scholarly journals Visible Light Photocatalysis with Rare Earth Ion-Doped Nanocomposites

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Himanshu Narayan ◽  
Hailemichael Alemu ◽  
Lijeloang Setofolo ◽  
Lebohang Macheli
Keyword(s):  
Particle Size ◽  
Rare Earth ◽  
Visible Light ◽  
Apparent Rate Constant ◽  
Rare Earth Ions ◽  
Rare Earth Ion ◽  
Effective Suppression ◽  
Co Precipitation ◽  
Average Size ◽  
Visible Light Photocatalytic

Rare earth (R) ion-doped TiO2 nanocomposites (NCs) with general composition (R: Y, Yb, Gd; , 0.2) were synthesized through co-precipitation/hydrolysis (CPH). NC particles with average size of approximately a few tens of nm were obtained. Similar compositions of polycrystalline (PC) samples with larger particle size were also prepared employing solid state reaction (SSR) method. Visible light photocatalytic activity of all samples was investigated for degradation of Congo red (CR) dye. Both in terms of apparent rate constant () and percent degradation after 180 min (), all NCs produced significantly enhanced degradation as compared to pure TiO2 and PC samples. Best degradation of 95% ( value) resulted with composition of Y3+ doped NC with  min−1. This was followed by of 85 and 80%, produced with Yb3+ and Gd3+ doped, NCs, at around and  min−1, respectively. The observations clearly suggest that enhanced photocatalytic degradation of CR is directly related to smaller particle size of the catalysts. Moreover, the presence of rare earth ions in the composites facilitates further improvement of degradation efficiency through effective suppression of recombination.

scholarly journals Structure, Luminescence, and Magnetic Properties of Crystalline Manganese Tungstate Doped with Rare Earth Ion

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3717
Author(s):  
Jae-Young Jung ◽  
Soung-Soo Yi ◽  
Dong-Hyun Hwang ◽  
Chang-Sik Son
Keyword(s):  
Magnetic Field ◽  
Rare Earth ◽  
Sintering Temperature ◽  
Luminescent Properties ◽  
Concentration Quenching ◽  
Rare Earth Ions ◽  
Precipitation Method ◽  
Rare Earth Ion ◽  
Co Precipitation ◽  
Quenching Phenomenon

The precursor prepared by co-precipitation method was sintered at various temperatures to synthesize crystalline manganese tungstate (MnWO4). Sintered MnWO4 showed the best crystallinity at a sintering temperature of 800 °C. Rare earth ion (Dysprosium; Dy3+) was added when preparing the precursor to enhance the magnetic and luminescent properties of crystalline MnWO4 based on these sintering temperature conditions. As the amount of rare earth ions was changed, the magnetic and luminescent characteristics were enhanced; however, after 0.1 mol.%, the luminescent characteristics decreased due to the concentration quenching phenomenon. In addition, a composite was prepared by mixing MnWO4 powder, with enhanced magnetism and luminescence properties due to the addition of dysprosium, with epoxy. To one of the two prepared composites a magnetic field was applied to induce alignment of the MnWO4 particles. Aligned particles showed stronger luminescence than the composite sample prepared with unsorted particles. As a result of this, it was suggested that it can be used as phosphor and a photosensitizer by utilizing the magnetic and luminescent properties of the synthesized MnWO4 powder with the addition of rare earth ions.

Visible-light excited polar Dion-Jacobson Rb(Bi1-xEux)2Ti2NbO10 perovskite: Photoluminescence properties and in-vitro bioimaging

2022 ◽  
Author(s):  
Debendra Prasad Panda ◽  
Akash Kumar Singh ◽  
Tapas Kumar Kundu ◽  
Sundaresan Athinarayanan
Keyword(s):  
Quantum Dots ◽  
Rare Earth ◽  
Visible Light ◽  
Organic Dyes ◽  
Photoluminescence Properties ◽  
Rare Earth Ion

Rare-earth ion-activated oxide phosphors are beneficial to overcome the problems like photobleaching, reduced lifetime, and the blinking of organic dyes and quantum dots for bioimaging applications. In this work, we...

The magnetic and spectroscopic properties of certain rare-earth double nitrates

1955 ◽  
Vol 232 (1191) ◽  
pp. 458-474 ◽  
Keyword(s):  
Rare Earth ◽  
Electric Field ◽  
Spectroscopic Properties ◽  
Rare Earth Ions ◽  
Rare Earth Ion ◽  
Crystalline Electric Field ◽  
Paramagnetic Resonance ◽  
Systematic Fashion ◽  
Resonance Data ◽  
Rare Earth Series

The theory that has been developed for rare-earth ions in crystals is here applied to the double nitrates. The paramagnetic resonance data and certain spectroscopic properties of the different rare-earth double nitrates, depending as they do on the crystalline electric field at a rare-earth ion, are related to the six parameters through which the field is defined. It is found that most of the experimental results can be fitted to values of the parameters that vary in a systematic fashion along the rare-earth series.

Synthesis, Morphology Control and Luminescent Properties of Rare Earth Ion-Doped CaWO4 Microstructures

2016 ◽  
Vol 16 (4) ◽  
pp. 4029-4034 ◽  
Author(s):  
Chunxia Liu ◽  
Lixia Yang ◽  
Dan Yue ◽  
Mengnan Wang ◽  
Lin Jin ◽  
...  
Keyword(s):  
Rare Earth ◽  
Uv Light ◽  
Luminescent Properties ◽  
Average Diameter ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Rare Earth Ion ◽  
X Ray ◽  
Facile Hydrothermal Route

Rare earth ions (Tb3+, Eu3+) doped CaWO4 microstructures were synthesized by a facile hydrothermal route without using any templates and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectrum. The results indicate that the asprepared samples are well crystallized with scheelite structure of CaWO4, and the average diameter of the microstructures is 2∼4 μm. The morphology of CaWO4:Eu3+ microstructures can be controllably changed from microspheres to microflowers through altering the doping concentration of Eu3+ from 3% to 35%, and the microflowers are constructed by a number of CaWO4:Eu3+ nanoflakes. Under the excitation of UV light, the emission spectrum of CaWO4:Eu3+ is composed of the characteristics emission of Eu3+ 5D0-7FJ (J = 1, 2, 3, 4) transitions, and that of CaWO4:Tb3+ is composed of Tb3+ 5D4-7FJ (J = 6, 5, 4, 3) transitions. Both of the optimal doping concentrations of Tb3+ and Eu3+ in CaWO4 microstructures are about 5%.

Optical temperature sensing of rare-earth ion doped phosphors

RSC Advances ◽  
2015 ◽  
Vol 5 (105) ◽  
pp. 86219-86236 ◽  
Author(s):  
Xiangfu Wang ◽  
Qing Liu ◽  
Yanyan Bu ◽  
Chun-Sheng Liu ◽  
Tao Liu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Temperature Measurement ◽  
Large Scale ◽  
Temperature Sensing ◽  
Rare Earth Ions ◽  
Promising Method ◽  
Current Status ◽  
Rare Earth Ion ◽  
Optical Thermometry

Optical temperature sensing is a promising method to achieve the contactless temperature measurement and large-scale imaging. The current status of optical thermometry of rare-earth ions doped phosphors is reviewed in detail.

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