The role of Cu 2+ concentration in luminescence quenching of Eu 3+ / Cu 2+ co-doped ZrO2 nanoparticles

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The role of Cu 2+ concentration in luminescence quenching of Eu 3+ / Cu 2+ co-doped ZrO2 nanoparticles. This paper the role of Cu 2+ concentrations in luminescence quenching of Eu 3+ / Cu 2+ doped ZrO2 nanoparticles synthesized by co-precipitation method. The synthesized Eu 3+ / Cu 2+ doped ZrO2 nanoparticles were observed to have sphere morphology with a diameter of 25 nm.
VNU Journal of Science: Mathematics Physics, Vol. 35, No. 1 (2019) 70-75
Original article
The Role of Cu 2+ Concentration in Luminescence Quenching
of Eu 3+ / Cu 2+ Co-doped ZrO2 Nanoparticles
Pham Van Huan1, Phuong Dinh Tam1, 2, *, Nguyen Thi Ha Hanh3,
Cao Xuan Thang1, Vuong-Hung Pham1, *
1Advanced Institute for Science and Technology (AIST), Hanoi University of Science and Technology
(HUST), )01 Dai Co Viet, Hanoi, Vietnam
2 Faculty of Material Science and Engineering, Phenikaa University, Yen Nghia, Hanoi, Viet Nam
3 School of Chemical Engineering, Hanoi University of Science and Technology (HUST),
01 Dai Co Viet, Hanoi, Vietnam
Received 25 January 2019
Revised 20 March 2019; Accepted 21 March 2019
Abstract: This paper the role of Cu 2+ concentrations in luminescence quenching of Eu 3+ / Cu 2+
doped ZrO2 nanoparticles synthesized by co-precipitation method. The synthesized Eu 3+ / Cu 2+
doped ZrO2 nanoparticles were observed to have sphere morphology with a diameter of 25 nm.
The XRD patterns of the nanoparticles revealed the peaks that were to be crystalline tetragonal
ZrO2. The addition of Cu 2+ to the Eu 3+ doped ZrO2 nanoparticles resulted in a significant suppress
luminescence in Eu 3+ / Cu 2+ doped ZrO2 nanoparticles, which was attributed to the spectral
overlap occurs between Cu 2+ absorption and Eu 3+ emission (5D07F2 transition).
Keywords: Zirconia; luminescence; precipitation; quenching, nanoparticles.
1. Introduction
Zirconia (ZrO2) nanoparticles have received considerable attention in optoelectronic materials
because of its high refractive index, optical transparency, corrosion resistance, photothermal stability,
high thermal expansion coefficient, low thermal conductivity, high thermomechanical resistance, and
catalysis [1, 2]. In addition, the stretching energy of ZrO2 is very low that opens up the possibility of
higher efficient luminescence of activator ions incorporated into host ZrO2 matrix [3, 4]. While it is
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Corresponding author.
https//doi.org/ 10.25073/2588-1124/vnumap.4320
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P.V. Huan et al. / VNU Journal of Science: Mathematics Physics, Vol. 35, No. 1 (2019) 70-75
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generally accepted that doping Eu 3+ and Er 3+ ions into ZrO2 nanoparticles tailors the luminescence of
ZrO2 nanoparticles [5, 6]. An alternate approach to producing luminescence with tailoring the light
emission capabilities is to manipulate the matrix to control energy transfer [7, 8].
Previous studies
reported that luminescence quenching for Eu 3+ emission was obtained by doping Cu 2+ in ZnO [9] and
glass matrix [10]. In particular, in our knowledge, there are no reports on the luminescence quenching
for Eu 3+ / Cu 2+ doped ZrO2 nanoparticles. Therefore, this study proposes a report for suppressing
luminescence in Eu 3+ emission (5D07F2 transition) by introducing Cu 2+ into ZrO2 matrix. The
microstructure and crystal structure of the Eu 3+ / Cu 2+ doped ZrO2 nanoparticles were characterized
by X-ray diffraction (XRD, D8 Advance, Bruker) and field emission scanning electron microscopy
(FE−SEM, JEOL, JSM−7600F, JEOL Techniques), respectively. Light emission of nanowire was also
determined by photoluminescence spectrometer (NANO LOG spectrofluorometer, Horiba).
2. Experimental procedure
Eu 3+ / Cu 2+ doped ZrO2 nanoparticles were synthesized through a co-precipitation method, as
follows: ZrOCl2.8H2O (99 % purity, Aldrich, Saint Louis, US), CuCl2.2H2O (99.9 %, Aldrich, Saint
Louis, Mỹ), and CTAB (99.9 %, Merck) was dissolved in distilled water (DW) under vigorous stirring
at 25 oC for 30 min to obtain A solution. Eu(NO3)3 were obtained by dissolving stoichiometric Eu2O3
(99 % purity, Aldrich) in dilute HNO3 with vigorous stirring. Various amount (0, 1, 3, 5, 7, 10 and 15
% mol Cu 2+) were used in all the set of the experiments, whereas, the sample was prepared according
to the above procedure with the fixed amount of 5 % mol Eu 3+. The reaction mixture was further
stirred for 0.5 h at 80 oC and pH was adjusted to 11 by using aqueous ammonia solution (Duc Giang
Chemicals, Hanoi, Vietnam). The resulting precipitates were washed three times and then dried at 600 oC
for 2 h.
The crystalline structures of the Eu 3+ / Cu 2+ doped ZrO2 nanoparticles were characterized by X-
ray diffraction (XRD, D8 Advance, Bruker, Germany). The microstructure and chemical composition of
the Eu 3+/ Cu 2+ doped ZrO2 nanoparticles were determined by field emission scanning electron microscopy
(JEOL, JSM−7600F, JEOL Techniques, Tokyo, Japan) and energy dispersive X-ray spectroscopy (EDS,
Gatan, UK).
To investigate the absorption properties of Eu 3+ / Cu 2+ doped ZrO2 nanoparticles, spectra
were recorded in the wavelength of 200 to 800 nm using UV-Vis spectroscopy (Cary 5000, Varian).
Photoluminescence (PL) tests were performed to evaluate the optical properties of Eu 3+ / Cu 2+ doped ZrO2
nanoparticles. NANO LOG spectrofluorometer (Horiba, USA) equipped with 450 W Xe arc lamp and
double excitation monochromators was used. The PL spectra were recorded automatically during the
measurements.
3. Results and discussions
Figure 1 show the typical XRD patterns of the Eu 3+ / Cu 2+ doped ZrO2 nanoparticles synthesized
by co-precipitation with different Cu 2+ concentrations in the reaction solution. All the Eu 3+ / Cu 2+
doped ZrO2 nanoparticles showed several strong peaks at 2θ = 30.2 o, 35.4 o, 50.3 o, 60.2 o, and 62.7 o
associated with the (001), (200), (112), (121) and (202) plane of the crystalline tetragonal ZrO2
(JCPDS 50-1089, (Fig 1 (b) - (e)). However, the Eu 3+ doped ZrO2 nanoparticles synthesized without
the addition of Cu 2+ showed peaks attributed to the crystalline tetragonal ZrO2 structure (JCPDS (50-
1089) with additional peak at 2θ ≈ 28.4o corresponded to the (-111) planes of the crystalline
monoclonal ZrO2 structure (JCPDS 37-1484), (Fig 1 (a)). These results indicate that the Eu 3+ doped
ZrO2 nanoparticles synthesized with the addition of Cu 2+ via a co-precipitation method had the
preferential formation of tetragonal phase. It is also can be seen that XRD patterns obtained for all of