Materials Science s a nd Applications, 2011, 2, 1622-1626
doi:10.4236/msa.2011.211215 Published Online November 2011 (http://www.SciRP.org/journal/msa)
A Novel and Simple Route to Synthesis
Nanocrystalline Titanium Carbide via the
Reaction of Titanium Dioxide and Different
Carbon Source
Youjian Chen1, Yongyong Deng1, Hong Zhang1, Lihua Wang3, Jianhua Ma1,2*
1College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China; 2Nanomaterials and Chemistry Key Labo-
ratory, Advanced Materials Research Center of Wenzhou, Wenzhou University, Wenzhou, China; 3Shimadzu International Trading
(Shanghai) Co., Ltd., Guangzhou, China.
Received September 10th, 2011; revised October 25th, 2011; accepted November 6th, 2011.
ABSTRACT
A novel and simple route for synthesizing nanocrystalline ceramic powders in molten salt was introduced in the paper.
Titanium carbide (TiC) was prepared via the reaction of metallic magnesium powders with titanium dioxide (TiO2),
carbon source and molten salt in an autoclave at 650˚C. Carbon source (oxalic acid and citric acid) in this paper was
stable, low toxic and cheap. X-ray powder diffraction (XRD) patterns indicated that the products were cubic TiC.
Scanning electron microscopy (SEM) images showed that the samples consisted of particles with an average size of 200
nm and 100 nm in diameter, respectively. Energy Dispersive Spectrometer (EDS) analysis of the samples suggested the
products contained carbon and titanium elements. The product was also studied by the thermogravimetric analysis
(TGA). It had good thermal stability and oxidation resistance below 350˚C in air.
Keywords: Titanium Carbide, Chemical Synthesis, X-Ray Diffraction, Scanning Electron Microscopy
1. Introduction
It is known that transition metal carbides have found
extensive applications in many fields, such as cutting tools,
wear-resistant parts and high-temperature structural ma-
terials because of their outing properties, such as high
hardness, high melting point, high thermal conductivity,
high strength even at high temperatures, high wear and
corrosion resistance, and a high degree of chemical sta-
bility [1-3]. Recently, much attention has been paid to
their catalytic properties because they exhibit activities
similar to those of the noble metals [4].
Titanium carbide (TiC) is one of the most important
compounds among transition metal carbides, due to its
promising physical and chemical properties, such as a
high melting temperature (3140˚C), a high boiling tem-
perature (4820˚C), high Vickers hardness (28 - 35 GPa),
high Young’s modulus (410 - 450 GPa), low density
(4.93 g·cm–3), high flexure strength (240 - 400 N/mm2),
good thermal conductivity (21 W/m2 × K), high resistance
to corrosion and oxidation, high abrasion resistance, and
high thermal shock resistance [5-8]. So it is widely used
for cutting materials, abrasive, anti-wear and aerospace
materials [9-11]. At the same time, it can also be used as
a substitute for tungsten carbide in cermets because they
have similar properties of high hardness and wear resis-
tance, what’s more, nickel is used as binder for TiC is
cheaper and less toxic than cobalt which WC requires as
a binder [12]. Because of the promising properties and
extensive application of TiC, it is meaningful to synthe-
size nanocrystalline TiC in a simple route at low tempe-
rature and with convenient manipulations.
Traditionally, TiC powders are commercially synthe-
sized via the reaction of titanium dioxide and carbon in
the temperature range of 1700˚C - 2300˚C for 10 - 24 h
[13], it is important to develop new technics to replace
the old method which wastes time and energy. Recently,
some new methods have been used to synthesize titanium
carbide. Chandra et al. [14] synthesized nano-TiC pow-
der using titanium gel precursor and carbon particles in
the range of 1300˚C - 1580˚C for 2 h under argon cover.

A Novel and Simple Route to Synthesis Nanocrystalline Titanium Carbide via the Reaction 1623
of Titanium Dioxide and Different Carbon Source
Qi et al. [15] reported that nanowires TiC was also
successfully synthesized by the reaction of TiO gas with
methane in the presence of a catalyst containing Fe. Tong
et al. [16] reported the thermal plasma method to synthe-
size nano-powders TiC with the average size of the TiC
powders is less than 100 nm. Lee et al. [17] reported
nano-structured TiC was synthesized by liquid-magne-
sium reduction of vaporized TiCl4 + CCl4 solution. David
et al. [18] reported high surface area, porous titanium
carbide (TiC) films have been synthesized employing
physical vapor deposition of titanium at glancing angles
under high vacuum within an ethylene ambient. Patel et
al. [19] reported Silicon-based nanocomposites containing
TiC were synthesized by high-energy mechanical milling
(HEMM).
In this paper, we have developed a new convenient
route to synthesize nanocrystalline TiC in the autoclave
by the reaction of metallic magnesium powders with
TiO2 and carbon source (oxalic acid (C2H2O4) and citric
acid (C6H8O7), separately.) in an autoclave at 650˚C. In
this route, TiO2 is more stable and safe in operation than
other titanium source (e.g. TiCl4) and metallic magne-
sium powders as reductant are also more safe and conve-
nient than other reductants (e.g. metallic sodium). Due to
the whole synthesis route that is carried out in the sealed
autoclave, so it can be obtained that all manipulations are
rather safe and convenient.
2. Experimental
TiC was synthesized by a novel method. All chemicals
were analytical grade and used without further purifi-
cation. Initially, TiO2, metallic magnesium powders (ex-
cessive) and carbon source (oxalic acid (C2H2O4) and
citric acid (C6H8O7), separately), NaCl and MgCl2 were
put into a mortar orderly with continuous stirring. Then
the mixture was transferred to a stainless steel autoclave
that was heated at 650˚C under argon atmosphere and
then cooling to room temperature naturally. The product
was collected and washed with dilute HCl, distilled water,
and absolute ethanol several times to remove all impurity
species and then dried in vacuum at 60˚C for 8 h. Black
powders were obtained.
The obtained samples were analyzed by powder X-ray
diffraction (XRD) on a Bruker D8 Advance X-ray pow-
der diffractometer using Cu K-α radiation (wave-length λ
= 1.54178 Å). 2 theta angles were from 30˚ to 90˚. The
morphologies and EDS analysis of the samples were ob-
served from a JEOL JSM-6700F scanning electron mi-
croscope.
3. Results and Discussion
Figure 1 shows the XRD patterns of the as-prepared
30 40 50 6070 80 90
2Theta/Degress
(a)
(b)
(c)
(d)
(e)
(a): 60 0oC ,10 h (b): 6 50oC ,4h
(c): 6 50oC, 6h (d): 650oC ,8h
(e): TiC,JCPDS Card no .65-8417
111 200 220 311 322
Intensity/A.U
Figure 1. XRD patterns of the as-prepared samples (oxalic
acid as carbon source) and standard pattern.
samples using oxalic acid as carbon source and TiC (JCPDS
Card no. 65-8417). Pattern (a) shows the sample pre-
pared under the condition of 600˚C and 10 h. Obviously,
the sample is not purity with other matters. Pattern (b),
Pattern (c) and Pattern (d) show that the samples are pre-
pared under the condition of 650˚C and 4 h, 6 h and 8 h,
respectively. There are five obvious diffraction peaks in
these patterns. And all these diffraction peaks ((1 1 1), (2
0 0), (2 2 0), (3 1 1), (3 2 2)) at different d-space can be
indexed as cubic titanium carbide (TiC). The refinement
gives the cell constants (a = b = c = 4.326 Å), which is
consistent with the value reported in the literature (a = b
= c = 4.325 Å) (JCPDS card no. 65-8417). No evidences
of impurities such as titanium, titanium dioxide, other ti-
tanium carbides, can be found in these XRD patterns.
Figure 2 shows the XRD patterns of the as-prepared
samples using citric acid as carbon source and TiC
(JCPDS Card no. 65-8808). Pattern (a) shows the sample
was prepared under the condition of 650˚C and 4 h, there
are five obvious diffraction peaks in this pattern. And all
these diffraction peaks ((1 1 1), (2 0 0), (2 2 0), (3 1 1),
(3 2 2)) at different d-space can be indexed as cubic
titanium carbide (TiC). The refinement gives the cell
constants (a = b = c = 4.3213 Å), which is consistent
with the value reported in the literature (a = b = c = 4.316
Å) (JCPDS card no. 65-8808). No evidences of impu-
rities such as titanium, titanium dioxide, other titanium
carbides, can be found in this XRD pattern.
The morphologies of the prepared TiC samples were
investigated by field emission scanning electron micro-
scopy. Figure 3(a), (b), (c) showed the SEM images of
the as-prepared samples using oxalic acid, which were
prepared under the reaction conditions of 650˚C and 4 h,

A Novel and Simple Route to Synthesis Nanocrystalline Titanium Carbide via the Reaction 1624
of Titanium Dioxide and Different Carbon Source
30 40 5060 70 80 90
2Theta/Degree
(b)
(a)
111 200
220
311
322
Intensity/a.u
(a) 650 oC 4h
(b) TiC JCP DS Card no. 65-880 8
Figure 2. XRD patterns of the as-prepared samples (citric
acid as carbon sour ce) and standar d pattern.
Figure 3. SEM images of the as-prepare d samples prepare d
under different reaction conditions ((a), (b) and (c) samples
using oxalic acid, (d) sample using citric acid): (a) 650˚C, 4
h; (b) 650˚C, 6 h; (c) 650˚C, 8 h; (d) 650˚C, 4 h.
6 h, 8 h, respectively. The samples showed that they con-
sisted of particles with an average diameter of 200nm. It
seemed not to affect the particle size of the samples sig-
nificantly, through varying the reaction time at the tem-
perature of 650˚C. Figure 3(d) showed the SEM image
of the as-prepared sample using citric acid, which was
prepared under the reaction conditions of 650˚C and 4 h.
The sample showed that it consisted of particles with an
average diameter of 100 nm. The reaction temperature of
the TiC samples prepared using oxalic acid and citric
acid as carbon source is 650˚C. They maybe have poten-
tial for the economy and efficiency of synthesis of TiC
nanopowders for industrial applications. Compared to ci-
tric acid as carbon source, the size of the particles pre-
pared using oxalic acid as carbon source shows increase.
These particles exhibit slightly agglomerated particle mor-
phology due to the ultrafine size of the sample.
The EDS figures of the prepared TiC samples were
shown in the Figure 4 and Figure 5. The EDS images of
the as-prepared TiC samples were prepared under differ-
rent reaction conditions. Figure 4 showed the sample
was prepared under the condition of 650˚C and 4 h using
oxalic acid as carbon source, and Figure 5 showed the
sample was prepared under the condition of 650˚C and 4
h using citric acid as carbon source. According to the
EDS results, the products are composed of C, Ti, Zn, Cu
elements, without the contamination of oxygen. Both Zn
and Cu come from the copper plateform. It can be con-
cluded that the selectional particulates may be TiC. It can
be found that TiC particulates in a great measure are 200
nm and 100 nm, respectively. Furthermore, the weight
percentage of Titanium and carbon analyzed by EDS
Figure 4. EDS of the sample prepared under the condition
of 650˚C and 4 h using ox alic acid as carbo n sour ce.
Figure 5. EDS of the sample prepared under the condition
of 650˚C and 4 h using citric acid as car bon source.

A Novel and Simple Route to Synthesis Nanocrystalline Titanium Carbide via the Reaction 1625
of Titanium Dioxide and Different Carbon Source
were 55.63:17.90 in the Figure 4 and 60.73:23.29 in the
Figure 5; while the atomic ratio of Titanium and carbon
were 0.77:1.00 and 0.66:1.00, separately.
We are in order to investigate the thermal stability and
the oxidation resistance of the as-prepared TiC powders
using oxalic acid that they were prepared under the con-
dition of 650˚C and 8 h by the thermogravimetric ana-
lysis (TGA), which was carried out at temperatures be-
low 1000˚C under flowing air and nitrogen gases. We
can find that the weight of the product has changed slight-
ly below 400˚C. A weight loss indicates that the sample
might adsorb a little water on the surface. In this stage,
the sample is very stable. After about 400˚C, TiC sample
is found to begin slowly oxidized, which indicates that
the sample is oxidized by oxygen to form titanium oxide
and carbon dioxide, titanium oxides, both stoichiometric
and nonstoichiometric (TiO2, Ti3O5, Ti2O3, TiO) may be
formed during the oxidation process. We can conclude
from the curve of Figure 6 that more quantity of titanium
oxide should be increased along with further oxidation.
As the temperature rises from 400˚C to 850˚C, there is an
obvious weight gain during the process, indicating that
the TiC sample is oxidized into titanium oxide and car-
bon dioxides. Between 850˚C and 920˚C, the carbon dio-
xide generated in the simple surface slowly released may
induce a small weight loss. Above 920˚C, the weight gain
remains almost constant. We also can find that the weight
of the product has changed slightly below 1000˚C under
flowing nitrogen gases, this is because that the sample
might adsorb nitrogen gases on the surface.
It was suggested that reaction temperature had a sig-
nificant influence on the formation of TiC. The XRD pa-
tterns of the as-prepared samples were synthesized under
different temperature, time conditions and different car-
0100 200 300 400 500 600700 800 90010001100
-5
0
5
10
15
20
25
30
35
40
Weight gain /%
Temperature (oC)
(a)
(b)
(a) :flowing air
(b) :flowing nitrogen gases
Figure 6. TGA curves in flowing air and nitrogen gases of
the as-prepared TiC sample using oxalic acid prepared un-
der the condition of 650˚C and 8 h.
bon source. The SEM images of these samples are shown
in Figure 3. From the XRD patterns, we can easily obtain
conclusion that TiC could be synthesised when the re-
action temperature is 600˚C, but the crystallinity is not
very good, and has some impurities such as Ti can be
found in the Figure 1(a). When the temperature is 650˚C,
the crystallinity of the sample is very good, and no evi-
dences of crystal impurities such as titanium, titanium
oxides, other titanium carbides, can be found in these
XRD patterns. An optimum temperature for the forma-
tion of nanocrystalline TiC is about 650˚C. Varying the
reaction time at 650˚C did not significantly affect the
particle size of the as-prepared TiC shown in Figure 3(a)-
(c). However, the carbon source in the reaction processes
can affect the size of the products. Compared to citric
acid as carbon source, the size of the particles prepared
using oxalic acid as carbon source shows increase.
In our experiments, as the temperature rising, C2H2O4
and C6H8O7 could decompose generating carbon oxides
gases. So the pressure in the autoclave may be very high.
The high pressure in the autoclave would be helpful for
reducing the reaction temperature and enhancing the re-
action speed. At the reaction temperature, TiO2, carbon
oxides gases and metallic magnesium powders could re-
act with each other to produce cubic TiC. The total re-
action process can be represented as the following:
2TiO2 + 10Mg + C2H2O4·2H2O → 2TiC + 10MgO + 3H2
C6H8O7 + 19Mg + 6TiO2 → 6TiC + 19MgO + 4H2
4. Conclusions
In summary, nanocrystalline cubic TiC has been pre-
pared via a simple thermal route by the reaction of me-
tallic magnesium powders with titanium dioxide (TiO2)
and carbon source (oxalic acid and citric acid) in molten
salt at 650˚C for 4 h. The product crystalline structure is
cubic. It consists of particles with an average size of 200
nm and 100 nm, respectively. Compared to other carbon
source (e.g. CCl4), carbon source in this paper is stable,
low toxic and cheap, it can be obtained that all manipu-
lations are rather safe and convenient. This simple che-
mical synthesis route maybe provide a new method to
prepare other transition metal carbides.
5. Acknowledgements
This work was supported by Innovation and Promotion
of science-technology project of Zhejiang Province and
Department of Education of Zhejiang Province of China
under Grant No. 20070546.
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