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Synthesis and characterization of zirconium carbide nanorods at low temperature
Int. Journal of Refractory Metals and Hard Materials 56 (2016) 59–62
Contents lists available at ScienceDirect
Int. Journal of Refractory Metals and Hard Materials journal homepage: www.elsevier.com/locate/IJRMHM
Synthesis and characterization of zirconium carbide nanorods at low temperature Mohammad Mahdavi a,⁎, Mazaher Ramazani b, Zahra Darvishi a a b
Department of Chemistry, Malek-ashtar University of Technology, Shahin-shahr, P.O. Box 83145/115, Islamic Republic of Iran Department of Materials Engineering, Malek-ashtar University of Technology, Islamic Republic of Iran
a r t i c l e
i n f o
Article history: Received 21 September 2015 Received in revised form 9 November 2015 Accepted 18 November 2015 Available online 18 December 2015 Keywords: Zirconium carbide Nanorod Low temperature Nanoparticles Ceramics
a b s t r a c t A novel chemical synthetic method at low temperature was developed for the synthesis of ZrC nanorods, using ZrCl4 and sodium metal in the presence of naphthalene as the carbon source. The results showed that the ZrCl4, after heat treatment in argon atmosphere at temperatures above 500°C, can be completely converted into ZrC nanorods. However, the initial formation temperature of ZrC was as low as 400 °C whereas ZrO2 as an intermediate product was also produced from the precursor at 300°C, and the mixture was finally transformed into pure ZrC at 700°C. The synthesized ZrC nanorods exhibited cubic lattice structure. © 2015 Elsevier Ltd. All rights reserved.
1. Introduction ZrC is one of the large families of highly refractory interstitial compounds with the NaCl-type structure [1]. ZrC has attracted considerable interest due to its various unique properties, such as high hardness, high melting point, high chemical stability and high resistance to radiation, which makes it suitable for many applications, such as field emitters, coating of nuclear fuels and cutting tools [2,3]. Several different synthetic methods have been developed for the synthesis of ZrC, such as carbothermic reduction of ZrO2 at elevated temperatures [4], solutionbased processing at low temperature [5], mechanochemical reaction of Zr and C [6,7], solid state metathesis route [8], preceramic polymer method [9], Mg-thermite method [10] and co-reduction method [11,12]. Metal carbide nanorods play a noteworthy role in leading scientific and industrial research of nanotechnology [13]. Nowadays these nanorods are being studied widely, due to their improved mechanical and physical properties [14]. In the present work, for the first time we develop a simple method to prepare ZrC nanorods at low-temperature using ZrCl4 and naphthalene as carbon source material.
condensation into toluene under argon atmosphere. The crystal structure and phase identity of ZrC nanorods were determined by X-ray diffraction (XRD) using a Bruker D8 ADVANCE instrument. Field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis (EDAX) studies were done on SEM Philips XL30. 2.1. Preparation of ZrC All the reactions were carried out under argon atmosphere. In a typical experimental procedure, appropriate amounts of ZrCl4 (4.82 g) and naphthalene (2.23-g) were dissolved in minimum volume of toluene in a steel reactor. The reagents were stirred at 100 °C after that slightly excessive of Na (1.95 g) was added into the solution and stirring was continued to evaporate toluene until a brown solid remained. The brown solid was heated in an electric furnace at various temperatures (200, 300, 400, 500, 600 and 700 °C) under argon atmosphere for 1 h and then cooled to room temperature. The products were crushed and washed several times with distilled water to remove NaCl, until a silver nitrate test showed that chlorine was completely eliminated. The product was dried in vacuum at 200 °C for 30 min.
2. Materials and methods
3. Results and discussion
Chemicals including sodium metal (99.7%) and naphthalene (99.98%) were used as received. ZrCl4 (98%) was purified by sublimation and
The phase identity and phase mixture of the products obtained at various temperatures were characterized by XRD analysis (Fig. 1). After heat treatment at 300 °C, the product of the reaction was mainly t-ZrO2 (tetragonal ZrO2). When the heat treatment temperature increased to 400 °C, both m-ZrO2 (monoclinic ZrO2) and t-ZrO2 were
⁎ Corresponding author. E-mail address: [email protected] (M. Mahdavi).
http://dx.doi.org/10.1016/j.ijrmhm.2015.11.015 0263-4368/© 2015 Elsevier Ltd. All rights reserved.
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M. Mahdavi et al. / Int. Journal of Refractory Metals and Hard Materials 56 (2016) 59–62
Fig. 1. XRD patterns of ZrCl4–naphthalene reactions at different temperatures.
detected, indicating that some t-ZrO2 had transformed to m-ZrO2. Meanwhile, the initial formation of ZrC was observed at 400 °C. There were no diffraction peaks of graphite in the patterns. At temperatures above 400 °C, all t-ZrO2 had transformed to m-ZrO2, and the intensity of ZrC peaks was increased. At 700 °C, m-ZrO2 phase disappeared completely and ZrC was the only crystalline phase. The XRD pattern exhibited characteristic peaks at 2θ 33.1°, 38.4°, 55.4°, 65.9° and 69.3°, which conformed the formation of ZrC to cubic lattice structure.
Fig. 2 shows FE-SEM micrographs of ZrC nanorods, synthesized at 700 °C. The average diameter sizes of nanocrystallites were different but they had high aspect ratios. The ZrC nanorods were substantially straight and the same along the length of the nanorods. It seems that in addition to carbon source, naphthalene facilitate the reaction through a dissolution process of sodium metal and formation of sodium naphthalenide (Na+ C10H− 8 ). This active intermediate reacts well with ZrCl4 vapor along the ZrC nanorods.
Fig. 2. FE-SEM micrographs of ZrC nanorods.
Fig. 3. XRD pattern of Zr–carbon reaction at 700 °C.
M. Mahdavi et al. / Int. Journal of Refractory Metals and Hard Materials 56 (2016) 59–62
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Fig. 4. FE-SEM micrographs of Zr nanoparticles.
Fig. 5. EDAX analysis of zirconium metal.
To investigate the role of the carbon source, the graphite powder was used as a carbon source instead of naphthalene, for the production of zirconium carbide at various temperatures (200, 300, 400, 500, 600 and 700 °C) under argon atmosphere for 1 h. In this new condition the product was zirconium powder. The phase identity and phase mixture of the product obtained at 700 °C were merely Zr metal based on the XRD analysis (Fig. 3). The FE-SEM micrographs show the morphology and particle size of zirconium nanoparticles with sizes between 50 and 70 nm (Fig. 4). The EDAX analysis was performed to further confirm the phase identity of the product obtained of the as-prepared Zr powder (Fig. 5). The spectrum shows that the sample contains Zr, after washing with distilled water and drying. 4. Conclusions In summary, we succeeded in synthesizing ZrC through the reduction of ZrCl4 and naphthalene with sodium metal at low temperatures. An in situ template reduction-carbonization mechanism is proposed for creation of ZrC nanorods. It is believed that such a method could be extended to fabricate similar nanostructures for other important carbides such as TiC and SiC. These materials suggest exciting opportunities for both essential research and technological applications. Low-temperature synthesis of ZrC has many advantages including the controllable crystalline size, and chemical composition of the final product. The method provides zirconium carbide nanorods on a large scale, and is easy to scale up due to the inexpensive and unlimited availability of reagents.
The small diameter and high aspect ratio of the ZrC nanorods also make them useful as improved reinforcements in metals, ceramics, and polymer matrix composites. The ZrC nanorods can be used in particular products such as cutting tools, engineering composites including gas turbine blades, high strength ceramics, and unique building blocks for new nanomaterials with interesting physical properties. The ZrC nanorods can be used as abrasives or in wear resistant surfaces. These nanorods can also be used as new probe tips for atomic force microscopy (AFM) or biology. References [1] A.C. Lawson, D.P. Butt, J.W. Richardson, J.U. Li, Thermal expansion and atomic vibrations of zirconium carbide to 1600 k, Philos. Mag. 87 (2007) 2507–2519. [2] D. Sciti, S. Guicciardi, M. Nygren, Spark plasma sintering and mechanical behaviour of ZrC-based composites, Scr. Mater. 59 (2008) 638–641. [3] X. Ren, Z. Peng, C. Wang, Z. Fu, L. Qi, H. Miao, Effect of ZrC nano-powder addition on the microstructure and mechanical properties of binderless tungsten carbide fabricated by spark plasma sintering, Int J Refract Met H 48 (2015) 398–407. [4] A. Chu, M. Qin, R.-U. Din, L. Zhang, H. Lu, B. Jia, X. Qu, Carbothermal synthesis of ZrC powders using a combustion synthesis precursor, Int. J. Refract. Met. Hard Mater. 36 (2013) 204–210. [5] C. Yan, R. Liu, Y. Cao, C. Zhang, D. Zhang, Synthesis of submicrometer zirconium carbide formed from inorganic–organic hybrid precursor pyrolysis, J. Sol-Gel Sci. Technol. 64 (2012) 251–256. [6] T. Tsuchida, M. Kawaguchi, K. Kodaira, Synthesis of ZrC and ZrN in air from mechanically activated ZrC powder mixtures, Solid State Ionics 101 (1997) 149–154. [7] J. Dong, W.C. Shen, X.F. Hu, B.F. Zhang, X. Liu, F.Y. Kang, J.L. Gu, N.P. Chen, A kind of carbon whiskers in new structure and morphology, Sci. China B 44 (2001) 55–62. [8] C. Yan, R. Liu, Y. Cao, C. Zhang, D. Zhang, Carbothermal synthesis of submicrometer zirconium carbide from polyzirconoxane and phenolic resin by the facile one-pot reaction, J. Am. Ceram. Soc. 95 (2012) 3366–3369.
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[9] X. Tao, W. Qiu, H. Li, T. Zhao, Synthesis of nanosized zirconium carbide from preceramic polymers by the facile one-pot reaction, Polym. Adv. Technol. 21 (2010) 300–304. [10] L. Wang, L. Si, Y. Zhu, Y. Qian, Solid-state reaction synthesis of ZrC from zirconium oxide at low temperature, Int. J. Refract. Met. Hard Mater. 38 (2013) 134–136. [11] C.H. Xu, L. Zhe, R. Yang, Z.L. Wang, Synthesis of single-crystalline niobate nanorods via ion-exchange based on molten-salt reaction, J. Am. Chem. Soc. 129 (2007) 15444–15445.
[12] X. Tao, X. Wei, Q. Chen, W. Lu, M. Ma, T. Zhao, Synthesis, characterization and thermal behavior of new preceramic polymers for zirconium carbide, Adv. Appl. Ceram. 112 (2013) 301–305. [13] A. Abdel Aal, S.M. El-Sheikh, Y.M.Z. Ahmed, Electrodeposited composite coating of Ni–W–P with nano-sized rod-and spherical-shaped SiC particles, Mater. Res. Bull. 44 (2009) 151–159. [14] L.F. Benea, F. Wenger, P. Ponthiaux, J.P. Celis, Tribocorrosion behavior of Ni–SiC nano-structured composite coatings obtained by electrodeposition, Wear 266 (2009) 398–405.
Contents lists available at ScienceDirect
Int. Journal of Refractory Metals and Hard Materials journal homepage: www.elsevier.com/locate/IJRMHM
Synthesis and characterization of zirconium carbide nanorods at low temperature Mohammad Mahdavi a,⁎, Mazaher Ramazani b, Zahra Darvishi a a b
Department of Chemistry, Malek-ashtar University of Technology, Shahin-shahr, P.O. Box 83145/115, Islamic Republic of Iran Department of Materials Engineering, Malek-ashtar University of Technology, Islamic Republic of Iran
a r t i c l e
i n f o
Article history: Received 21 September 2015 Received in revised form 9 November 2015 Accepted 18 November 2015 Available online 18 December 2015 Keywords: Zirconium carbide Nanorod Low temperature Nanoparticles Ceramics
a b s t r a c t A novel chemical synthetic method at low temperature was developed for the synthesis of ZrC nanorods, using ZrCl4 and sodium metal in the presence of naphthalene as the carbon source. The results showed that the ZrCl4, after heat treatment in argon atmosphere at temperatures above 500°C, can be completely converted into ZrC nanorods. However, the initial formation temperature of ZrC was as low as 400 °C whereas ZrO2 as an intermediate product was also produced from the precursor at 300°C, and the mixture was finally transformed into pure ZrC at 700°C. The synthesized ZrC nanorods exhibited cubic lattice structure. © 2015 Elsevier Ltd. All rights reserved.
1. Introduction ZrC is one of the large families of highly refractory interstitial compounds with the NaCl-type structure [1]. ZrC has attracted considerable interest due to its various unique properties, such as high hardness, high melting point, high chemical stability and high resistance to radiation, which makes it suitable for many applications, such as field emitters, coating of nuclear fuels and cutting tools [2,3]. Several different synthetic methods have been developed for the synthesis of ZrC, such as carbothermic reduction of ZrO2 at elevated temperatures [4], solutionbased processing at low temperature [5], mechanochemical reaction of Zr and C [6,7], solid state metathesis route [8], preceramic polymer method [9], Mg-thermite method [10] and co-reduction method [11,12]. Metal carbide nanorods play a noteworthy role in leading scientific and industrial research of nanotechnology [13]. Nowadays these nanorods are being studied widely, due to their improved mechanical and physical properties [14]. In the present work, for the first time we develop a simple method to prepare ZrC nanorods at low-temperature using ZrCl4 and naphthalene as carbon source material.
condensation into toluene under argon atmosphere. The crystal structure and phase identity of ZrC nanorods were determined by X-ray diffraction (XRD) using a Bruker D8 ADVANCE instrument. Field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis (EDAX) studies were done on SEM Philips XL30. 2.1. Preparation of ZrC All the reactions were carried out under argon atmosphere. In a typical experimental procedure, appropriate amounts of ZrCl4 (4.82 g) and naphthalene (2.23-g) were dissolved in minimum volume of toluene in a steel reactor. The reagents were stirred at 100 °C after that slightly excessive of Na (1.95 g) was added into the solution and stirring was continued to evaporate toluene until a brown solid remained. The brown solid was heated in an electric furnace at various temperatures (200, 300, 400, 500, 600 and 700 °C) under argon atmosphere for 1 h and then cooled to room temperature. The products were crushed and washed several times with distilled water to remove NaCl, until a silver nitrate test showed that chlorine was completely eliminated. The product was dried in vacuum at 200 °C for 30 min.
2. Materials and methods
3. Results and discussion
Chemicals including sodium metal (99.7%) and naphthalene (99.98%) were used as received. ZrCl4 (98%) was purified by sublimation and
The phase identity and phase mixture of the products obtained at various temperatures were characterized by XRD analysis (Fig. 1). After heat treatment at 300 °C, the product of the reaction was mainly t-ZrO2 (tetragonal ZrO2). When the heat treatment temperature increased to 400 °C, both m-ZrO2 (monoclinic ZrO2) and t-ZrO2 were
⁎ Corresponding author. E-mail address: [email protected] (M. Mahdavi).
http://dx.doi.org/10.1016/j.ijrmhm.2015.11.015 0263-4368/© 2015 Elsevier Ltd. All rights reserved.
60
M. Mahdavi et al. / Int. Journal of Refractory Metals and Hard Materials 56 (2016) 59–62
Fig. 1. XRD patterns of ZrCl4–naphthalene reactions at different temperatures.
detected, indicating that some t-ZrO2 had transformed to m-ZrO2. Meanwhile, the initial formation of ZrC was observed at 400 °C. There were no diffraction peaks of graphite in the patterns. At temperatures above 400 °C, all t-ZrO2 had transformed to m-ZrO2, and the intensity of ZrC peaks was increased. At 700 °C, m-ZrO2 phase disappeared completely and ZrC was the only crystalline phase. The XRD pattern exhibited characteristic peaks at 2θ 33.1°, 38.4°, 55.4°, 65.9° and 69.3°, which conformed the formation of ZrC to cubic lattice structure.
Fig. 2 shows FE-SEM micrographs of ZrC nanorods, synthesized at 700 °C. The average diameter sizes of nanocrystallites were different but they had high aspect ratios. The ZrC nanorods were substantially straight and the same along the length of the nanorods. It seems that in addition to carbon source, naphthalene facilitate the reaction through a dissolution process of sodium metal and formation of sodium naphthalenide (Na+ C10H− 8 ). This active intermediate reacts well with ZrCl4 vapor along the ZrC nanorods.
Fig. 2. FE-SEM micrographs of ZrC nanorods.
Fig. 3. XRD pattern of Zr–carbon reaction at 700 °C.
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Fig. 4. FE-SEM micrographs of Zr nanoparticles.
Fig. 5. EDAX analysis of zirconium metal.
To investigate the role of the carbon source, the graphite powder was used as a carbon source instead of naphthalene, for the production of zirconium carbide at various temperatures (200, 300, 400, 500, 600 and 700 °C) under argon atmosphere for 1 h. In this new condition the product was zirconium powder. The phase identity and phase mixture of the product obtained at 700 °C were merely Zr metal based on the XRD analysis (Fig. 3). The FE-SEM micrographs show the morphology and particle size of zirconium nanoparticles with sizes between 50 and 70 nm (Fig. 4). The EDAX analysis was performed to further confirm the phase identity of the product obtained of the as-prepared Zr powder (Fig. 5). The spectrum shows that the sample contains Zr, after washing with distilled water and drying. 4. Conclusions In summary, we succeeded in synthesizing ZrC through the reduction of ZrCl4 and naphthalene with sodium metal at low temperatures. An in situ template reduction-carbonization mechanism is proposed for creation of ZrC nanorods. It is believed that such a method could be extended to fabricate similar nanostructures for other important carbides such as TiC and SiC. These materials suggest exciting opportunities for both essential research and technological applications. Low-temperature synthesis of ZrC has many advantages including the controllable crystalline size, and chemical composition of the final product. The method provides zirconium carbide nanorods on a large scale, and is easy to scale up due to the inexpensive and unlimited availability of reagents.
The small diameter and high aspect ratio of the ZrC nanorods also make them useful as improved reinforcements in metals, ceramics, and polymer matrix composites. The ZrC nanorods can be used in particular products such as cutting tools, engineering composites including gas turbine blades, high strength ceramics, and unique building blocks for new nanomaterials with interesting physical properties. The ZrC nanorods can be used as abrasives or in wear resistant surfaces. These nanorods can also be used as new probe tips for atomic force microscopy (AFM) or biology. References [1] A.C. Lawson, D.P. Butt, J.W. Richardson, J.U. Li, Thermal expansion and atomic vibrations of zirconium carbide to 1600 k, Philos. Mag. 87 (2007) 2507–2519. [2] D. Sciti, S. Guicciardi, M. Nygren, Spark plasma sintering and mechanical behaviour of ZrC-based composites, Scr. Mater. 59 (2008) 638–641. [3] X. Ren, Z. Peng, C. Wang, Z. Fu, L. Qi, H. Miao, Effect of ZrC nano-powder addition on the microstructure and mechanical properties of binderless tungsten carbide fabricated by spark plasma sintering, Int J Refract Met H 48 (2015) 398–407. [4] A. Chu, M. Qin, R.-U. Din, L. Zhang, H. Lu, B. Jia, X. Qu, Carbothermal synthesis of ZrC powders using a combustion synthesis precursor, Int. J. Refract. Met. Hard Mater. 36 (2013) 204–210. [5] C. Yan, R. Liu, Y. Cao, C. Zhang, D. Zhang, Synthesis of submicrometer zirconium carbide formed from inorganic–organic hybrid precursor pyrolysis, J. Sol-Gel Sci. Technol. 64 (2012) 251–256. [6] T. Tsuchida, M. Kawaguchi, K. Kodaira, Synthesis of ZrC and ZrN in air from mechanically activated ZrC powder mixtures, Solid State Ionics 101 (1997) 149–154. [7] J. Dong, W.C. Shen, X.F. Hu, B.F. Zhang, X. Liu, F.Y. Kang, J.L. Gu, N.P. Chen, A kind of carbon whiskers in new structure and morphology, Sci. China B 44 (2001) 55–62. [8] C. Yan, R. Liu, Y. Cao, C. Zhang, D. Zhang, Carbothermal synthesis of submicrometer zirconium carbide from polyzirconoxane and phenolic resin by the facile one-pot reaction, J. Am. Ceram. Soc. 95 (2012) 3366–3369.
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M. Mahdavi et al. / Int. Journal of Refractory Metals and Hard Materials 56 (2016) 59–62
[9] X. Tao, W. Qiu, H. Li, T. Zhao, Synthesis of nanosized zirconium carbide from preceramic polymers by the facile one-pot reaction, Polym. Adv. Technol. 21 (2010) 300–304. [10] L. Wang, L. Si, Y. Zhu, Y. Qian, Solid-state reaction synthesis of ZrC from zirconium oxide at low temperature, Int. J. Refract. Met. Hard Mater. 38 (2013) 134–136. [11] C.H. Xu, L. Zhe, R. Yang, Z.L. Wang, Synthesis of single-crystalline niobate nanorods via ion-exchange based on molten-salt reaction, J. Am. Chem. Soc. 129 (2007) 15444–15445.
[12] X. Tao, X. Wei, Q. Chen, W. Lu, M. Ma, T. Zhao, Synthesis, characterization and thermal behavior of new preceramic polymers for zirconium carbide, Adv. Appl. Ceram. 112 (2013) 301–305. [13] A. Abdel Aal, S.M. El-Sheikh, Y.M.Z. Ahmed, Electrodeposited composite coating of Ni–W–P with nano-sized rod-and spherical-shaped SiC particles, Mater. Res. Bull. 44 (2009) 151–159. [14] L.F. Benea, F. Wenger, P. Ponthiaux, J.P. Celis, Tribocorrosion behavior of Ni–SiC nano-structured composite coatings obtained by electrodeposition, Wear 266 (2009) 398–405.