From plates to spheres: Tuning the vanadyl phosphate morphology by intercalation of nitrosyl oxide

Article abstract of DOI:10.1080/15533174.2013.799490

The lamellar matrix VOPO₄.2H₂O was used to the intercalation of nitrosyl (NO) ligand. The vanadyl phosphate matrix, as well as the prepared intercalated compound (VOPO₄.NO.H₂O), were characterized by infrared spectroscopy, thermogravimetry, X-ray difractometry, and SEM microscopy. The X-ray diffraction patterns shown that the VOPO ₄.NO.H₂O synthesis occurs with a decrease in the lamellar distance in comparison with VOPO₄.2H₂O. The SEM micrographs obtained for VOPO₄.2H₂O and VOPO ₄.NO.H₂O shown that microstructure of vanadyl phosphate is flat square whereas the compound VOPO₄.NO.H₂O exhibits spheroid grains. Copyright Taylor & Francis Group, LLC.

Full text of DOI:10.1080/15533174.2013.799490

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From Plates to Spheres: Tuning the Vanadyl Phosphate
Morphology by Intercalation of Nitrosyl Oxide
a
b
c
c
José C. V. de Miranda , Deyse de S. Dantas , João E. T. S. Dantas , Francisco C. Pereira &
c
Robson F. de Farias
a
Faculdade de Educação de Crateús—FAEC, Crateús, Brazil
b
Faculdade Maurício de Nassau, Capim Macio, Natal, Brazil
c
Universidade Federal do Rio Grande do Norte, Natal, Brazil
Accepted author version posted online: 26 Dec 2013.Published online: 17 Apr 2014.
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To cite this article: José C. V. de Miranda, Deyse de S. Dantas, João E. T. S. Dantas, Francisco C. Pereira & Robson F. de Farias
2014) From Plates to Spheres: Tuning the Vanadyl Phosphate Morphology by Intercalation of Nitrosyl Oxide, Synthesis and
(
Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 44:9, 1231-1233, DOI: 10.1080/15533174.2013.799490
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Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 44:1231–1233, 2014
Copyright ꢀC Taylor & Francis Group, LLC
ISSN: 1553-3174 print / 1553-3182 online
DOI: 10.1080/15533174.2013.799490
From Plates to Spheres: Tuning the Vanadyl Phosphate
Morphology by Intercalation of Nitrosyl Oxide
1
2
3
Jos e´ C. V. de Miranda, Deyse de S. Dantas, Jo a˜ o E. T. S. Dantas,
3
3
Francisco C. Pereira, and Robson F. de Farias
Faculdade de Educa c¸ a˜ o de Crate u´ s—FAEC, Crate u´ s, Brazil
Faculdade Maur ´ı cio de Nassau, Capim Macio, Natal, Brazil
Universidade Federal do Rio Grande do Norte, Natal, Brazil
1
2
3
structure and chemical composition of this new molecule en-
The lamellar matrix VOPO .2H
4 2
O was used to the intercala- hance chemical, physical and morphological vanadyl phosphate
tion of nitrosyl (NO) ligand. The vanadyl phosphate matrix, as properties. Furthermore, it was shown that the intercalation of
well as the prepared intercalated compound (VOPO
4
.NO.H
2
O),
2+
+
+
3+
3+
3+
3+
metal ions such as Mn , Li , K , Al , Cr , Fe , Ga ,
and organic molecules such as aniline, can cause changes in
were characterized by infrared spectroscopy, thermogravimetry,
X-ray difractometry, and SEM microscopy. The X-ray diffrac-
its nanostructure and form various compounds with several cat-
On the other hand, studies aimed at
the trapping of inorganic gases are still very incipient and not
4 2
tion patterns shown that the VOPO .NO.H O synthesis occurs
with a decrease in the lamellar distance in comparison with alytic applications.[
1–13]
VOPO
4
.2H
2
O. The SEM micrographs obtained for VOPO
4
.2H
2
O
and VOPO
4
.NO.H O shown that microstructure of vanadyl phos-
2
illuminating.
phate is flat square whereas the compound VOPO4.NO.H2O ex-
hibits spheroid grains.
Due to its uses as catalyst, the morphology of oxovanadium
phosphate grains it an important characteristic to be controlled.
In this connection, in the present work it is shown that the
Keywords nitrosyl oxide, morphology, spheres, vanadyl phosphate
“
regular” shape of VOPO4.2H2O crystals, that is, flat plates, can
be turned into spheres by reaction (intercalation) with nitrosyl
oxide (NO).
INTRODUCTION
Vanadium pentoxide, V2O5, has been used as precursor mate-
rial in the synthesis of vanadyl phosphate, VOPO4.2H2O.[
This compound is one of the catalysts used in the oxidation
1–12]
EXPERIMENTAL
The compound VOPO4.2H2O was prepared according to the
methodology described elsewhere
[
3]
of organic molecules. In VOPO4.2H2O, a central vanadium
[6–12]
: 12.5 g of vanadium pen-
atom is connected to six oxygen atoms, giving a regular octa-
toxide, V2O5 (Aldrich), 111 g of H3PO4 85% (Vetec), 288 mL
of distilled water, and 1.5 mL of HNO3 65% (Vetec) were mixed
under reflux for 16 h. After this period, a yellow solid was ob-
tained and filtered off, washed with acetone, and dried under
vacuum at room temperature.
In order to obtain the complex VOPO4.NO.xH2O, a NO flux
was created by reacting metallic copper with HNO3 6.0 mol/L.
Then, a constant flow of NO gas was bubbled in an aqueous solu-
tion of vanadyl phosphate for 6 h. After this period, the greenish
compound VOPO4.NO.xH2O was precipitated by adding anhy-
drous ethyl alcohol, and then filtered off and dried in a desiccator
at low pressures.
hedral structure.[
4–12]
The organization of the structures form
an open lattice which can accommodate positive ions and/or
organic molecules.[
1–12]
Because of the oxidative properties of
VOPO4.2H2O, when neutral molecules enter the lamellar struc-
ture, they undergo oxidation by transferring one or more elec-
5+
trons to the host species. The chemical species, V , is the
promoter of such oxidative processes, especially for organic
molecules.[
4–12]
The vanadyl phosphate is a lamellar compound and therefore
able to accommodate> in their nanostructure molecules of small
[4–12]
dimensions. In the literature
is reported that changes in the
TG analyses were performed using a Shimadzu TG-50 ap-
paratus. Curves were recorded over a range of temperatures up
◦
◦
−1
Received 4 April 2013; accepted 22 April 2013.
to 900 C at a heating rate of 5 C min on N2 atmosphere.
The FT-IR spectra were obtained in a PerkinElmer apparatus,
Address correspondence to Robson F. de Farias, Universidade Fed-
eral do Rio Grande do Norte, Cx. Postal 1664, 59078-970, Natal, RN,
Brazil. E-mail: robdefarias@yahoo.com.br
Color versions of one or more of the figures in the article can be
found online at www.tandfonline.com/lsrt.
−1
model Spectrum 65 in KBr discs (4000–400 cm ).
The X-ray diffraction patterns were obtained in a Rigaku
◦
diffractometer model Miniflex II, with a scan rate of 5 /min,
1231

1232
J. C. V. DE MIRANDA ET AL.
FIG. 2. Infrared spectra for VOPO4.2H2O (a) and VOPO4.NO.H2O (b).
The infrared spectrum, shown in Figure 2, presented the
principal bands for VOPO4.2H2O located at 3580, 1626, 1093,
−1
9
46, and 685 cm , due to the υ(OH), δ(OH), υas(P-O),
FIG. 1. X-ray diffraction patterns for VOPO4.2H2O (a) and VOPO4.NO.H2O υ(V-O), and δ(V-OH) or (P-OH) vibration modes, respec-
tively, as has been previously assigned.[
6–12]
For the compound
(
b).
VOPO4.NO.H2O the main characteristic peak is of that at
−
1
1
383 cm (asymmetric stretching) as shown in Figure 2, indi-
angle equal to 0.05 with the step, the applied voltage of 15 kV,
and current of 15 mA, using Cu detector.
The SEM images were obtained using a microscope Phillips
model XL30-ESEM.
cating the presence of NO species in the chemical structure of the
compound.
The profile of the absorption bands due to the VOPO4 lattice
vibration around 1100 cm was retained after reaction, provid-
−1
ing evidence that an intercalation compound and not merely a
salt of V-P-O species was produced.[
6–12]
This infrared data, on
RESULTS AND DISCUSSION
The X-ray diffraction pattern for VOPO4.2H2O is shown in the other hand, supports the X-ray diffraction ones.
Figure 1. The main peaks observed in the XRD pattern are in
The SEM images obtained for VOPO4.2H2O and
VOPO4.NO.H2O are presented in Figure 3. The compounds
[
1–12]
agreement with those previously reported in the literature,
◦
◦
◦
with characteristic peaks at 11.7 , 18.6 , and 23.8 , associated exhibit distinct morphologies. The compound VOPO4.2H2O,
with the (001), (101), and (002) diffraction planes, respectively. comes in the form of square plates with slightly varying sizes,
From the 001 plane, an interlayer distance of 0.75 nm can be while the compound VOPO4.NO.H2O displays morphological
calculated.
structure similar to regular-sized spheres. The proposal for the
Powder X-ray diffraction pattern for VOPO4.NO.H2O is arrangement of the nitrosyl ligand in the structure of vanadyl
shown in Figure 1. The 001 plane diffraction peak is dislo- phosphate is schematically shown in Figure 4.
cated to 12.19. So, the intercalation of NO implies in a decrease
of the interlayer distance.
The thermogravimetric curves and their derivatives, ob-
tained for VOPO4.2H2O and VOPO4.NO.H2O are presented in

VANADYL PHOSPHATE, NITROSYL OXIDE, SPHERES
1233
FIG. 4. Arrangement proposed for the intercalation of the NO molecule in the
structure of vanadyl phosphate.
FIG. 5. TG curves for VOPO4.2H2O (a) and VOPO4.NO.H2O (b).
loss can be attributed to the release of interlayer water molecules,
and the second mass loss to the coordinated ones.[
6–12]
The thermogravimetric curve for VOPO4.NO.H2O is shown
in Figure 5. The main mass loss in this curve is that in the
◦
3
72–400 C range, associated with the release of NO molecules
coordinated to vanadium. So, in comparing Figure 5 it can be
concluded that the coordinative covalent bond NO-V is stronger
than the H2O-V bond.
FIG. 3. SEM micrographs for VOPO4.2H2O (a) and VOPO4.NO.H2O (b).
REFERENCES
1
2
3
. Bordes, E.; Courtine, P. J. Catal. 1979, 57, 236.
. Guliantes, V. V.; Benziger, J. B.; Sundaresan, S. J. Catal. 1995, 156, 298.
. Ait-Lachgar, K.; Truel, A.; Brun, M.; Herrmann, J. M.; Krafft, J. M.; Martin,
J. R.; Volta, J. C.; Abon, M. J. Catal. 1998, 177, 224.
Figure 5. As can be seen in Figure 5 vanadyl phosphate exhibits
shows two mass loss steps in the 77–124 C range. The first
one is associated with dehydration, forming the monohydrate
◦
4. De Farias, R. F. Quim. Nova 2003, 26, 493.
5. Okahara, T.; Ryumon, N.; Yamamoto, N.; Hiyoshi, N. Sci. Technol. Catal.
2
002, 55, 271.
(
VOPO4.2H2O → VOPO4.H2O + H2O), and the second one
6. De Farias, R. F.; Chemistry on Modified Oxide and Phosphate Surfaces:
is associated with the formation of the anhydrous compound:
Fundamentals and Applications; Academic Press, Amsterdam, 2009.
[6–12]
VOPO4.H2O → VOPO4 + H2O).
Two types of molecules
7. De Farias, R. F.; Airoldi, C. J. Solid State Chem. 2002, 166, 277.
. De Farias, R. F.; Airoldi, C. Solid State Sci. 2003, 5, 611.
8
are present in VOPO4.2H2O: one water molecule is coordi-
nated to vanadium, in a trans position to the V O group.[6–12]
9. De Farias, R. F.; Airoldi, C. J. Serbian Chem. Soc. 2005, 70, 1283.
0. Machado, M. O.; De Farias, R. F.; Airoldi, C. J. Phys. Chem. Solids 2004,
1
The other one is situated between the layers, and both water
molecules hold the layers together by hydrogen bonding to the
6
5, 1697.
1
1. De Farias, R. F.; Mens Agitat 2007, 2, 61.
oxide framework. Based on these considerations, the first mass 12. De Farias, R. F.; Airoldi, C. Quim. Mater. 2011, 1, 21.