Enhanced red upconversion emission and its mechanism in Yb3+–Er3+ codoped α-NaLuF4 nanoparticles

Transparent glass-ceramic composites embedded with Ln-fluoride nanocrystals are prepared in this work to enhance the upconversion luminescence of Tm3+. The crystalline phases, microstructures, and photoluminescence properties of samples are carefully investigated. KYb3F10 nanocrystals are proved to controllably precipitate in the glass-ceramics via the inducing of Yb3+ when the doping concentration varies from 0.5 to 1.5 mol%. Pure near-infrared upconversion emissions are observed and the emission intensities are enhanced in the glass-ceramics as compared to in the precursor glass due to the incorporation of Tm3+ into the KYb3F10 crystal structures via substitutions for Yb3+. Furthermore, KYb2F7 crystals are also nano-crystallized in the glass-ceramics when the Yb3+ concentration exceeds 2.0 mol%. The upconversion emission intensity of Tm3+ is further enhanced by seven times as Tm3+ enters the lattice sites of pure KYb2F7 nanocrystals. The designed glass ceramics provide efficient gain materials for optical applications in the biological transmission window. Moreover, the controllable nano-crystallization strategy induced by Yb3+ opens a new way for engineering a wide range of functional nanomaterials with effective incorporation of Ln3+ ions into fluoride crystal structures.

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Tuning the size and upconversion emission of NaYF4:Yb3+/Pr3+ nanoparticles through Yb3+ doping

RSC Advances ◽

10.1039/c4ra11357h ◽

2014 ◽

Vol 4 (99) ◽

pp. 56302-56306 ◽

Cited By ~ 28

Author(s):

Shuwei Hao ◽

Wei Shao ◽

Hailong Qiu ◽

Yunfei Shang ◽

Rongwei Fan ◽

...

Keyword(s):

Upconversion Luminescence ◽

Upconversion Emission ◽

Simple Method

We introduce a simple method to tune the resulting size as well as the upconversion luminescence of NaYF4:Yb3+/Pr3+ nanoparticles through varying the sensitizer ytterbium concentration.

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MOLTEN SALT SYNTHESIS OF YF3:Yb3+/Ln3+(Ln = Er3+, Tm3+) MICROSHEETS WITH MULTICOLOR UPCONVERSION LUMINESCENCE

Functional Materials Letters ◽

10.1142/s1793604713500616 ◽

2013 ◽

Vol 06 (06) ◽

pp. 1350061 ◽

Cited By ~ 2

Author(s):

MINGYE DING ◽

CHUNHUA LU ◽

LINHAI CAO ◽

YARU NI ◽

ZHONGZI XU

Keyword(s):

Molten Salt ◽

Laser Diode ◽

Upconversion Luminescence ◽

Emission Spectra ◽

Upconversion Emission ◽

Molten Salt Synthesis ◽

Molten Salt Method ◽

Orthorhombic System ◽

Co Doping ◽

First Time

In this paper, highly crystalline YF 3: Yb 3+/ Ln 3+( Ln = Er 3+, Tm 3+) microsheets were successfully synthesized by a surfactant-free molten salt method for the first time. The results indicated that the as-obtained samples belonged to orthorhombic system and exhibited microsheets morphology with side lengths of 30 to 80 μm and wall thickness from 1 to 1.5 μm. By changing the dopant's species ( Ln 3+), multicolor (yellow and blue) upconversion emission can be observed in YF 3: Yb 3+/ Ln 3+ microsheets under 980 nm laser diode (LD) excitation. The upconversion mechanisms in co-doping YF 3 samples were analyzed in detail based on the emission spectra. Importantly, this approach not only proposes a new alternative in synthesizing such materials, but also opens the possibility to meet the increasing commercial demand.

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Model for Predicting the Initial Solution pH at Pre-Assumed Final pH and Concentration of Dissolved Zinc during Leaching of Galena in Butanoic Acid Solution

Journal of Minerals and Materials Characterization and Engineering ◽

10.4236/jmmce.2009.88054 ◽

2009 ◽

Vol 08 (08) ◽

pp. 621-633

Author(s):

C. I. Nwoye

Keyword(s):

Acid Solution ◽

Initial Solution ◽

Butanoic Acid ◽

Solution Ph

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Effects of organic acids and initial solution pH on photocatalytic degradation of bisphenol A (BPA) in a photo-Fenton-like process using goethite (α-FeOOH)

Photochemical & Photobiological Sciences ◽

10.1039/c6pp00051g ◽

2016 ◽

Vol 15 (8) ◽

pp. 1046-1053 ◽

Cited By ~ 22

Author(s):

Guangshan Zhang ◽

Qiao Wang ◽

Wen Zhang ◽

Tian Li ◽

Yixing Yuan ◽

...

Keyword(s):

Reaction Mechanism ◽

Bisphenol A ◽

Organic Acids ◽

Photocatalytic Degradation ◽

Initial Solution ◽

Solution Ph ◽

System P

Proposed reaction mechanism of BPA photodegradation in an α-FeOOH-oxalate synergistic system.

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Phase-Selective Hydrothermal Preparation and Upconversion Luminescence of NaYF4:Yb3+,Tm3+

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.690.120 ◽

2016 ◽

Vol 690 ◽

pp. 120-125 ◽

Cited By ~ 1

Author(s):

Thanataon Pornpatdetaudom ◽

Karn Serivalsatit

Keyword(s):

Reaction Time ◽

Near Infrared ◽

Hexagonal Phase ◽

Upconversion Luminescence ◽

Upconversion Emission ◽

High Energy ◽

Lanthanide Ions ◽

Cubic Phase ◽

Good Efficiency ◽

Hydrothermal Temperature

Upconversion luminescence materials have been proved to have a good efficiency on converting low energy light to high energy light. These materials have received considerable attentions for many applications such as bio-labels, sensors, using for developing solar cells and photocatalytic applications under sunlight. Among many inorganic host materials, NaYF4 has been proved to be the best for doping lanthanide ions and have a good upconversion emission due to its low phonon energy, chemical stability, and transparency in the near infrared to ultraviolet range. In this study, NaYF4:Yb3+,Tm3+ upconversion luminescence materials were synthesized by hydrothermal method at temperature of 90 to 200 °C for period between 1 to 24 hours. The synthesized NaYF4:Yb3+,Tm3+ were characterized by X-ray diffraction, scanning electron microscopy, and fluorescence spectroscopy. The hydrothermal temperature and reaction time have strongly influence on phases and upconversion emission of the synthesized NaYF4:Yb3+,Tm3+. At 90 °C for 1 hour of reaction time, the pure cubic phase of NaYF4:Yb3+,Tm3+ was found. After increasing temperature and reaction time, the NaYF4:Yb3+,Tm3+ converted from cubic phase to hexagonal phase. Under excitation of 980 nm diode laser, the hexagonal NaYF4:Yb3+,Tm3+ exhibited the emission wavelength at about 656 nm (3F2 → 3H6), 469, 492, 552 nm (1G4 → 3H6), 537 nm (1D2 → 3H5), 450, 461 nm (1D2 → 3F4), 362 nm (1D2 → 3H6) and 345 nm (1I6 → 3F4). The upconversion emission intensity of the hexagonal NaYF4:Yb3+,Tm3+ was much stronger, compared with that of the cubic NaYF4:Yb3+,Tm3+.

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Metal Adsorbent Prepared from Coir Pith as Agricultural Waste: Adsorption of Zn(II) and Pb(II) from Aqueous Solution

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.545.101 ◽

2013 ◽

Vol 545 ◽

pp. 101-108 ◽

Cited By ~ 1

Author(s):

Kitirote Wantala ◽

Nusavadee Pojananukij ◽

Pongsert Sriprom ◽

Tinnakorn Kumsaen ◽

Arthit Neramittagapong ◽

...

Keyword(s):

Aqueous Solution ◽

Adsorption Capacity ◽

Calcination Temperature ◽

Ph Value ◽

Agricultural Waste ◽

Initial Solution ◽

Order Kinetic ◽

Solution Ph ◽

Freundlich Isotherms ◽

Coir Pith

Adsorption of Zn(II) and Pb(II) from aqueous solution were studied by using modified coir pith as an adsorbent. The extended adsorption conditions were investigated as a function of calcination temperature, contact time, adsorbent size, initial pH of solution and initial Zn(II) and Pb(II) concentrations. The adsorption capacity increased rapidly in first 5 minute and reached equilibrium in 120 minutes for Zn(II) and 10 minutes for Pb(II). In case of Zn(II); the results showed that the calcination temperature of modified coir pith above 600oC gave the higher adsorption capacity. The sizes of modified coir pith have no effect on the adsorption capacity. The adsorption capacity increased with increasing initial solution pH value. In case of Pb(II); the calcination temperature of modified coir pith showed no effect on the adsorption capacity. The sizes of modified coir pith showed a little effect on the adsorption capacity. The adsorption capacity increased with increasing of initial solution pH value up to pH of 3 and then stable. The results also corresponded with the Langmuir and Freundlich isotherms and pseudo second order kinetic adsorption models. The modified coir pith gave a higher Zn(II) and Pb(II) adsorption capacity of 29.33 mg Zn(II)/g adsorbent and 36.50 mg Pb(II)/g adsorbent, respectively.

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Dependence of Stability of Sr5(AsO4)3OH on pH Value

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.692.229 ◽

2014 ◽

Vol 692 ◽

pp. 229-233

Author(s):

Yan Hua Huang ◽

Zong Ning Li ◽

Hui Qin ◽

Zong Qiang Zhu ◽

Yi Nian Zhu ◽

...

Keyword(s):

Solid Solution ◽

Ph Value ◽

Reaction System ◽

Initial Solution ◽

Alkaline Solutions ◽

Solution Ph ◽

Batch Dissolution ◽

Initial Ph

The object of this work was to determine the solubility and stability of the synthetic Sr5(AsO4)3OH solid solution at 25°C and the different initial pHs (pH at 2, 6 and 9) by batch dissolution experiments. The results indicated that with the initial pH value of 2, 6 and 9, the reaction system reached equilibrium after 2880h, and by that time the pH value of the solution reached, 7.90, 8.74 and 8.27 respectively. The concentration of strontium and arsenic in the initial solution pH at 2 are higher than that of solutions pH at 6 and 9. While the concentration of strontium in neutral or alkaline solutions is low and stays unchanged.

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Simultaneous Adsorption of Chromium and Acidic Dye from Leather Tannery Model Wastewater Using a Novel Modified Nanoclay

10.21203/rs.3.rs-194098/v1 ◽

2021 ◽

Author(s):

Mahsa Golghasemi Sorkhabi ◽

Hassan Aghdasinia ◽

Fatemeh Notghi Oskui ◽

Afzal Karimi ◽

Mortaza Golizadeh

Keyword(s):

Contact Time ◽

Zero Point ◽

Initial Solution ◽

Isotherm Models ◽

Solution Ph ◽

Binary Solutions ◽

Adsorbent Dosage ◽

X Ray ◽

Simultaneous Adsorption ◽

Bet Analysis

Abstract Simultaneous removal of Cr^3+ and acidic dye from model tannery wastewater was investigated using local nano clay modified by 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) surfactant. X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), carbon, hydrogen, nitrogen and sulfur analysis (CHNS), Brunauer-Emmet-Teller (BET) analysis and pH of zero point charge (pH_ZPC) analyses were carried out for characterization of the adsorbent, and adsorptive properties of the modified clay were investigated by batch experiments. The effects of essential parameters, such as adsorbent dosage, initial solution pH, initial solution concentration, contact time, and temperature, were studied. Maximum adsorption values (99.74% for Cr^3+ and 83.26% for dye) were obtained in the following conditions: pH of 4, initial concentration of 100 mg/L, adsorbent dosage of 15000 mg/L, contact time of 30 min. The effect of contaminants’ concentration was also investigated through response surface methodology (RSM), central composite face-centered (CCF) design and an empirical model was presented. The results of kinetic models’ studies demonstrated that simultaneous adsorption of contaminants follows the pseudo-second-order model, and the adsorption data of single and binary solutions fitted nonlinearly to isotherm models showed that the adsorption of Cr (III) from binary and single solutions follow Langmuir and Dubinin-Radushkevitch (D-R) isotherms, respectively. Adsorption of dye from both single and binary solutions follows Redlich- Peterson (R-PT) isotherm. Maximum adsorption capacities were obtained to be 193.1390 mg/g and 144.1782 mg/g for Cr^3+ and dye, respectively. Synergistic and antagonistic adsorptions were observed in binary solutions.

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