4th EucheMs chemistry congress

Poster Session 2
s1196
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - solid state chemistry
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StudieS on uLtrASound-ASSiSted SyntheSiS of
hiGhLy diSPerSed MAnGAneSe doPed zinC
SuLPhide PowderS
A. i. CAdiS 1 , e. J. PoPoviCi 1 , i. PerhAitA 1 ,
L. BArBu-tudorAn 2 , L. e. MureSAn 1
1 Babes-Bolyai University, “Raluca Ripan” Institute for
Research in Chemistry, Cluj-Napoca, Romania
2 Babes-Bolyai University, Electronic Microscopy Center,
Cluj-Napoca, Romania
Due to their special properties, the highly dispersed II-VI
semiconductors account for the most investigated materials. Zinc
sulphide-based materials have attracted increasing interest with respect
to their applications in various domains i.e. optoelectronics [1] .
Through controlling the size and the doping of zinc sulphide
(ZnS) particles with manganese [2] , a different material with new
properties and uses could be obtained.
Because of strongly dependence of powders properties by
synthesis method, a various methods have been developed for the
preparation of un-doped or doped ZnS powders, methods such
chemical precipitation [1] and ultrasound [3] assisted synthesis
routes.
Herein we report the ultra-sound assisted synthesis of highly
dispersed Mn-doped zinc sulphide powders (ZnS:Mn) with
luminescent properties. Synthesis was performed from
zinc-manganese acetate and thioacetamide, in aqueous medium
with controlled pH. Variable manganese concentrations and
different organic additives were used in order to control the
morphostructural and photoluminescence properties..
ZnS:Mn samples were characterized by photoluminescence
spectroscopy (PL), transmission and scanning electron
microscopy (TEM, SEM), X-ray diffraction (XRD) and
inductively coupled plasma optical emission spectroscopy
(ICP-OES).
A correlation between the preparation conditions and
powders characteristics was established.
references:
1. X.J. Zheng, Y.Q. Chen, T. Zhang, C.B. Jiang, B. Yang,
B. Yuan, S.X. Mao, W. Li, Scr. Mater. 62, 520 (2010).
2. A.-I. Cadis, E.-J. Popovici, E. Bica, I. Perhaita,
L. Barbu-Tudoran, E. Indrea Chalcogenide Lett. 7, 631
(2010).
3. A.-R. Tomsa, E.-J. Popovici, A.-I. Cadis, M. Stefan,
L. Barbu-Tudoran, S. Astilean, J. Optoelectron.
Adv. Mater. 10, 2342 (2008).
Keywords: Luminescence; Chalcogens; Doping; Manganese;
Nanoparticles;
4 th EucheMs chemistry congress
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ControLLinG the diSPerSion of
MonoMetALLiC nAnoPArtiCLeS PrePAred By
wAter-hexAne iMPreGnAtion on the
MeSoPorouS SBA-15 SiLiCA
B. drAGoi 1 , C. CiotoneA 1 , A. ChirieAC 1 ,
A. unGureAnu 1 , S. royer 2 , d. duPrez 2 ,
e. duMitriu 3
1 “Gheorghe Asachi” Technical University of Iasi, Organic
Biochemical and Food Engineering Department, Iasi,
Romania
2 Université de Poitiers, LACCO UMR 6503 CNRS, Poitiers,
France
3 “Gheorghe Asachi” Technical University of Iasi, Organic
Biochemical and Food Engineering Department, Iasi,
Romania
The purpose of this study is to prepare highly dispersed
monometallic nanoparticles by impregnation of the mesoporous
SBA-15 with nitrate precursors of copper, nickel and cobalt, and
using water - hexane mixture as solvent. Three monometallic
samples with 5 wt % metal loading were prepared. The calcined
samples were characterized by ICP-OES, FT-IR, XRD at high and
low angles, nitrogen physisorption, and TPR. Preliminary, all the
catalysts were tested in the hydrogenation of cinnamaldehyde
(CNA) to cinnamyl alcohol (CNOL). High angles XRD and TPR
analyses displayed very high dispersion and high reducibility
(T =230 °C), respectively of the supported copper oxide. These
red
results were reflected by the catalytic behavior, after reduction at
350 °C under H flow, that shown a quite active and selective
2
catalyst. Therefore a X =20 mole % and S =40 mole % at
CNA CNOL
X = 10 mole % were obtained for this catalyst. For Co/ and
CNA
Ni/SBA-15 samples XRD and TPR investigations indicated two
types of metal precursors. Therefore, the majority crystalline
phase consisted in the corresponding oxides; typical reflections
of the NiO and Co O were identified in the XRD patterns while
3 4
the TPR profiles display a first reduction peak at 480 °C for highly
dispersed NiO and in low interaction with the support, and
300 °C for Co O . Also, nickel and cobalt (phyllo)silicates phases,
3 4
respectively were observed in both samples and considered as
additional factor which contributes to the good dispersion of metal
nanoparticles. Additional information was provided by FT-IR
spectroscopy which indicated a vibration band at 960 cm-1 attributed to Si-O vibration in 1:1 phyllosilicate. Preliminary tests
in CNA hydrogenation shown active Ni/SBA-15 and inactive
Co/SBA-15 catalysts.
Acknowledgement: B. Dragoi acknowledges the project
PERFORM-ERA “Postdoctoral Performance for Integration in
the European Research Area” (ID-57649), financed by the
European Social Fund-Romanian Government.
Keywords: monometallic supported nanoparticles; waterhexane
impregnation; hydrogenation;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc