yb, Er up-conversion phosphors (UCPs) with branched structure by hexadecylpyridinium chloride
(CPC) and tri-sodium citrate (Na3Cit) binary cationic/anionic capping agents assisted hydrothermal reaction. The crystal phase, morphology, and size of NaYF4:Yb, Er UCP were controlled by the concentration of Na3Cit and CPC, molar ratio of NaF:RE3+,
hydrothermal temperature, hydrothermal time, as well as analyzed by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), X-ray diffraction (XRD). By tuning and optimizing hydrothermal conditions, NaYF4 UCPs experienced the phase transition from pure cubic phase to
mixed cubic/hexagonal phases to pure hexagonal phase, as well as morphology changes from spherical nanoparticles to short pillar structures, and ultimately to branched structures. Due to the special geometrical shape, the branched NaYF4:Yb, Er UCPs could be blended with host materials
without further surface modification. As a proof-of-concept, branched NaYF4:Yb, Er phosphors were then incorporated into polyvinyl alcohol (PVA) matrix to develop a novel luminescence composite film. The resulting PVA/NaYF4:Yb, Er composite film possessed optical transparence
at daylight and emitted green fluorescence at the irradiation of a 980 nm laser. NaYF4:Yb, Er phosphors and hybrid PVA/NaYF4:Yb, Er demonstrate high potential of fluorescent materials used for anti-counterfeiting and other optical applications.
研究领域:
材料科学
·
纳米技术
·
光学材料
·
发光学
·
防伪技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 28
·14642-14650
·
IF 7.443
Yongmei Ma,Honglin Liu,Zhenzhen Han,Liangbao Yang,Jinhuai Liu
An effective near-infrared (NIR) active photocatalyst, NaYF4:Yb,Tm@TiO2/Ag (UC@TiO2/Ag) core@comby shell composite, was synthesized by a simple three-step hydrothermal process. Under the full-spectrum light of a Xe lamp in UV-Vis absorbance experiments, about 96% of R6G dyes in solution were degraded by UC@TiO2/Ag in 120 minutes, while only about 64% of the dyes were degraded by pure TiO2 under the same conditions. Under a UV-filtered Xe lamp, about 35% of the dyes were degraded by UC@TiO2/Ag in 120 minutes; interestingly, only about 8% of the dyes were degraded by pure TiO2. Under irradiation by a 785 nm laser in surface enhanced Raman scattering (SERS) experiments, the photodegradation rate constants were 0.02612 s−1 for UC@TiO2/Ag and 0.00046 s−1 for TiO2/Ag, indicating a nearly 58 fold improvement. After deducting the photobleaching effect, the photodegradation rate constants for UC@TiO2/Ag under 633 and 532 nm lasers were 0.00715 s−1 and 0.00565 s−1, respectively, revealing a sharp decrease under irradiation at shorter wavelengths. Electron spin resonance (ESR) analysis revealed that the presence of UC in this photocatalytic system certainly induced the increase of ˙OH free radicals with NIR irradiation, i.e. the UC core converts NIR light into ultraviolet (UV) light and initiates excellent photocatalytic activity of the TiO2/Ag comby shell. Furthermore, the decorating of Ag nanoparticles not only enhances the photocatalytic ability, but also provides a structural basis for monitoring the photocatalytic kinetics by the SERS technique. By virtue of monochrome laser lines, SERS analysis provides direct evidence to prove the capability of UC-initiated non-UV photocatalysis and the improvement of the utilization of non-UV lights on TiO2. The results revealed that this new photocatalytic platform can efficiently utilize different bands of the solar spectrum and also find new applications in SERS fields.
研究领域:
材料科学
·
光催化
·
纳米技术
·
光谱学
·
环境化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Chuanying Wang,Xianhua Cheng
In this work, β-NaYF 4 :Yb,Er upconversion (UC) film was successfully prepared on silicon (Si) substrate via self-assemble method for the first time. The chemical composition and surface morphology of the UC film were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), water contact angle (WCA), X-ray power diffraction (XRD), and scanning electron microscopy (SEM) measurements. To investigate the effects of KH-560 primer film and chemical reactions on the UC luminescence properties of β-NaYF 4 :Yb,Er UC film, decay profiles of the 540 nm and 655 nm radiations were measured. Furthermore, tribological test was applied to qualitatively evaluate the adhesion of the UC film. The results indicate that the UC film has been successfully prepared on Si substrate by covalent chemical bonds. This work provides a facile way to synthesize β-NaYF 4 :Yb,Er UC film with robust adhesion to the substrate, which can be applicable for other UC films.
研究领域:
材料科学
·
光学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Barbara Ting Wei Ang,Yin Mei Fong,Chew Beng Soh,Szu-Cheng Chien,Hui An,Ryan Hong Soon Tay
Tropical urban greenhouses are prone to heat trapping due to higher daily temperatures compared to temperate climates, and a high energy cost is required to maintain optimal growth conditions. Lanthanide-based nanoparticles are known for their capability of performing upconversion, a process where lower energy photons are absorbed and converted to a single photon of higher energy. These upconversion nanoparticles (UCNPs) possess the innate ability to convert infrared energy to visible light, thereby facilitating efficient heat removal while simultaneously providing upconverted visible light. Consequently, the incorporation of such material into greenhouse façades presents an attractive zero-energy alternative to commonly used greenhouse cooling technologies. In this study, NaYF4:Yb3+/Er3+ UCNPs were synthesized and coated onto a simulated greenhouse enclosure with Pak Choi plants to observe the effect of such a film coating on actual crop growth. A reduction of the interior temperature, increased sunlight diffusion, and improved crop yield were demonstrated in this work, showing promising results for future urban greenhouse façade applications.
研究领域:
农业科学
·
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）