OPTICS AND LASER TECHNOLOGY
·
2017
·
IF 2.109
Jiangyun Dai,Guoying Feng,Shutong Wang,Hong Zhang,Shengyu Dai,Shouhuan Zhou
By using femtosecond-pulsed laser to ablate the larger nanosized target in liquid, stable transparent NaGdF 4 :Nd 3+ colloid has been successfully fabricated. The X-ray diffraction (XRD) spectra reveal that the colloidal nanoparticles remain the hexagonal phase crystal structure of NaGdF 4 powder target. SEM and TEM images results indicate that the size of these colloidal nanoparticles decreases sharply. FT-IR results indicate that the number of O–H and C–H groups on the surface is decreased. The emission properties of the colloid have been investigated using 794 nm pulsed wave laser radiation , and it is found that the colloid exhibits near-infrared luminescent emissions in the spectral range of 850–1400 nm, and the decay time for 4 F 3/2 → 4 I 11/2 (1058 nm) Nd 3+ ion transitions is lengthened than that of powder target, these results are probably due to the reduced nonradiative relaxation assisted by high energy oscillators . The observed near-infrared emission of the stable transparent colloid makes it a good candidate for application in liquid laser .
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2022
·
IF 5.723
Yitong Lin,Taiyu Jin,Yu Liu,Jianhe Tang,Ying Tian,Xueke Liu,Liang Chen,Dawei Fang,Jun Wang
A coated Z-scheme NaGdF 4 :Nd 3+ ,Yb 3+ ,Tm 3+ @CdS-Pd@NiO photocatalyst with core-shell structure is prepared by hydrothermal and coprecipitation methods. NaGdF 4 :Nd 3+ ,Yb 3+ ,Tm 3+ as excellent up-conversion luminescent material can convert infrared light into visible light, broadening the light response range of CdS. Pd nanorods act as conductive channels and co-catalysts, leading to successful construction of titled photocatalyst, increasing contact area between two monomer photocatalysts, promoting transfer of photo-generated electrons. It also provides a large oxidation surface for organic pollutant degradation. The performance of prepared photocatalyst is assessed by Congo red degradation and hydrogen production . The emission spectrum and energy conversion mechanism of NaGdF 4 :Nd 3+ ,Yb 3+ ,Tm 3+ are investigated. The photocatalyst with 3:1 NaGdF 4 :Nd 3+ ,Yb 3+ ,Tm 3+ @CdS-Pd and NiO mass ratio has a preeminent activity. Congo red degradation ratio and hydrogen production amount reach 92.48% and 653.06 µmol/g, respectively, under simulated sunlight irradiation for 180 min. The possible mechanism of organic pollutant degradation with synchronous hydrogen production caused by titled photocatalyst is proposed.
研究领域:
材料科学
·
环境科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 13
·5109-5115
·
IF 8.067
Tao Pang,Yanyan Wu,Yujian Zhang,Ronghua Jian,Junwen Mao,Hong Wang,Hai Guo
Although much effort has been focused on thermally enhanced upconversion (UC) luminescence, it remains a challenge to maintain or even enhance the UC luminescence of NaLnF4-based phosphors (Ln = Y, Gd, Lu) using a surface-independent strategy. In this work, we demonstrate that the effect of temperature on UC luminescence in NaGdF4:Nd3+/Yb3+/Er3+ nanocrystals is strongly dependent on the exciting wavelength. When excited using 808 nm radiation, the UC luminescence exhibits good resistance to thermal quenching. The reason is that, in this situation, the negative effect of multi-phonon decay can be fully compensated by the thermal enhancement in the transition cross-section and in energy-transfer rate. Our research reports a novel strategy for the anti-thermal quenching of upconversion luminescence, which is potentially applicable in the design of dynamic UC anti-counterfeiting as well as in NIR-I-responsive thermometers and nanoheating.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 31
·18070-18075
·
IF 3.049
Yabing Li,Fujin Li,Yanan Huang,Haiyan Wu,Jian Wang,Jin Yang,Qingbo Xiao,Hongzhen Lin
Small-sized lanthanide-doped nanoparticles (NPs) exhibiting superior near-infrared (NIR) luminescence properties are highly desired for bioimaging applications. Herein, Fe3+ ions are codoped in NaGdF4:Nd3+ nanocrystals via a simple coprecipitation method, which can simultaneously reduce the particle size and enhance the downconverting NIR luminescence of the NPs. The NIR luminescence intensity reaches the maximum for the obtained sub-5 nm NPs when the doping concentration of Fe3+ is tuned to 20 mol%, which is ∼1.7 times higher than that of the pristine 8.7 nm NPs without Fe3+ doping. After being modified with targeting molecules, the ultra-small NaGdF4:Nd3+,Fe3+ NPs were successfully applied as luminescent probes for targeted NIR imaging of tumors in biological tissues. Moreover, they also show great potential as a high contrast agent for T2-weighted MRI imaging.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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