Ni/NiO nanopowders with different phase ratio have been prepared using thermal decomposition of nickel acetate ammine complexes containing various ammonia content in air at the temperature range 300 – 500 °C. Obtained powders have been characterized by IR-spectroscopy, XRD and TG, DTA, DTG, TEM, laser granulometry and adsorption-structural method. Thermal decomposition of nickel ammine complexes occurred with forming nickel hydroxide, carbonate and hydroxocarbonate ammines precursors. Composition of the precursors depended on temperature and ammonia content in initial complex. Mean crystallite size of nickel depended on temperature only. In the temperature range from 350 to 500 °C the crystallite size of nickel has grown from 50 to 55 nm. Mean crystallite size of nickel oxide depended on temperature and ammonia content. In the temperature range from 350 to 500 °C the crystallite size of NiO has grown from 5 to 25 nm. Increasing ammonia content from 3.6 to 14.4 mol/mol Ni led to decreasing NiO crystallite size from 8 – 10 to 5 nm.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3512

Dulina, I.O.

Klochkov, L.O.

Lobunets, T.F.

Ragulya, A.V.

SocioEconomic Challenges Journal (Sumy State University)

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  
NANOMATERIALS: APPLICATIONS AND PROPERTIES 
Vol. 2 No 2, 02PCN08 (4pp) (2013) 
 
 
2304-1862/2013/2(2) 02PCN08(4) 02PCN08-1  2013 Sumy State University 
Synthesis of Ni/NiO Nanosize Powders with Different Phase Ratio by Thermal Decomposi-
tion of Nickel Acetate Amines 
 
I.O. Dulina*, T.F. Lobunets, L.O. Klochkov, A.V. Ragulya 
 
Frantsevich Institute for Problems of Materials Science of NASU, 3, Krzhyzhanovsky St., Kyiv, 03142, Ukraine 
 
(Received 19 May 2013; published online 30 August 2013) 
 
Ni/NiO nanopowders with different phase ratio have been prepared using thermal decomposition of 
nickel acetate ammine complexes containing various ammonia content in air at the temperature range 
300 – 500 C. Obtained powders have been characterized by IR-spectroscopy, XRD and TG, DTA, DTG, 
TEM, laser granulometry and adsorption-structural method. Thermal decomposition of nickel ammine 
complexes occurred with forming nickel hydroxide, carbonate and hydroxocarbonate ammines precursors. 
Composition of the precursors depended on temperature and ammonia content in initial complex. Mean 
crystallite size of nickel depended on temperature only. In the temperature range from 350 to 500 С the 
crystallite size of nickel has grown from 50 to 55 nm. Mean crystallite size of nickel oxide depended on 
temperature and ammonia content. In the temperature range from 350 to 500 С the crystallite size of NiO 
has grown from 5 to 25 nm. Increasing ammonia content from 3.6 to 14.4 mol/mol Ni led to decreasing NiO 
crystallite size from 8 – 10 to 5 nm. 
 
Keywords: Nickel Ammine Complexes, Nanopowders, IR-Spectroscopy, XRD Analysis, TG, DTA, DTG, 
Slit Pore Structure. 
 
 PACS numbers: 81.07.Bc, 81.16.Be 
 
 
                                                          
* i_risha@online.ua 
1. INTRODUCTION 
 
Nowadays, nickel powders are widely used as mate-
rials for electrodes manufacturing for multilayered 
ceramic capacitors. The specific capacity of the multi-
layered ceramic capacitors can be increased by thick-
ness decreasing of ceramic and electrode layers and 
increasing number of electrodes. Both metallic and 
dielectric layers of 100 - 200 nm thick have to be manu-
factured from nanosize particles of Ni and BaTiO3. 
Thus, development of Ni nanopowder of 20 nm and less 
is of great importance. 
 
2. MATERIALS AND METODS 
 
Ni/NiO nanopowders with different phase ratio 
have been prepered using thermal decomposition of 
nickel acetate ammine complexes containing various 
ammonia content in air at the temperature range 300 –
 500 C. 
Chemical, phase composition and decomposition 
completeness of the products have been identified by 
IR-spectroscopy, XRD and TG, DTA and DTG, respec-
tively. Mean crystallite and particle size have been 
identified by TEM and laser granulometry and the pore 
size distribution of obtained powders has been meas-
ured by the adsorption-structural method.  
 
3. RESULTS AND DISCATION 
 
Thermal decomposition of nickel ammine complexes 
occurred with forming hydroxide, carbonate and hy-
droxocarbonate ammines nickel-containing precursors 
(fig. 1). Precursors composition was identified by an-
nealing temperature and ammonia content in initial 
complex and effected on Ni/NiO ratio in final powder. 
Temperature raising from 325 to 400 С and ammonia 
content increasing from 3.6 to 14.4 mol/mol Ni led to 
decreasing content of nickel carbonate and hydroxocar-
bonate ammines precursors. 
 
 
Fig. 1 – IR-spectra of nickel acetate hexaammine decomposition 
products obtained at different temperatures 
 
 I.O. DULINA, T.F. LOBUNETS, L.O. KLOCHKOV PROC. NAP 2, 02PCN08 (2013) 
 
 
02PCN08-2 
 
Fig. 2 – XRD patterns of nickel acetate hexaammine decomposition products obtained at different temperatures 
 
Independently on initial complex composition 
complex decomposition process occurred in three stag-
es: 1) primary forming Ni from nickel ammine-
hydroxide complexes, 2) decomposing residual nickel-
containing precursors to NiO and 3) after reducing of 
NiO to Ni by ammonia and organic residuals. Since 
formation of Ni phase can occur with thermal decom-
position of nickel hydroxide ammines only and the 
thermal decomposition of nickel carbonate and hy-
droxocarbonate ammines led to forming NiO, ammo-
nia content increasing resulted inrising nickel yield in 
precursor’s decomposition stage and temperature in-
creasing leads to increasing nickel yield on after re-
ducing nickel oxide to metal nickel stage (fig. 2 – 3). 
Temperature rising more than 400 C accelerated 
reaction of nickel oxidation and led to increasing nickel 
oxide content in powder. 
The first and the second decomposition stages led to 
forming slit pore structure with mean pore diameters 
of 3–4 nm in cases of sufficient annealing temperature 
(350 – 500 C). Ammonia and organic compounds elim-
ination from pores on the second stage led to decreas-
ing particles size that consisted of nickel and nickel 
oxide phases particles. But after reduction NiO to Ni by 
ammonia and organic compounds adsorbed on pore 
surface resulted in rising mean particles size. 
Crystallite size of 5 nm for nickel-containing pre-
cursors had remained unchanged with temperature 
and ammonia content (fig. 4a). Mean crystallite size of 
nickel depended on temperature only. In the tempera-
ture range from 350 to 500 °С the crystallite size of 
nickel has grown from 50 to 55 nm (fig. 5b, 6b). Mean 
crystallite size of nickel oxide depended on temperature 
and ammonia content. In the temperature range from 
350 to 500 °С the crystallite size of NiO has grown from 
5 to 25 nm (fig. 4b, 5a, 6a). Increasing ammonia con-
tent from 3.6 to 14.4 mol/mol Ni led to decreasing NiO 
crystallite size from 8–10 to 5 nm (fig. 7, 8). 
 
4. CONCLUSIONS 
 
1. Thermal decomposition of nickel ammine com-
plexes occurred with forming hydroxide, carbonate and 
hydroxocarbonate ammines nickel-containing precur-
sors. Composition of the precursors depended on tem-
perature and ammonia content in initial complex. 
2. Decomposition process occurred in three stages: 
1) primary forming Ni from nickel ammine-hydroxide 
complexes, 2) decomposing residual nickel-containing 
precursors to NiO and 3) after reducing of NiO to Ni by 
ammonia and organic residuals independently on ini-
tial complex composition. 
3. Formation of metal nickel phase can occur with 
thermal decomposition of nickel hydroxide ammine only. 
4. Ammonia content increasing led to increasing 
nickel yield in precursor’s decomposition stage and 
temperature increasing resulted in rising of nickel 
yield on after reducing NiO to Ni stage. 
5. Mean crystallite size of nickel depended on temper-
ature only. In the temperature range from 350 to 500 °С 
the crystallite size of nickel has grown from 50 to 55 nm. 
6. Mean crystallite size of nickel oxide depended on 
temperature and ammonia content. In the temperature 
range from 350 to 500 °С the crystallite size of NiO has 
grown from 5 to 25 nm. Increasing ammonia content 
from 3.6 to 14.4 mol/mol Ni led to decreasing NiO crys-
tallite size from 8–10 to 5 nm. 
7. Particle size of 5 nm for nickel hydroxide ammine 
remained unchanged with temperature and ammonia 
content. 
 SYNTHESIS OF NI/NIO NANOSIZE POWDERS … PROC. NAP 2, 02PCN08 (2013) 
 
 
02PCN08-3 
 
 
Fig. 3 – XRD patterns of Ni/NiO nanopowder obtained at different ammonia content in initial complex 
 
 
 
 
 
Fig. 4 – TEM micrographs of powder obtained with ammonia 
content 7.17 mol/mol Ni at 350 °С: a - nickel hydroxide 
amine precursor; b – NiO 
 
 
 
 
 
 
Fig. 5 – HR TEM micrographs of powder obtained from com-
plex with ammonia content 7.17 mol/mol Ni at 400 °С: a - 
NiO; b – Ni 
a 
b 
a 
b 
 I.O. DULINA, T.F. LOBUNETS, L.O. KLOCHKOV PROC. NAP 2, 02PCN08 (2013) 
 
 
02PCN08-4 
   
 
 a  b 
 
Fig. 6 – TEM micrographs of powder obtained with ammonia content 7.17 mol/mol Ni at 500 С: a - NiO; b – Ni 
 
  
 
Fig. 7 – NiO particles TEM micrographs of powder obtained 
with ammonia content 3.6 mol/mol Ni at 400 °С 
  
 
Fig. 8 – NiO particles TEM micrographs of powder obtained 
with ammonia content 14.4 mol/mol Ni at 400 °С 
 
AKNOWLEDGEMENTS 
 
Authors are grateful to the State Agency on Sci-
ence, Innovations and Informatization of Ukraine for 
a financial support for the project NN352-2012. 


Synthesis of Ni/NiO Nanosize Powders with Different Phase Ratio by Thermal Decomposition of Nickel Acetate Amines

Electronic Sumy State University Institutional Repository

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  NANOMATERIALS: APPLICATIONS AND PROPERTIES Vol. 2 No 2, 02PCN08 (4pp) (2013)   2304-1862/2013/2(2) 02PCN08(4) 02PCN08-1  2013 Sumy State University Synthesis of Ni/NiO Nanosize Powders with Different Phase Ratio by Thermal Decomposi-tion of Nickel Acetate Amines  I.O. Dulina*, T.F. Lobunets, L.O. Klochkov, A.V. Ragulya  Frantsevich Institute for Problems of Materials Science of NASU, 3, Krzhyzhanovsky St., Kyiv, 03142, Ukraine  (Received 19 May 2013; published online 30 August 2013)  Ni/NiO nanopowders with different phase ratio have been prepared using thermal decomposition of nickel acetate ammine complexes containing various ammonia content in air at the temperature range 300 – 500 C. Obtained powders have been characterized by IR-spectroscopy, XRD and TG, DTA, DTG, TEM, laser granulometry and adsorption-structural method. Thermal decomposition of nickel ammine complexes occurred with forming nickel hydroxide, carbonate and hydroxocarbonate ammines precursors. Composition of the precursors depended on temperature and ammonia content in initial complex. Mean crystallite size of nickel depended on temperature only. In the temperature range from 350 to 500 С the crystallite size of nickel has grown from 50 to 55 nm. Mean crystallite size of nickel oxide depended on temperature and ammonia content. In the temperature range from 350 to 500 С the crystallite size of NiO has grown from 5 to 25 nm. Increasing ammonia content from 3.6 to 14.4 mol/mol Ni led to decreasing NiO crystallite size from 8 – 10 to 5 nm.  Keywords: Nickel Ammine Complexes, Nanopowders, IR-Spectroscopy, XRD Analysis, TG, DTA, DTG, Slit Pore Structure.   PACS numbers: 81.07.Bc, 81.16.Be                                                             * i_risha@online.ua 1. INTRODUCTION  Nowadays, nickel powders are widely used as mate-rials for electrodes manufacturing for multilayered ceramic capacitors. The specific capacity of the multi-layered ceramic capacitors can be increased by thick-ness decreasing of ceramic and electrode layers and increasing number of electrodes. Both metallic and dielectric layers of 100 - 200 nm thick have to be manu-factured from nanosize particles of Ni and BaTiO3. Thus, development of Ni nanopowder of 20 nm and less is of great importance.  2. MATERIALS AND METODS  Ni/NiO nanopowders with different phase ratio have been prepered using thermal decomposition of nickel acetate ammine complexes containing various ammonia content in air at the temperature range 300 – 500 C. Chemical, phase composition and decomposition completeness of the products have been identified by IR-spectroscopy, XRD and TG, DTA and DTG, respec-tively. Mean crystallite and particle size have been identified by TEM and laser granulometry and the pore size distribution of obtained powders has been meas-ured by the adsorption-structural method.   3. RESULTS AND DISCATION  Thermal decomposition of nickel ammine complexes occurred with forming hydroxide, carbonate and hy-droxocarbonate ammines nickel-containing precursors (fig. 1). Precursors composition was identified by an-nealing temperature and ammonia content in initial complex and effected on Ni/NiO ratio in final powder. Temperature raising from 325 to 400 С and ammonia content increasing from 3.6 to 14.4 mol/mol Ni led to decreasing content of nickel carbonate and hydroxocar-bonate ammines precursors.   Fig. 1 – IR-spectra of nickel acetate hexaammine decomposition products obtained at different temperatures   I.O. DULINA, T.F. LOBUNETS, L.O. KLOCHKOV PROC. NAP 2, 02PCN08 (2013)   02PCN08-2  Fig. 2 – XRD patterns of nickel acetate hexaammine decomposition products obtained at different temperatures  Independently on initial complex composition complex decomposition process occurred in three stag-es: 1) primary forming Ni from nickel ammine-hydroxide complexes, 2) decomposing residual nickel-containing precursors to NiO and 3) after reducing of NiO to Ni by ammonia and organic residuals. Since formation of Ni phase can occur with thermal decom-position of nickel hydroxide ammines only and the thermal decomposition of nickel carbonate and hy-droxocarbonate ammines led to forming NiO, ammo-nia content increasing resulted inrising nickel yield in precursor’s decomposition stage and temperature in-creasing leads to increasing nickel yield on after re-ducing nickel oxide to metal nickel stage (fig. 2 – 3). Temperature rising more than 400 C accelerated reaction of nickel oxidation and led to increasing nickel oxide content in powder. The first and the second decomposition stages led to forming slit pore structure with mean pore diameters of 3–4 nm in cases of sufficient annealing temperature (350 – 500 C). Ammonia and organic compounds elim-ination from pores on the second stage led to decreas-ing particles size that consisted of nickel and nickel oxide phases particles. But after reduction NiO to Ni by ammonia and organic compounds adsorbed on pore surface resulted in rising mean particles size. Crystallite size of 5 nm for nickel-containing pre-cursors had remained unchanged with temperature and ammonia content (fig. 4a). Mean crystallite size of nickel depended on temperature only. In the tempera-ture range from 350 to 500 °С the crystallite size of nickel has grown from 50 to 55 nm (fig. 5b, 6b). Mean crystallite size of nickel oxide depended on temperature and ammonia content. In the temperature range from 350 to 500 °С the crystallite size of NiO has grown from 5 to 25 nm (fig. 4b, 5a, 6a). Increasing ammonia con-tent from 3.6 to 14.4 mol/mol Ni led to decreasing NiO crystallite size from 8–10 to 5 nm (fig. 7, 8).  4. CONCLUSIONS  1. Thermal decomposition of nickel ammine com-plexes occurred with forming hydroxide, carbonate and hydroxocarbonate ammines nickel-containing precur-sors. Composition of the precursors depended on tem-perature and ammonia content in initial complex. 2. Decomposition process occurred in three stages: 1) primary forming Ni from nickel ammine-hydroxide complexes, 2) decomposing residual nickel-containing precursors to NiO and 3) after reducing of NiO to Ni by ammonia and organic residuals independently on ini-tial complex composition. 3. Formation of metal nickel phase can occur with thermal decomposition of nickel hydroxide ammine only. 4. Ammonia content increasing led to increasing nickel yield in precursor’s decomposition stage and temperature increasing resulted in rising of nickel yield on after reducing NiO to Ni stage. 5. Mean crystallite size of nickel depended on temper-ature only. In the temperature range from 350 to 500 °С the crystallite size of nickel has grown from 50 to 55 nm. 6. Mean crystallite size of nickel oxide depended on temperature and ammonia content. In the temperature range from 350 to 500 °С the crystallite size of NiO has grown from 5 to 25 nm. Increasing ammonia content from 3.6 to 14.4 mol/mol Ni led to decreasing NiO crys-tallite size from 8–10 to 5 nm. 7. Particle size of 5 nm for nickel hydroxide ammine remained unchanged with temperature and ammonia content.  SYNTHESIS OF NI/NIO NANOSIZE POWDERS … PROC. NAP 2, 02PCN08 (2013)   02PCN08-3   Fig. 3 – XRD patterns of Ni/NiO nanopowder obtained at different ammonia content in initial complex      Fig. 4 – TEM micrographs of powder obtained with ammonia content 7.17 mol/mol Ni at 350 °С: a - nickel hydroxide amine precursor; b – NiO       Fig. 5 – HR TEM micrographs of powder obtained from com-plex with ammonia content 7.17 mol/mol Ni at 400 °С: a - NiO; b – Ni a b a b  I.O. DULINA, T.F. LOBUNETS, L.O. KLOCHKOV PROC. NAP 2, 02PCN08 (2013)   02PCN08-4      a  b  Fig. 6 – TEM micrographs of powder obtained with ammonia content 7.17 mol/mol Ni at 500 С: a - NiO; b – Ni     Fig. 7 – NiO particles TEM micrographs of powder obtained with ammonia content 3.6 mol/mol Ni at 400 °С    Fig. 8 – NiO particles TEM micrographs of powder obtained with ammonia content 14.4 mol/mol Ni at 400 °С  AKNOWLEDGEMENTS  Authors are grateful to the State Agency on Sci-ence, Innovations and Informatization of Ukraine for a financial support for the project NN352-2012. 

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Synthesis of Ni/NiO Nanosize Powders with Different Phase Ratio by Thermal Decomposition of Nickel Acetate Amines

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