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Microwave-assisted synthesis of tube-like HgS nanoparticles in aqueous solution under ambient condition
Inorganic Chemistry Communications 6 (2003) 737–739 www.elsevier.com/locate/inoche
Microwave-assisted synthesis of tube-like HgS nanoparticles in aqueous solution under ambient condition Mingwang Shao, Lingfen Kong, Qing Li, Weichao Yu, Yitai Qian
*
Structure Research Laboratory and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, PR China Received 17 January 2003; accepted 7 March 2003
Abstract Tube-like HgS nanoparticles with face center cubic structure were synthesized via employing TM01 -type microwave irradiation as template. In this process, HgCl2 and Na2 S were used as mercury and sulfur sources, respectively, which changed to HgS through chemical reaction in aqueous solution and under ambient condition. The products were investigated with X-ray diffraction and transmission electron microscope. Ó 2003 Elsevier Science B.V. All rights reserved. Keywords: Nanomaterials; HgS; Microwave
As nanocrystallitesÕ physical and chemical properties depend greatly on their shape, the control of nanocrystallite morphology is important in various application, such as catalyst, solar cells, light-emitting diodes [1]. Various methods have been used to prepare different shape of nanocrystallites, such as electric arc, donor– acceptor interaction, template-supported method, sol– gel procedure, surfactant-assisted, hydrothermal and so on [2–6]. Mercury sulfide is technologically interesting material in quantum electronics [7]. It has application in the field of infrared sense because of its narrow gap band [8]. Because microwave irradiation is easy to be operated, we therefore explored its function to prepare tube-like HgS nanoparticles in aqueous solution under ambient condition. As to our knowledge, there is no report about the synthesis of tube-like HgS nanoparticles. The procedure for the preparation is as follows: 10 ml of 0.2 mol/l Na2 S and 10 ml of 0.1 mol HgCl2 were permeated, respectively, through semipermeable membrances made from collodion, to 100 ml aqueous solution. Meanwhile, the solution was maintained in a circular waveguide at room temperature (25 °C) and under ambient pressure for 20 days. The waveguide was *
Corresponding author. Tel.: +86-551-3601589; fax: +86-551-3607402. E-mail address: [email protected] (Y. Qian).
made of copper with the diameter of 95 mm in crosssection, which propagated 10 W microwave (2450 MHz). Then the black products were collected, washed with distilled water and dried in vacuum at 35 °C for 4 h. The phase and the crystallographic structure of the products was characterized by X-ray diffraction (XRD), which was recorded using a Rigaku (Japan) D/Max-cA X-ray diffractometer equipped with graphite-monochromatized Cu-Ka radiation ðk ¼ 0:15418 nmÞ. A scan rate of 0:05° s1 was applied to record the pattern in the 2h range of 10–70°. The XRD pattern of HgS products, shown in Fig. 1, is basically the same as that of the HgS cubic phase. The intense peaks at 2h ¼ ca: 26.58°, 30.74°, 43.91°, 51.96°, 54.43° and 63.74° orient along the (1 1 1), (2 0 0), (2 2 0), (3 1 1), (2 2 2) and (4 0 0) directions. The lattice constant measured for the sample is a ¼ 0:58303 0:003 nm, which is in agreement with the reported value of a ¼ 0:58517 nm (JCPDS 6-261). Fig. 2(a) depicts a transmission electron microscope (TEM) image of the products which take tube-like shape. It is evident that the boundary of the wall of the tube is quite well defined. The external diameter of these tubes is in the range of 30–50 nm, while the wall thickness is in the 5–10 nm ranges. Fig. 2(b) also shows several tubes, which can be clearly judged from their exposed tips. The products also contained many small
1387-7003/03/$ - see front matter Ó 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S1387-7003(03)00098-4
738
M. Shao et al. / Inorganic Chemistry Communications 6 (2003) 737–739
Fig. 1. XRD pattern of as-prepared sample.
directions. The electron diffraction pattern indicates that [1 1 1] is the radial direction. It is difficult to record high-resolution electron microscopy images of these tube-like HgS nanoparticles, because of the high sensitivity of HgS, like that of bismuth[9], to electron beam irradiation during the examination, which is expected due to its low melting points. The formation of tubes may be well explained with microwave-templated mechanism [10]. According to this mechanism, tube-like shape TM01 -mode microwave might take the effect of a template. It supplies an ideal environment for crystals to connect their slipping planes to form tube-like morphology. As the slip deformation process of crystals is attributed to the crystalsÕ slip characteristics and the primary slip systems of face center cube (fcc) crystals are {1 1 1}, the radial direction of these nanoparticles with an fcc structure is then fixed in [1 1 1] direction. In our experiment, the size of circular guide is 95 mm in cross-section in order to obtain a relatively pure TM01 mode, which favors the formation of tubes. The membranes might play another important role in this process. To make clear this point, we did the same experiment but without the use of membranes and only obtained HgS nanoparticles because of the high reaction rate. The membranes used here were served to control the diffusion of cations and anions. They reduce the growth rate of the crystals so that the (1 1 1) planes have enough time to slip and connect themselves to form the shape of tubes. In our experiments, when 10 runs were carried out, about five of which successfully produced tube-like HgS nanoparticles with the yield of about 15%. It should be appointed that there is an excess of Na2 S in our experiment, which is employed to ensure the formation of HgS. Otherwise Hg2 Cl2 S will appear. In summary, the present investigation shows how tube-like HgS nanoparticles were formed under ambient condition via microwave-templated method. This method was easy to be maintained and controlled. It can be speculated that many kinds of tube-like nanoparticles can be made through this method.
Acknowledgements Fig. 2. (a) and (b) TEM images showing several tube-like HgS nanoparticles; and (c) selected-area electron diffraction pattern indicating that [1 1 1] is the radial direction.
irregular HgS nanoparticles, which can be seen in the Figs. 2(a) and (b). Fig. 2(c) shows that selected-area electron diffraction (SAED) pattern is characteristic of face center cubicHgS crystallite (JCPDS 6-261). The four rings in the pattern corresponds to (1 1 1), (2 2 0), (2 2 2) and (4 2 2)
This work is supported by the National Natural Science Foundation of China and the 973 National Nanometer Materials Project.
References [1] Z.A. Peng, X.G. Peng, J. Am. Chem. Soc. 123 (2001) 1389. [2] J.X. Huang, Y. Xie, B. Li, Adv. Mater. 12 (2000) 808. [3] J.H. Zhan, X.G. Yang, D.W. Wang, Adv. Mater. 12 (2000) 1348.
M. Shao et al. / Inorganic Chemistry Communications 6 (2003) 737–739 [4] W. Tremel, Angew. Chem. Int. Ed. 38 (1999) 2175. [5] C.N.R. Rao, A. Govindaraj, F. Leonard Deepak, N.A. Gunari, Appl. Phys. Lett. 78 (2001) 1853. [6] Y.Y. Peng, Z.Y. Meng, C. Zhong, J. Lu, L.Q. Xu, S.Y. Zhang, Y.T. Qian, New J. Chem. 25 (2001) 1. [7] A. Delin, T. Kluner, Phys. Rev. B 66 (2002) 351171.
739
[8] K.A. Higginson, M. Kuno, J. Bonevich, S.B. Qadri, M. Yousuf, H. Mattoussi, J. Phys. Chem. B 106 (2002) 9982. [9] Y.D. Li, J.W. Wang, Z.X. Deng, Y.Y. Wu, X.M. Sun, D.P. Yu, P.D. Yang, J. Am. Chem. Soc. 123 (2001) 9904. [10] M.W. Shao, F. Xu, Y.Y. Peng, J. Wu, Q. Li, S.Y. Zhang, Y.T. Qian, New J. Chem. 26 (2002) 1440.
Microwave-assisted synthesis of tube-like HgS nanoparticles in aqueous solution under ambient condition Mingwang Shao, Lingfen Kong, Qing Li, Weichao Yu, Yitai Qian
*
Structure Research Laboratory and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, PR China Received 17 January 2003; accepted 7 March 2003
Abstract Tube-like HgS nanoparticles with face center cubic structure were synthesized via employing TM01 -type microwave irradiation as template. In this process, HgCl2 and Na2 S were used as mercury and sulfur sources, respectively, which changed to HgS through chemical reaction in aqueous solution and under ambient condition. The products were investigated with X-ray diffraction and transmission electron microscope. Ó 2003 Elsevier Science B.V. All rights reserved. Keywords: Nanomaterials; HgS; Microwave
As nanocrystallitesÕ physical and chemical properties depend greatly on their shape, the control of nanocrystallite morphology is important in various application, such as catalyst, solar cells, light-emitting diodes [1]. Various methods have been used to prepare different shape of nanocrystallites, such as electric arc, donor– acceptor interaction, template-supported method, sol– gel procedure, surfactant-assisted, hydrothermal and so on [2–6]. Mercury sulfide is technologically interesting material in quantum electronics [7]. It has application in the field of infrared sense because of its narrow gap band [8]. Because microwave irradiation is easy to be operated, we therefore explored its function to prepare tube-like HgS nanoparticles in aqueous solution under ambient condition. As to our knowledge, there is no report about the synthesis of tube-like HgS nanoparticles. The procedure for the preparation is as follows: 10 ml of 0.2 mol/l Na2 S and 10 ml of 0.1 mol HgCl2 were permeated, respectively, through semipermeable membrances made from collodion, to 100 ml aqueous solution. Meanwhile, the solution was maintained in a circular waveguide at room temperature (25 °C) and under ambient pressure for 20 days. The waveguide was *
Corresponding author. Tel.: +86-551-3601589; fax: +86-551-3607402. E-mail address: [email protected] (Y. Qian).
made of copper with the diameter of 95 mm in crosssection, which propagated 10 W microwave (2450 MHz). Then the black products were collected, washed with distilled water and dried in vacuum at 35 °C for 4 h. The phase and the crystallographic structure of the products was characterized by X-ray diffraction (XRD), which was recorded using a Rigaku (Japan) D/Max-cA X-ray diffractometer equipped with graphite-monochromatized Cu-Ka radiation ðk ¼ 0:15418 nmÞ. A scan rate of 0:05° s1 was applied to record the pattern in the 2h range of 10–70°. The XRD pattern of HgS products, shown in Fig. 1, is basically the same as that of the HgS cubic phase. The intense peaks at 2h ¼ ca: 26.58°, 30.74°, 43.91°, 51.96°, 54.43° and 63.74° orient along the (1 1 1), (2 0 0), (2 2 0), (3 1 1), (2 2 2) and (4 0 0) directions. The lattice constant measured for the sample is a ¼ 0:58303 0:003 nm, which is in agreement with the reported value of a ¼ 0:58517 nm (JCPDS 6-261). Fig. 2(a) depicts a transmission electron microscope (TEM) image of the products which take tube-like shape. It is evident that the boundary of the wall of the tube is quite well defined. The external diameter of these tubes is in the range of 30–50 nm, while the wall thickness is in the 5–10 nm ranges. Fig. 2(b) also shows several tubes, which can be clearly judged from their exposed tips. The products also contained many small
1387-7003/03/$ - see front matter Ó 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S1387-7003(03)00098-4
738
M. Shao et al. / Inorganic Chemistry Communications 6 (2003) 737–739
Fig. 1. XRD pattern of as-prepared sample.
directions. The electron diffraction pattern indicates that [1 1 1] is the radial direction. It is difficult to record high-resolution electron microscopy images of these tube-like HgS nanoparticles, because of the high sensitivity of HgS, like that of bismuth[9], to electron beam irradiation during the examination, which is expected due to its low melting points. The formation of tubes may be well explained with microwave-templated mechanism [10]. According to this mechanism, tube-like shape TM01 -mode microwave might take the effect of a template. It supplies an ideal environment for crystals to connect their slipping planes to form tube-like morphology. As the slip deformation process of crystals is attributed to the crystalsÕ slip characteristics and the primary slip systems of face center cube (fcc) crystals are {1 1 1}, the radial direction of these nanoparticles with an fcc structure is then fixed in [1 1 1] direction. In our experiment, the size of circular guide is 95 mm in cross-section in order to obtain a relatively pure TM01 mode, which favors the formation of tubes. The membranes might play another important role in this process. To make clear this point, we did the same experiment but without the use of membranes and only obtained HgS nanoparticles because of the high reaction rate. The membranes used here were served to control the diffusion of cations and anions. They reduce the growth rate of the crystals so that the (1 1 1) planes have enough time to slip and connect themselves to form the shape of tubes. In our experiments, when 10 runs were carried out, about five of which successfully produced tube-like HgS nanoparticles with the yield of about 15%. It should be appointed that there is an excess of Na2 S in our experiment, which is employed to ensure the formation of HgS. Otherwise Hg2 Cl2 S will appear. In summary, the present investigation shows how tube-like HgS nanoparticles were formed under ambient condition via microwave-templated method. This method was easy to be maintained and controlled. It can be speculated that many kinds of tube-like nanoparticles can be made through this method.
Acknowledgements Fig. 2. (a) and (b) TEM images showing several tube-like HgS nanoparticles; and (c) selected-area electron diffraction pattern indicating that [1 1 1] is the radial direction.
irregular HgS nanoparticles, which can be seen in the Figs. 2(a) and (b). Fig. 2(c) shows that selected-area electron diffraction (SAED) pattern is characteristic of face center cubicHgS crystallite (JCPDS 6-261). The four rings in the pattern corresponds to (1 1 1), (2 2 0), (2 2 2) and (4 2 2)
This work is supported by the National Natural Science Foundation of China and the 973 National Nanometer Materials Project.
References [1] Z.A. Peng, X.G. Peng, J. Am. Chem. Soc. 123 (2001) 1389. [2] J.X. Huang, Y. Xie, B. Li, Adv. Mater. 12 (2000) 808. [3] J.H. Zhan, X.G. Yang, D.W. Wang, Adv. Mater. 12 (2000) 1348.
M. Shao et al. / Inorganic Chemistry Communications 6 (2003) 737–739 [4] W. Tremel, Angew. Chem. Int. Ed. 38 (1999) 2175. [5] C.N.R. Rao, A. Govindaraj, F. Leonard Deepak, N.A. Gunari, Appl. Phys. Lett. 78 (2001) 1853. [6] Y.Y. Peng, Z.Y. Meng, C. Zhong, J. Lu, L.Q. Xu, S.Y. Zhang, Y.T. Qian, New J. Chem. 25 (2001) 1. [7] A. Delin, T. Kluner, Phys. Rev. B 66 (2002) 351171.
739
[8] K.A. Higginson, M. Kuno, J. Bonevich, S.B. Qadri, M. Yousuf, H. Mattoussi, J. Phys. Chem. B 106 (2002) 9982. [9] Y.D. Li, J.W. Wang, Z.X. Deng, Y.Y. Wu, X.M. Sun, D.P. Yu, P.D. Yang, J. Am. Chem. Soc. 123 (2001) 9904. [10] M.W. Shao, F. Xu, Y.Y. Peng, J. Wu, Q. Li, S.Y. Zhang, Y.T. Qian, New J. Chem. 26 (2002) 1440.