Rare earth doped metal oxide nanoparticles for photocatalysis: a perspective

2021 ◽  
Author(s):  
Amir Mehtab ◽  
Jahangeer Ahmed ◽  
Saad M Alshehri ◽  
Yuanbing Mao ◽  
Tokeer Ahmad
Keyword(s):  
Rare Earth ◽  
Metal Oxides ◽  
Metal Oxide Nanoparticles ◽  
Rare Earth Metals ◽  
Visible Region ◽  
Rare Earth Doping ◽  
Electromagnetic Spectrum ◽  
As Doping ◽  
Carrier Recombination ◽  
Rare Earth Doped

Abstract Metal oxides are well-known materials that have been considered as the prominent photocatalysts. Photocatalysis is a promising way to address the environmental issues which arecaused by fossil fuel the combustion and industrial pollutants. Lots of efforts such as doping metal oxides with metals, non-metals or metals/non-metals have been made to enhance their photocatalytic activity. More specifically, in this review we have discussed detailed synthesis procedures of rare earth doped metal oxides performed in the past decades. The advantage of doping metal oxides with rare earth metals is that they readily combine with functional groups due to the 4f vacant orbitals. Moreover, doping rare earth metals causes absorbance shift to the visible region of the electromagnetic spectrum which results to show prominent photocatalysis in this region. The effect of rare earth doping on different parameters of metal oxides such as band gap and charge carrier recombination rate has been made in great details. In perspective section, we have given a brief description about how researchers can improve the photocatalytic efficiencies of different metal oxides in coming future. The strategies and outcomes outlined in this review are expected to stimulate the search for a whole new set of rare earth doped metal oxides for efficient photocatalytic applications.

scholarly journals Effect of Rare-Earth Doping on the Structural and Optical Properties of the Ag3AsS3 Crystals

2021 ◽  
Author(s):  
O.V. Smitiukh ◽  
O.V. Marchuk ◽  
Y.M. Kogut ◽  
V.O. Yukhymchuk ◽  
N.V. Mazur ◽  
...  
Keyword(s):  
Optical Properties ◽  
Rare Earth ◽  
Second Harmonic ◽  
Rare Earth Doping ◽  
Electromagnetic Spectrum ◽  
Non Linear ◽  
Nlo Materials ◽  
Linear Optical ◽  
Rare Earth Doped ◽  
The Rare Earth

Abstract Non-linear optical (NLO) materials allow the production of the coherent laser beam in the difficult frequency ranges of the electromagnetic spectrum. Aiming to explore new classes of the NLO materials with high optical performance in the infrared (IR) region, in this work, we investigated the effect of the rare earth doping (Pr, Eu, Yb) on the crystal structure and optical properties of the Ag3AsS3 crystals. The performed analysis of the XRD patterns indicates that the rare earth elements are located in the Ag sites of the crystal lattice. As a result, the second harmonic generation (SHG) intensity, which determines the effectiveness of the NLO materials, increases with the increase of rare earth dopant content up to 1.0 %. Using the absorption analysis and Raman spectroscopy, we show that the increase in the SHG intensity can be related to the slight decrease of the bandgap, as well as with the increased electron-phonon interaction in rare-earth-doped Ag3AsS3 crystals. Considering the discovered enhancement of the SHG intensity, accompanied by the low melting temperature, this work offers rare-earth-doped Ag3AsS3 crystals as potential candidates for the non-linear optical applications for the infrared frequency range.

Overview: Modification of Cerium Oxide in Three-Way Catalysts

2014 ◽  
Vol 575 ◽  
pp. 97-102 ◽  
Author(s):  
M. Nazri Abu Shah ◽  
S. Hanim Md Nor ◽  
Kamariah Noor Ismail ◽  
Abdul Hadi
Keyword(s):  
Thermal Stability ◽  
Rare Earth ◽  
Metal Oxides ◽  
Cerium Oxide ◽  
Storage Capacity ◽  
Rare Earth Metals ◽  
Oxygen Storage Capacity ◽  
Oxygen Storage ◽  
Alkaline Metals ◽  
Three Way Catalyst

An overview of modification of cerium oxide, CeO2which is employed in the three-way catalyst (TWCs) is presented in this article. The modifications of cerium oxide, CeO2incorporated with the metal oxides for the improvement of thermal stability, microstructure and oxygen storage capacity (OSC) are discussed. In view of that, the types of metal oxide are grouped into transition metals, rare earth metals, and alkaline metals and the effect of each group into cerium oxide, CeO2are elaborated.

Rare-Earth-Doped Pt/Ba/Ce0.6Zr0.4O2-Al2O3for NOxStorage and Reduction: The Effect of Rare-Earth Doping on Efficiency and Stability

ChemCatChem ◽  
2013 ◽  
Vol 6 (1) ◽  
pp. 237-244 ◽  
Author(s):  
Xiuyun Wang ◽  
Zhilin Chen ◽  
Yuling Wang ◽  
Ruihu Wang
Keyword(s):  
Rare Earth ◽  
Rare Earth Doping ◽  
Rare Earth Doped

Investigation on Rare Earth Doped Nonlinear Optical Potassium Hydrogen Phthalate (KHP) Single Crystals

2012 ◽  
Vol 584 ◽  
pp. 56-59 ◽  
Author(s):  
S. Sudhahar ◽  
M. Krishna Kumar ◽  
R. Mohan Kumar
Keyword(s):  
Rare Earth ◽  
Single Crystals ◽  
Nonlinear Optical ◽  
Visible Region ◽  
Optical Transmittance ◽  
Spectral Studies ◽  
Potassium Hydrogen Phthalate ◽  
Hydrogen Phthalate ◽  
Potassium Hydrogen ◽  
Rare Earth Doped

Rare earth doped potassium hydrogen phthalate (KHP) single crystals have been grown by slow evaporation technique. Single and powder X-ray diffraction analysis confirms the structural and crystallinity of grown crystals. The functional groups of pure and doped KAP crystals have been identified by FTIR spectral studies. UV-Vis studies explore the optical transmittance of the grown crystals in the entire visible region. Nonlinear optical property of the pure and doped KHP crystals was confirmed by Kurtz-Perry powder test.

Structures and Optical Properties of Nanoforest-Like Carbon Nanotubes Decorated with Nanoparticles of Strontium Aluminate Doped with Rare-Earth Elements

MRS Advances ◽  
2018 ◽  
Vol 3 (1-2) ◽  
pp. 121-126
Author(s):  
Patsy Y. Arquieta Guillén ◽  
Alena Borisovna Kharissova ◽  
Beatriz Ortega García ◽  
Oxana V. Kharissova
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Metal Oxides ◽  
Spray Pyrolysis ◽  
Metal Oxide Nanoparticles ◽  
Strontium Aluminate ◽  
Fluorescent Properties ◽  
Multi Wall Carbon Nanotubes

ABSTRACTNowadays, carbon nanotubes have a lot of applications in daily life, being applied in the fabrication of cellphones, computers, nanotransistors, among many others. Currently, their new applications in biotechnology area are in research, in particular in order to find new biosensors with fluorescent properties applying on the basis of multi-wall carbon nanotubes (MWCNTs). In this work, the obtaining of carbon nanoparticles having fluorescent properties via spray pyrolysis is presented. Synthesis, properties, structural peculiarities, and applications of nanobuds and related nanostructures are discussed. MWCNTs, decorated with strontium aluminate SrAl12O19 and doped with rare-earth elements, were synthetized from distinct organic precursors and the corresponding metal oxides. The metal oxides used were Samarium (Sm), Europium (Eu), Neodymium (Nd), Lanthanum (La), Cerium (Ce) and some their combinations.The synthesis was carried out on the surface of optical fibres to obtain a uniform growth of forest-like MWCNTs, adding to metal oxide nanoparticles to their surface. The preparation of composites was carried out by spray pyrolysis techniques in dry nitrogen atmosphere in the temperature range from 780 to 850°C. The formed products were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), FTIR spectroscopy, Raman spectroscopy and UV/visible spectroscopies. The analysis of the obtained data shows that the deposited nanoparticles are in the range of size 20-60 nm being uniformly distributed on the surface of MWCNTs. The samples, obtained at different temperatures and with doping metal oxides added to SrAl12O19, show different fluorescence behavior. The best results were observed with lanthanum oxide as a dopant. Possible applications as persistently luminescent phosphors for the formed MWCNTs-supported luminescent materials are proposed.

Covering the optical spectrum through collective rare-earth doping of NaGdF4 nanoparticles: 806 and 980 nm excitation routes

2017 ◽  
Vol 19 (19) ◽  
pp. 11825-11834 ◽  
Author(s):  
A. Skripka ◽  
R. Marin ◽  
A. Benayas ◽  
P. Canton ◽  
E. Hemmer ◽  
...  
Keyword(s):  
Rare Earth ◽  
Optical Spectrum ◽  
Near Infrared ◽  
Rare Earth Doping ◽  
Rare Earth Doped

Sensitization of numerous emission bands (from ultraviolet to near-infrared) in rare-earth doped multilayered nanoparticles: 806 versus 980 nm excitation.

Inorganic pigments based on fluorite-type oxynitrides

2006 ◽  
Vol 21 (6) ◽  
pp. 1427-1433 ◽  
Author(s):  
M. Pérez-Estébanez ◽  
R. Pastrana-Fábregas ◽  
J. Isasi-Marín ◽  
R. Sáez-Puche
Keyword(s):  
Rare Earth ◽  
Fluorite Structure ◽  
Rare Earth Doping ◽  
Inorganic Pigments ◽  
Doping Amount ◽  
Cubic Symmetry ◽  
Fluorite Type ◽  
Cie Lab ◽  
Symmetry Space ◽  
Rare Earth Doped

Zirconia oxynitride rare-earth-doped pigments were prepared by ammonolysis of the zirconium rare-earth oxides, previously synthesized using the citrate complexation/calcination route. Different coloration has been obtained, the intensity of which is a function of the nitrogen amount in the case of the oxynitrides; in the case of the oxides, both color and intensity depend on the doping amount of rare earth. The obtained phases, Zr(1−x)CexO2, Zr(1−x)RxO(2−x/2)□x/2, with R = Eu or Er and Zr(1−x)RxO(2−x/2−3/2y)Ny□x/2■y/2 (R = Ce, Eu, and Er), have been characterized by x-ray powder diffraction, scanning electron microscopy, and reflectance spectra data. These results show that the phases with minor rare-earth concentration adopt a baddeleyite-type structure, with a monoclinic symmetry, space group P21/c. By increasing the rare-earth doping, the obtained phases crystallize with the fluorite structure with tetragonal (P42/nmc) or cubic symmetry (Fm¯3m). On the other hand, the study of the magnetic properties of the oxides and oxynitrides indicate a paramagnetic behavior, and in the case of the cerium oxide, the nitridation process produces the reduction from Ce4+ to Ce3+. Diffuse reflectance data and CIE-LAB color coordinates suggest that these ceramics based on nitrogen containing zirconia are expected to be promising candidates as new ecological inorganic pigments.

Facile nanoparticle dispersion detection in energetic composites by rare earth doped in metal oxide nanostructures

RSC Advances ◽  
2015 ◽  
Vol 5 (84) ◽  
pp. 68305-68313 ◽  
Author(s):  
Robert E. Draper ◽  
David L. Reid ◽  
Tamil S. Sakthivel ◽  
Thomas Sammet ◽  
Andrew Demko ◽  
...  
Keyword(s):  
Rare Earth ◽  
Metal Oxide ◽  
Polymer Matrix ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Nanoparticle Dispersion ◽  
Oxide Nanostructures ◽  
Metal Oxide Nanostructures ◽  
Energetic Composites ◽  
Rare Earth Doped

Visible-light method utilizing consumer grade digital photography to characterize the dispersion properties of metal-oxide nanoparticles in a polymer matrix.

Rare-Earth Doped Silicon-Rich Silica: Evidence for Energy Transfer between Silicon Microclusters and Rare-Earth Ions

1994 ◽  
Vol 358 ◽  
Author(s):  
A.J. Kenyon ◽  
P.F. Trwoga ◽  
M. Federighi ◽  
C.W. Pitt
Keyword(s):  
Rare Earth ◽  
Visible Region ◽  
Rare Earth Ions ◽  
Excitation Wavelength ◽  
Rare Earth Ion ◽  
Absorption Bands ◽  
Strong Luminescence ◽  
Doped Silicon ◽  
Rare Earth Doped ◽  
The Rare Earth

ABSTRACTWe report the fabrication of rare-earth doped silicon-rich silica thin films by PECVD. The films exhibit absorption edges in the visible region of the optical spectrum consistent with the presence of silicon microclusters. Weak visible photoluminescence due to silicon microclusters is observed. In addition, strong luminescence from the rare-earth ion is obtained even when excited away from characteristic absorption bands; indeed, the luminescence intensity is largely independent of excitation wavelength below 514 nm. We ascribe this to excitation of silicon microclusters followed by an efficient transfer of energy to the rare-earth ions.The very broad absorption of this material opens up the possibility for flashlamp-pumped optoelectronic devices. In addition, we report the fabrication of silicon-rich silica films by PECVD. We show that the optical properties of these films are consistent with the presence of silicon microclusters and show absorption spectra similar to those of the rare-earth doped silicon-rich silica samples. This supports the hypothesis that the principal absorbing species in the rare-earth doped films is microclustered silicon

Preparation and Properties of Rare Earth-Doped TiO2 Thin Films by Sol-Gel Process

2014 ◽  
Vol 1033-1034 ◽  
pp. 1235-1238
Author(s):  
Tao Bai ◽  
Shi Gen Zhu
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Sol Gel ◽  
Rare Earth Doping ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Scanning Electronmicroscopy ◽  
Rare Earth Doped ◽  
The Rare Earth

Rare earth doped titaniumdioxide (TiO2) thin films (rare earth-doped TiO2) have been successfully prepared on a glass substrate by a sol–gel route. After the rare earth-doped TiO2thin films were calcined at 773K for 1h, the effect of rare earth-doping on the properties were investigated using X-ray diffraction (XRD), scanning electronmicroscopy (SEM), ultraviolet–visible spectroscopy and thermogravimetric techniques (TG/DTG). The XRD results showed that rare earth-doped TiO2thin films contained only a single crystalline phase of anatase TiO2after calcining at 773K for 1h. SEM micrographs showed that rare earth-doped TiO2thin films have smooth surfaces containing granular nanocrystallines and are without cracks. The UV–vis absorption spectra showed that the absorption of the rare earth-doped TiO2thin films has a red-shift. From ambient to 1273K, it is about 12% of mass loss because of the volatilizing of water and organic and the phase transformation.

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