- Email: [email protected]
Synthesis of cobalt oxide nanowires using a glycerol thermal route
Materials Letters 96 (2013) 60–62
Contents lists available at SciVerse ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
Synthesis of cobalt oxide nanowires using a glycerol thermal route Kushal D. Bhatte, Bhalchandra M. Bhanage n Department of Chemistry, Institute of Chemical Technology, Matunga, Mumbai 400019, India
a r t i c l e i n f o
a b s t r a c t
Article history: Received 13 October 2012 Accepted 8 January 2013 Available online 17 January 2013
A one step, convenient method for the preparation of cobalt oxide (Co3O4) nanowires using a glycerol thermal route has been developed. In present methodology formation of nanocrystalline materials was carried out using glycerol as a solvent and cobalt nitrate as a precursor. In this protocol, glycerol is a versatile solvent and eliminated use of any other extraneous reagents such as base, capping agents, fuel and template. The characterisation of synthesised nanosize cobalt oxide was carried out using XRD, TEM and EDAX analysis. The TEM analysis showed that the morphology of prepared nanosize cobalt oxide is of nanowire. The XRD and EDAX spectral analysis revealed the quality and purity of nanosize zinc oxide. This is one of simple and environment friendly route for the synthesis of nanosize Co3O4. & 2013 Elsevier B.V. All rights reserved.
Keywords: Nanoparticles Glyecrol Co3O4 Nanocrystalline material
1. Introduction Nanosize metal and metal oxide synthesis have gained a considerable attention in different disciplines of sciences such as chemistry, medicinal study, material science and physics owing to their intrinsic different fundamental properties as compared to bulk materials [1]. Among different nanosize metal oxide, nanosize cobalt oxide (Co3O4) has attracted a lot of attention due to its properties and numerous applications in various fields. Nanosize Co3O4 is an important magnetic p-type semiconductor material [2]. It also finds applications in catalysis, lithium ion batteries, magnetic materials, electro-chromic devices, pH sensors, gas sensors, magnetic devices, electrochemical system, electronic devices, and high temperature solar cell devices [3–11]. There are mammoth reports available on the preparation of nanosize Co3O4 using different ways like chemical vapour deposition, ball milling, pulsed-laser deposition, precipitation technique, and sol–gel process [12–16]. However such protocols possess many disadvantages like use of high calcination temperature and toxic reagents, long reaction time, low quantity of product, multistep synthesis and requirement of external additives during the reaction which limits its purity. Hence there is enough room for the development of facile, convenient and additive free synthesis of nanosize Co3O4 which can provide both qualitative and quantitative support for its commercial applications. The above drawbacks can be diminished in solvo-thermal especially using alcohol or polyol as a solvent. Nowadays, the synthesis of nanosize material via alcohol or polyol assisted routes has come into more focus in material chemistry [17–24]. Solvothermal process has been proven to be a
n
Corresponding author. Tel.: þ91 22 3361 1111x2222; fax: þ 91 22 3361 1020. E-mail addresses: [email protected], [email protected] (B.M. Bhanage). 0167-577X/$ - see front matter & 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.matlet.2013.01.019
powerful tool for synthesising novel materials with interesting properties [23]. It offers the synthetic route that allows the economical synthesis of nanosized materials at mild conditions [23]. In the polyol process, the polyol serves multiple functions as a solvent, stabiliser and reducing agent. Polyol limits particle growth and prevents agglomeration [21]. Glycerol is a colourless, odourless, relatively safe, inexpensive, viscous, easily available and hydroscopic polyol that has immense applications in food and pharmaceutical industry and its application in synthesis of nanosize metal oxide has not been explored [25]. Herein we proposed a facile, economical and additive free glycerol thermal synthesis of nanocrystalline Co3O4 using glycerol and cobalt nitrate only. The developed protocol is simple, economical and convenient as it works without any further additive than glycerol and produce nanosize cobalt oxide at relatively low temperature.
2. Experimental The Co(NO3)2 6H2O and glycerol of A.R. grade were purchased from Spectrochem Chemicals Pvt. Ltd. India and used without further purification. The synthesis of nanosize Co3O4 was carried out in 100 ml Teflon lined stainless steel autoclave (M/S Amar autoclave Ltd., India). In a typical procedure, the mixture of 3 g of cobalt nitrate in 20 ml glycerol was transferred to the autoclave. The reaction was carried out at 150 1C for 3 h and kept under autogenously developed pressure. After the reaction, the autoclave was cooled to room temperature naturally, the red brown, corrosive gas evolved upon autoclave openings. The product was obtained without subsequent thermal treatment recovered by diluting reaction mixture by small aliquots of ethanol: water (1:1 by volume) followed by high speed centrifugation. The product was washed
K.D. Bhatte, B.M. Bhanage / Materials Letters 96 (2013) 60–62
61
micrograph (Fig. 1) witnesses that the obtained cobalt oxide samples are nanograined and contain the very developed free surfaces as well as grain boundaries. It has been demonstrated recently by Straumal et al. [29] that the physical properties of nanograined oxides, especially doped one, strongly depend on the presence of defects like grain boundaries and on the presence of (invisible for XRD) amorphous surficial and intergranular layers [30]. The nontrivial behaviour of cobalt oxide samples can be driven by the properties of free surfaces and grain boundaries in cobalt oxide. 3.2. Formation of nanosize cobalt oxide
Fig. 1. TEM image of nanosize Co3O4 with SAED pattern.
Fig. 2. XRD image of nanosize Co3O4.
In present protocol temperature required for the formation of nanosize Co3O4 is noticeably lower than that earlier reported via thermal calcination [2]. It proves that glycerol played a vital role in the formation of nanosize Co3O4. The formation of nanosize Co3O4 in this protocol involves few simultaneous steps. It can be noted that present reaction can be considered as the glycerol assisted thermal combustion of cobalt nitrate to cobalt oxide wherein glycerol acts a solvent and fuel. It has been reported previously that formation of nanosize metal oxide in polyol takes place via hydrolysis reaction of water in the metal salt with polyol [21,26,27]. It results in the formation of NO2, which further converted to nitric acid due to water. This redox reaction being exothermic in nature resulted in combustion process and it triggers the formation of metal oxide [26–28]. The formation of nanosize Co3O4 in glycerol is resulted due to above mentioned sequential redox reaction which is exothermic in nature. We observed red brown gas NO2 gas upon autoclave opening which indicates the formation of nanosize Co3O4 takes place by proposed mechanism.
4. Conclusion
Fig. 3. EDAX image of nanosize Co3O4.
several times with distilled water and ethanol and then vacuum dried at room temperature. A black coloured product was obtained. The obtained Co3O4 was characterised by X-ray diffraction ˚ transmission (XRD) (miniflex Rigaku model using CuKa ¼1.54 A), electron microscopy (TEM) (Philips CM-200, operating at 120 kV) and elemental detection spectroscopy analysis (EDAX) (JEOL-JFC 1600) with gold coating.
The present protocol represents a simple, economic, convenient and eco-friendly method for the synthesis of nanowire shape cobalt oxide through glycerol thermal method. We are expecting this simple protocol will have an impact on nanomaterials synthesis via a solvo-thermal route and it will extend for synthesis of other materials in future as well.
Acknowledgement The authors express their gratitude towards Department of Science and Technology, Govt. of India for DST-Nanomission Project SR/NM/NS-1097/2011 for financial assistance.
3. Results and discussion 3.1. Analysis of nanosize cobalt oxide The TEM image (Fig. 1) shows that product Co3O4 formed is in nanoregion with uniform nanowire shape. The SAED pattern inside the TEM image (Fig. 1) indicates the crystalline nature of product formed. Fig. 2 shows X-ray diffraction pattern of the planes (220), (400), (311), (422) and (511) are well index for cubic cobalt oxide. These results are in well agreement with JCPDS card no. 42-1467. The EDAX spectrum of Co3O4 (Fig. 3) showed peaks correspond to of cobalt and oxygen elements only. The element wt% for Co and O were found to be 73and 27 respectively, which are in close agreement with theoretical calculations for wt% of Co and O in Co3O4. The absence of any peak for Co metal, starting precursor and other phase oxide in XRD and presence of only cobalt and oxygen elemental peaks in EDAX analysis confirm the high purity of formed Co3O4. In particular, cobalt oxide is also a promising material for spintronics since it can possess the ferromagnetic properties. The
References [1] Hu JT, Odom TW, Leiber CM. Acc Chem Res 1999;32:435–45. [2] Sinko K, Szabo G, Zrı´nyi M. J Nanosci Nanotech 2011;11:1–9. [3] Cheng CS, Serizawa M, Sakata H, Hirayama T. Mater Chem Phys 1998;53:225–9. [4] Ando M, Kobayashi T, Iijima S, Haruta M. J Mater Chem 1997;7:1779–82. [5] Maruyama T, Arai S. J Electrochem Soc 1996;143:1383–7. [6] Wang GX, Chen Y, Konstantinov K, Yao J, Ash JH, Liu HK, et al. J Alloys Compd 2002;L5:340-5. [7] Smith GB, Ignatiev A, Zajac G. J Appl Phys 1980;51:4186–96. [8] Bhatte KD, Sawant BM, Deshmukh KM, Bhanage BM. Catal Commun 2011;16:114–9. [9] Fornasari G, Gusi S, Trifiro F, Vaccari A. Ind Eng Chem Res 1987;26:1500–8. [10] Natile MM, Glisenti A. Chem Mater 2002;14:3090–7. [11] Fierro G, Ferraris G, Dragone R, MLo Jacono, Faticanti M. Catal Today 2006;116:38–42. [12] Garavaglia R, Mari CM, Trasatti S. Surf Technol 1983;19:197–201. [13] Yang H, Hu Y, Zhang X, Qiu G. Mater Lett 2004;58:387–9. [14] Zeng HC, Lim YY. J Mater Res 2000;15:1250–4. [15] Koshizaki N, Narazaki A, Sasaki T. Scr Mater 2001;44:1925–9. [16] Vegl FS, Orel B, Grabec I, Kauc V. Electrochim Acta 2000;45:4359–62.
62
K.D. Bhatte, B.M. Bhanage / Materials Letters 96 (2013) 60–62
[17] Bhatte KD, Tambade PJ, Arai M, Fujita S, Bhanage BM. Powder Technol 2010;203:415–8. [18] Bhatte KD, Watile R, Sawant DN, Bhanage BM. Mater Lett 2012;69:66–8. [19] Bhatte KD, Pandit A, Arai M, Fujita S, Bhanage BM. Ultra Sonochem 2011;18:54–8. [20] Bhatte KD, Sawant DN, Deshmukh KM, Bhanage BM. Particuology 2012;10:384–7. [21] Orel ZC, lovar AA, Drazic G, Zyigon M. Cryst Growth Des 2007;7:453–8. [22] Jiang X, Wang Y, Herrick T, Xia YJ. J Mater Chem 2004;14:695–700. [23] Hong ZS, Cao Y, Deng J. Mater Lett 2002;52:34–8.
[24] Ma X, Jiang T, Hang B, Zhang J, Miao S, Ding K, et al. Catal Commun 2008;9:70–4. [25] Gu Y, Jerome F. Green Chem 2010;12:1127–38. [26] Nguyen MH, Lee SJ, Kriven WM. J Mater Res 1999;14:3417–26. [27] Chandramouli V, Anthonysamy S, Rao PR, Divakar R, Sundararaman D. J Nucl Mater 1996;231:213–8. [28] Gulgun MA, Nguyen MH, Kriven WM. J Am Ceram Soc 1999;82:556–60. [29] Straumal BB, Protasova SG, Mazilkin AA, Baretzky B, Myatiev AA, Straumal PB, et al. Thin Solid Films 2011;520:1192–4. [30] Straumal BB, Protasova SG, Mazilkin AA, Baretzky B, Myatiev AA, Straumal PB, et al. Mater Lett 2012;71:21–4.
Contents lists available at SciVerse ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
Synthesis of cobalt oxide nanowires using a glycerol thermal route Kushal D. Bhatte, Bhalchandra M. Bhanage n Department of Chemistry, Institute of Chemical Technology, Matunga, Mumbai 400019, India
a r t i c l e i n f o
a b s t r a c t
Article history: Received 13 October 2012 Accepted 8 January 2013 Available online 17 January 2013
A one step, convenient method for the preparation of cobalt oxide (Co3O4) nanowires using a glycerol thermal route has been developed. In present methodology formation of nanocrystalline materials was carried out using glycerol as a solvent and cobalt nitrate as a precursor. In this protocol, glycerol is a versatile solvent and eliminated use of any other extraneous reagents such as base, capping agents, fuel and template. The characterisation of synthesised nanosize cobalt oxide was carried out using XRD, TEM and EDAX analysis. The TEM analysis showed that the morphology of prepared nanosize cobalt oxide is of nanowire. The XRD and EDAX spectral analysis revealed the quality and purity of nanosize zinc oxide. This is one of simple and environment friendly route for the synthesis of nanosize Co3O4. & 2013 Elsevier B.V. All rights reserved.
Keywords: Nanoparticles Glyecrol Co3O4 Nanocrystalline material
1. Introduction Nanosize metal and metal oxide synthesis have gained a considerable attention in different disciplines of sciences such as chemistry, medicinal study, material science and physics owing to their intrinsic different fundamental properties as compared to bulk materials [1]. Among different nanosize metal oxide, nanosize cobalt oxide (Co3O4) has attracted a lot of attention due to its properties and numerous applications in various fields. Nanosize Co3O4 is an important magnetic p-type semiconductor material [2]. It also finds applications in catalysis, lithium ion batteries, magnetic materials, electro-chromic devices, pH sensors, gas sensors, magnetic devices, electrochemical system, electronic devices, and high temperature solar cell devices [3–11]. There are mammoth reports available on the preparation of nanosize Co3O4 using different ways like chemical vapour deposition, ball milling, pulsed-laser deposition, precipitation technique, and sol–gel process [12–16]. However such protocols possess many disadvantages like use of high calcination temperature and toxic reagents, long reaction time, low quantity of product, multistep synthesis and requirement of external additives during the reaction which limits its purity. Hence there is enough room for the development of facile, convenient and additive free synthesis of nanosize Co3O4 which can provide both qualitative and quantitative support for its commercial applications. The above drawbacks can be diminished in solvo-thermal especially using alcohol or polyol as a solvent. Nowadays, the synthesis of nanosize material via alcohol or polyol assisted routes has come into more focus in material chemistry [17–24]. Solvothermal process has been proven to be a
n
Corresponding author. Tel.: þ91 22 3361 1111x2222; fax: þ 91 22 3361 1020. E-mail addresses: [email protected], [email protected] (B.M. Bhanage). 0167-577X/$ - see front matter & 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.matlet.2013.01.019
powerful tool for synthesising novel materials with interesting properties [23]. It offers the synthetic route that allows the economical synthesis of nanosized materials at mild conditions [23]. In the polyol process, the polyol serves multiple functions as a solvent, stabiliser and reducing agent. Polyol limits particle growth and prevents agglomeration [21]. Glycerol is a colourless, odourless, relatively safe, inexpensive, viscous, easily available and hydroscopic polyol that has immense applications in food and pharmaceutical industry and its application in synthesis of nanosize metal oxide has not been explored [25]. Herein we proposed a facile, economical and additive free glycerol thermal synthesis of nanocrystalline Co3O4 using glycerol and cobalt nitrate only. The developed protocol is simple, economical and convenient as it works without any further additive than glycerol and produce nanosize cobalt oxide at relatively low temperature.
2. Experimental The Co(NO3)2 6H2O and glycerol of A.R. grade were purchased from Spectrochem Chemicals Pvt. Ltd. India and used without further purification. The synthesis of nanosize Co3O4 was carried out in 100 ml Teflon lined stainless steel autoclave (M/S Amar autoclave Ltd., India). In a typical procedure, the mixture of 3 g of cobalt nitrate in 20 ml glycerol was transferred to the autoclave. The reaction was carried out at 150 1C for 3 h and kept under autogenously developed pressure. After the reaction, the autoclave was cooled to room temperature naturally, the red brown, corrosive gas evolved upon autoclave openings. The product was obtained without subsequent thermal treatment recovered by diluting reaction mixture by small aliquots of ethanol: water (1:1 by volume) followed by high speed centrifugation. The product was washed
K.D. Bhatte, B.M. Bhanage / Materials Letters 96 (2013) 60–62
61
micrograph (Fig. 1) witnesses that the obtained cobalt oxide samples are nanograined and contain the very developed free surfaces as well as grain boundaries. It has been demonstrated recently by Straumal et al. [29] that the physical properties of nanograined oxides, especially doped one, strongly depend on the presence of defects like grain boundaries and on the presence of (invisible for XRD) amorphous surficial and intergranular layers [30]. The nontrivial behaviour of cobalt oxide samples can be driven by the properties of free surfaces and grain boundaries in cobalt oxide. 3.2. Formation of nanosize cobalt oxide
Fig. 1. TEM image of nanosize Co3O4 with SAED pattern.
Fig. 2. XRD image of nanosize Co3O4.
In present protocol temperature required for the formation of nanosize Co3O4 is noticeably lower than that earlier reported via thermal calcination [2]. It proves that glycerol played a vital role in the formation of nanosize Co3O4. The formation of nanosize Co3O4 in this protocol involves few simultaneous steps. It can be noted that present reaction can be considered as the glycerol assisted thermal combustion of cobalt nitrate to cobalt oxide wherein glycerol acts a solvent and fuel. It has been reported previously that formation of nanosize metal oxide in polyol takes place via hydrolysis reaction of water in the metal salt with polyol [21,26,27]. It results in the formation of NO2, which further converted to nitric acid due to water. This redox reaction being exothermic in nature resulted in combustion process and it triggers the formation of metal oxide [26–28]. The formation of nanosize Co3O4 in glycerol is resulted due to above mentioned sequential redox reaction which is exothermic in nature. We observed red brown gas NO2 gas upon autoclave opening which indicates the formation of nanosize Co3O4 takes place by proposed mechanism.
4. Conclusion
Fig. 3. EDAX image of nanosize Co3O4.
several times with distilled water and ethanol and then vacuum dried at room temperature. A black coloured product was obtained. The obtained Co3O4 was characterised by X-ray diffraction ˚ transmission (XRD) (miniflex Rigaku model using CuKa ¼1.54 A), electron microscopy (TEM) (Philips CM-200, operating at 120 kV) and elemental detection spectroscopy analysis (EDAX) (JEOL-JFC 1600) with gold coating.
The present protocol represents a simple, economic, convenient and eco-friendly method for the synthesis of nanowire shape cobalt oxide through glycerol thermal method. We are expecting this simple protocol will have an impact on nanomaterials synthesis via a solvo-thermal route and it will extend for synthesis of other materials in future as well.
Acknowledgement The authors express their gratitude towards Department of Science and Technology, Govt. of India for DST-Nanomission Project SR/NM/NS-1097/2011 for financial assistance.
3. Results and discussion 3.1. Analysis of nanosize cobalt oxide The TEM image (Fig. 1) shows that product Co3O4 formed is in nanoregion with uniform nanowire shape. The SAED pattern inside the TEM image (Fig. 1) indicates the crystalline nature of product formed. Fig. 2 shows X-ray diffraction pattern of the planes (220), (400), (311), (422) and (511) are well index for cubic cobalt oxide. These results are in well agreement with JCPDS card no. 42-1467. The EDAX spectrum of Co3O4 (Fig. 3) showed peaks correspond to of cobalt and oxygen elements only. The element wt% for Co and O were found to be 73and 27 respectively, which are in close agreement with theoretical calculations for wt% of Co and O in Co3O4. The absence of any peak for Co metal, starting precursor and other phase oxide in XRD and presence of only cobalt and oxygen elemental peaks in EDAX analysis confirm the high purity of formed Co3O4. In particular, cobalt oxide is also a promising material for spintronics since it can possess the ferromagnetic properties. The
References [1] Hu JT, Odom TW, Leiber CM. Acc Chem Res 1999;32:435–45. [2] Sinko K, Szabo G, Zrı´nyi M. J Nanosci Nanotech 2011;11:1–9. [3] Cheng CS, Serizawa M, Sakata H, Hirayama T. Mater Chem Phys 1998;53:225–9. [4] Ando M, Kobayashi T, Iijima S, Haruta M. J Mater Chem 1997;7:1779–82. [5] Maruyama T, Arai S. J Electrochem Soc 1996;143:1383–7. [6] Wang GX, Chen Y, Konstantinov K, Yao J, Ash JH, Liu HK, et al. J Alloys Compd 2002;L5:340-5. [7] Smith GB, Ignatiev A, Zajac G. J Appl Phys 1980;51:4186–96. [8] Bhatte KD, Sawant BM, Deshmukh KM, Bhanage BM. Catal Commun 2011;16:114–9. [9] Fornasari G, Gusi S, Trifiro F, Vaccari A. Ind Eng Chem Res 1987;26:1500–8. [10] Natile MM, Glisenti A. Chem Mater 2002;14:3090–7. [11] Fierro G, Ferraris G, Dragone R, MLo Jacono, Faticanti M. Catal Today 2006;116:38–42. [12] Garavaglia R, Mari CM, Trasatti S. Surf Technol 1983;19:197–201. [13] Yang H, Hu Y, Zhang X, Qiu G. Mater Lett 2004;58:387–9. [14] Zeng HC, Lim YY. J Mater Res 2000;15:1250–4. [15] Koshizaki N, Narazaki A, Sasaki T. Scr Mater 2001;44:1925–9. [16] Vegl FS, Orel B, Grabec I, Kauc V. Electrochim Acta 2000;45:4359–62.
62
K.D. Bhatte, B.M. Bhanage / Materials Letters 96 (2013) 60–62
[17] Bhatte KD, Tambade PJ, Arai M, Fujita S, Bhanage BM. Powder Technol 2010;203:415–8. [18] Bhatte KD, Watile R, Sawant DN, Bhanage BM. Mater Lett 2012;69:66–8. [19] Bhatte KD, Pandit A, Arai M, Fujita S, Bhanage BM. Ultra Sonochem 2011;18:54–8. [20] Bhatte KD, Sawant DN, Deshmukh KM, Bhanage BM. Particuology 2012;10:384–7. [21] Orel ZC, lovar AA, Drazic G, Zyigon M. Cryst Growth Des 2007;7:453–8. [22] Jiang X, Wang Y, Herrick T, Xia YJ. J Mater Chem 2004;14:695–700. [23] Hong ZS, Cao Y, Deng J. Mater Lett 2002;52:34–8.
[24] Ma X, Jiang T, Hang B, Zhang J, Miao S, Ding K, et al. Catal Commun 2008;9:70–4. [25] Gu Y, Jerome F. Green Chem 2010;12:1127–38. [26] Nguyen MH, Lee SJ, Kriven WM. J Mater Res 1999;14:3417–26. [27] Chandramouli V, Anthonysamy S, Rao PR, Divakar R, Sundararaman D. J Nucl Mater 1996;231:213–8. [28] Gulgun MA, Nguyen MH, Kriven WM. J Am Ceram Soc 1999;82:556–60. [29] Straumal BB, Protasova SG, Mazilkin AA, Baretzky B, Myatiev AA, Straumal PB, et al. Thin Solid Films 2011;520:1192–4. [30] Straumal BB, Protasova SG, Mazilkin AA, Baretzky B, Myatiev AA, Straumal PB, et al. Mater Lett 2012;71:21–4.