- Email: [email protected]
A facile, green, one pot synthesis of cuprous iodide nanoparticles using the mechanochemical method
Materials Letters 115 (2014) 190–193
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
A facile, green, one pot synthesis of cuprous iodide nanoparticles using the mechanochemical method Saeed Shahbazi, Shahrara Afshar n Department of Chemistry, Iran University of Science and Technology, 16846-13114 Tehran, Iran
art ic l e i nf o
a b s t r a c t
Article history: Received 10 September 2013 Accepted 5 October 2013 Available online 24 October 2013
Cuprous iodide, that recently has been used as an inorganic hole (vacant state) conductor material in dye sensitized solar cells, was successfully synthesized with a rapid, low cost, one pot and solvent free reaction using the mechanochemical method. The XRD data showed that all peaks matched well with those of the gamma phase of CuI. In addition, EDX analysis confirmed the formation of 100% pure CuI compound. Moreover, the SEM images showed the nanosized spherical morphology of 40–70 nm. The diffuse reflectance spectrum (DRS) of the product showed that CuI nanoparticles have a maximum absorption at about 400 nm and a band gap of 3 eV. The results of this contribution corroborate the successful synthesis of pure cuprous iodide (CuI) nanoparticles. & 2013 Elsevier B.V. All rights reserved.
Keywords: Cuprous iodide Green chemistry Mechanochemical method Nanoparticles Solar energy materials
1. Introduction Cuprous iodide (CuI) has many features that derived much attention during the last decade. It has large band gap, an unusually large temperature dependency and large iconicity [1,2]. This compound has also been applied as a potent catalyst for organic compound syntheses [3], ultrafast scintillators [4], and super ionic conductors, solid-state solar cells, etc. [5]. One of the main components of dye solar cells is electrolyte. Iodine-triiodide liquid electrolyte is a composition frequently used in dye solar cells [6]. However despite having a good performance as liquid electrolytes, it suffers from drawbacks such as volatility, corrosion and sealing problems that decrease the stability of the cells [7]. Hence, replacing the liquid electrolyte with solid electrolytes is one of the major challenges in producing of dye solar cells. Solid electrolytes among others have attracted much attention due to their high stability, high hole transfer speed and physical contact at the interface of a metal oxide/dye/electrolyte [7]. CuI and CuSCN are used as solid electrolytes in dye sensitized solar cells since a good overlap exists between the bands of CuI and dye [8,9]. Cuprous iodide has been prepared using several physical methods such as electrodepositing [10], pulse laser deposition [11], vacuum evaporation [12]. And different chemical methods have been reported on preparing CuI, such as the liquid phase reaction [13], low temperature solvothermal synthesis [5], coprecipitation [14], and precipitation method using capping agent and pomegranate juice [15,16]. Although the above mentioned
n
Corresponding author. Tel.: þ 98 21 7724 0288; fax: þ 98 21 7322 2705. E-mail address: [email protected] (S. Afshar).
0167-577X/$ - see front matter & 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.matlet.2013.10.072
methods may have some advantages and despite significant gains in the past, still finding a new route for green, facile and scale-up preparation of the cuprous iodide remains a challenge. In recent years, numerous scientists and technologist have paid much attention to solid state reactions because of their simplicity of application in large scale, low-cost and high efficiency. Mechanochemical processes are used to prepare different kinds of nanostructures of metal oxides [17], hydrogen storage materials [18], composites [19] and so on. Since no toxic liquid solvent have been used in these reactions, they do not pollute the environment and therefore these reactions can be considered as green chemistry methodologies. The above advantages have made the researchers to be high concerned about the mechanochemical methods compared to the other synthetic routes. In this work, for the first time, a mechanochemical method is used for the synthesis of the spherical γ-CuI nanoparticles at room temperature. This study introduces a facile, green and an easiest possible one-pot method for the synthesis of CuI compound. The proposed method has solvent-free characteristic which would result in a lower cost and being environmentally favored. In addition, the procedure of CuI synthesis is very easy in the presented work.
2. Material and method CuSO4 (99%) and KI (99.5%) were purchased from Merck Company and were used without further purification. In a stainless steel (10 mL) vial a mixture of CuSO4 and KI solids with a molar ratio of 1:2 were milled together using a Mixer Mill (Retsch MM-400) apparatus at 1800 rpm (30 Hz) for 40 min at room temperature. The brown powder as a product was expected
S. Shahbazi, S. Afshar / Materials Letters 115 (2014) 190–193
to be a mixture of cuprous iodide, molecular iodine and potassium sulfate. The mixture was washed with deionized water to remove molecular iodine and potassium sulfate salt. The precipitate was then dried in a vacuum oven at 100 1C for 2 h to obtain the final grayish white product. X-ray powder diffraction pattern (XRD) was performed on a SIEFERT XRD 3003 PTS diffractometer using Cu Kα irradiation (λ ¼1.5418 Å). Scanning electron micrographs and energy dispersive X-ray Spectroscopy were taken with a ZEISS-DSM 960A microscope with attached camera operating at 30 kV to determine the morphology, particle size and high purity of as-prepared synthesized salt. Diffuse reflectance spectrum (DRS) was measured on a TU-1901 spectrophotometer. All the measurements were done at room temperature.
3. Results and discussion Copper forms a variety of compounds with oxidation states of þ1 and þ2. In aqueous solution and for the most ligands, it is the þ2 oxidation state of the copper that dominates and is the more stable one. However, the reducing ligands, like iodide would reduce the Cu2 þ ions to the þ 1 oxidation state. Therefore, after milling the precursors, the brown powder as product was expected to be a mixture of cuprous iodide, molecular iodine and potassium sulfate. The reaction equation is as follows: 2CuSO4 þ 4KI-2CuI þ I2 þ 2K2 SO4
ð1Þ
191
In this reaction, Cu2 þ and I act as oxidizing and reducing agents, respectively. To explore the formation of the CuI and in order to identify its phase and structure X-ray diffraction pattern was used. 2θ values and their matching hkl indices are shown in Fig. 1, stating the gamma phase of CuI (JCPDS Card No. 06-0246) and indicating the formation of CuI in a cubic lattice with cell parameter (a) equal to 6.06 Å. This ratify that CuI has been formed without any impurity [15]. The particle size of the CuI powder was estimated by applying Scherrer's equation [20] and was found to be equal to 40 nm. The morphology of the obtained product was investigated by scanning electron microscopy (SEM). As can be seen in Fig. 2a and b, the SEM images show that the CuI powder is consisted of spherical nanoparticles with the size of 40–70 nm, which is very close to that obtained by XRD analysis. Also the crystallites are uniformly aggregated. The purity of the prepared CuI nanoparticles was also evidenced by the EDX pattern showed in Fig. 2c. The EDX measurement verified the existence of copper and iodide in the final product. This analysis showed a purity of 100% for the synthesized compound which is in good agreement with the XRD data. The optical absorption of the as-prepared CuI was investigated in the wavelength range of 300–800 nm. Based on the theory of optical absorption, the relation between the absorption coefficient and photon energy is as follows [20]: ahν ¼ Aðhν Eg Þ1=2
Fig. 1. (a) XRD pattern of the CuI nanoparticles; (b) the plot of (αhѵ)2 vs. hѵ and (c) optical absorption spectrum of obtained CuI nanoparticles.
ð2Þ
192
S. Shahbazi, S. Afshar / Materials Letters 115 (2014) 190–193
Fig. 2. (a,b) SEM images of CuI nanoparticles. (c) EDX pattern of synthesized product.
where here hν is the photon energy, A is a constant and Eg is the band gap. Fig. 1b and c show the plot of (ahν)2 vs. hν and the optical absorption spectrum for the as-prepared CuI nanoparticles, respectively. The size plays a significant role on the band gap of the nanoparticles and therefore on the applications that they can have. Different band gap values ranging from 2.9 to 4.2 eV are reported for the cuprous iodide in the literature. For the single crystal form of this compound, the band gap is reported to be 2.9 eV [21] and for the 20 nm particles, it is 4.77 eV [20]. In the present work the band gap for CuI was found to be 3 eV, which was obtained by extrapolation of the straight line at (ahν)2 ¼ 0. The small differences observed between the calculated band gap and the reported values in the literatures arise from agglomeration of CuI nanoparticles that can be seen in SEM images.
4. Conclusion In summary, gamma phase of CuI with the spherical morphology of particles was successfully synthesized using the mechanochemical procedure. The XRD and DRS characterizations of these nanoparticles revealed a pure gamma phase with the bang gap of about 3 eV. This facile, green and easy one-pot method for the synthesis of CuI compound is reported for the very first time. The proposed method in this work has many advantages, such as having solvent-free characteristics which result in lower costs, being environmentally favored amid a very easy procedure for the synthesis route. This glib synthesis method has a superior capability for the development and application of the solar cells in the industrial scales.
References [1] Ferhat M, Zaoui A, Certier M, Dufour JP, Khelifa B. Electronic structure of the copper halides CuCl, CuBr and CuI. Mater Sci Eng: B 1996;39:95–100. [2] Feraoun H, Aourag H, Certier M. Theoretical studies of stoichiometric CuI. Mater Chem Phys 2003;82:597–601. [3] Ziarati A, Safaei-Ghomi J, Rohani S. Pseudo five-component process for the synthesis of functionalized tricarboxamides using CuI as reusable catalyst. Chin Chem Lett 2013;24:195–8. [4] Gao P, Gu M, Liu X-L, Liu B, Huang S-M. Luminescence of CuI single crystals: On the nature of red luminescence. Appl Phys Lett 2009221904-3. [5] Liu Y, Zhan J, Zeng J, Qian Y, Tang K, Yu W. Ethanolthermal synthesis to CuI nanocrystals at low temperature. J Mater Sci Lett 2001;20:1865–7. [6] Boschloo G, Hagfeldt A. Characteristics of the iodide/triiodide redox mediator in DSSC. Acc Chem Res 2009;42:1819–26. [7] Li D, Qin D, Deng M, Luo Y, Meng Q. Optimization the solid-state electrolytes for DSSC. Energy Environ Sci 2009;2:283–91. [8] Sun L, Ichinose K, Sekiya T, Sugiura T, Yoshida T. Cathodic electrodeposition of p-CuSCN nanorod and its dye-sensitized photocathodic property. Phys Proc 2011;14:12–24. [9] Kumarasinghe AR, Flavell WR, Thomas AG, Mallick AK, Tsoutsou D, Chatwin C, et al. Electronic properties of the interface between p-CuI and n-TiO2 single crystal and nanoparticulate surfaces. J Chem Phys 2007;127:114703. [10] Takeda T, Matsunaga K-i, Uruga T, Takakura M, Fujiwara T. CuI-catalyzed regioselective allylation of pyridylthioallylstannanes—A new route to m-unsaturated ketones. Tetrahedron Lett 1997;38:2879–82. [11] Tanji A, Akai I, Kojima K, Karasawa T, Komatsu T. Exciton transitions in the hexagonal CuI microcrystallites grown on polymers. J Lumin 2000;87:516–8. [12] Tennakone K, Kumara GRRA, Kottegoda IRM, Perera VPS, Aponsu GMLP, Wijayantha KGU. Deposition of thin films of CuI on glass. Sol Energy Mater Sol Cells 1998;55:283–9. [13] Johan MRS-W, Kok Hawari, Norliza Khalisah Aznan, Nurul Azri. Synthesis and characterization of CuI nanoparticles via chemical route. Int J Electrochem Sci 2012;7:4942. [14] Xu Y, Yang S, Zhang G, Sun Y, Gao D, Sun Y. Fabrication, characterization and optical property of CuI nanospheres. Mater Lett 2011;65:1699–702.
S. Shahbazi, S. Afshar / Materials Letters 115 (2014) 190–193
[15] Ma Y, Gu M, Huang S, Liu X, Liu B, Ni C. Colloidal synthesis of uniform CuI nanoparticles and size dependent optical properties. Mater Lett 2013;100: 166–9. [16] Tavakoli F, Salavati-Niasari M, Mohandes F. Green synthesis of flower-like CuI microstructures composed of trigonal nanostructures using pomegranate juice. Mater Lett 2013;100:133–6. [17] Tadjarodi A, Izadi M, Imani M. Synthesis and characterization of the special ZnO nanostructure by mechanochemical process. Mater Lett 2013;92:108–10. [18] Huot J, Ravnsbk DB, Zhang J, Cuevas F, Latroche M, Jensen TR. Mechanochemical synthesis of hydrogen storage materials. Prog Mater Sci 2013;58:30–75.
193
[19] Nasiri-Tabrizi B, Fahami A, Ebrahimi-Kahrizsangi R, Khazraei A, Yazdani MR, Kajbafzadeh MJ. A study on mechanochemical behavior of CaO–P2O5–CaF2– ZrO2 to produce fluorapatite–zirconia composite. Powder Technol 2013;243: 59–70. [20] Sharma B, Rabinal MK. synthesis and optoelectronic properties of CuI semiconductor nanoparticles. J Alloys Compd 2013;556:198–202. [21] Chen D, Wang Y, Lin Z, Huang J, Chen X, Pan D, et al. Growth strategy and physical properties of the high mobility p-type CuI crystal. Crys Growth Des 2010;10:2057–60.
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
A facile, green, one pot synthesis of cuprous iodide nanoparticles using the mechanochemical method Saeed Shahbazi, Shahrara Afshar n Department of Chemistry, Iran University of Science and Technology, 16846-13114 Tehran, Iran
art ic l e i nf o
a b s t r a c t
Article history: Received 10 September 2013 Accepted 5 October 2013 Available online 24 October 2013
Cuprous iodide, that recently has been used as an inorganic hole (vacant state) conductor material in dye sensitized solar cells, was successfully synthesized with a rapid, low cost, one pot and solvent free reaction using the mechanochemical method. The XRD data showed that all peaks matched well with those of the gamma phase of CuI. In addition, EDX analysis confirmed the formation of 100% pure CuI compound. Moreover, the SEM images showed the nanosized spherical morphology of 40–70 nm. The diffuse reflectance spectrum (DRS) of the product showed that CuI nanoparticles have a maximum absorption at about 400 nm and a band gap of 3 eV. The results of this contribution corroborate the successful synthesis of pure cuprous iodide (CuI) nanoparticles. & 2013 Elsevier B.V. All rights reserved.
Keywords: Cuprous iodide Green chemistry Mechanochemical method Nanoparticles Solar energy materials
1. Introduction Cuprous iodide (CuI) has many features that derived much attention during the last decade. It has large band gap, an unusually large temperature dependency and large iconicity [1,2]. This compound has also been applied as a potent catalyst for organic compound syntheses [3], ultrafast scintillators [4], and super ionic conductors, solid-state solar cells, etc. [5]. One of the main components of dye solar cells is electrolyte. Iodine-triiodide liquid electrolyte is a composition frequently used in dye solar cells [6]. However despite having a good performance as liquid electrolytes, it suffers from drawbacks such as volatility, corrosion and sealing problems that decrease the stability of the cells [7]. Hence, replacing the liquid electrolyte with solid electrolytes is one of the major challenges in producing of dye solar cells. Solid electrolytes among others have attracted much attention due to their high stability, high hole transfer speed and physical contact at the interface of a metal oxide/dye/electrolyte [7]. CuI and CuSCN are used as solid electrolytes in dye sensitized solar cells since a good overlap exists between the bands of CuI and dye [8,9]. Cuprous iodide has been prepared using several physical methods such as electrodepositing [10], pulse laser deposition [11], vacuum evaporation [12]. And different chemical methods have been reported on preparing CuI, such as the liquid phase reaction [13], low temperature solvothermal synthesis [5], coprecipitation [14], and precipitation method using capping agent and pomegranate juice [15,16]. Although the above mentioned
n
Corresponding author. Tel.: þ 98 21 7724 0288; fax: þ 98 21 7322 2705. E-mail address: [email protected] (S. Afshar).
0167-577X/$ - see front matter & 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.matlet.2013.10.072
methods may have some advantages and despite significant gains in the past, still finding a new route for green, facile and scale-up preparation of the cuprous iodide remains a challenge. In recent years, numerous scientists and technologist have paid much attention to solid state reactions because of their simplicity of application in large scale, low-cost and high efficiency. Mechanochemical processes are used to prepare different kinds of nanostructures of metal oxides [17], hydrogen storage materials [18], composites [19] and so on. Since no toxic liquid solvent have been used in these reactions, they do not pollute the environment and therefore these reactions can be considered as green chemistry methodologies. The above advantages have made the researchers to be high concerned about the mechanochemical methods compared to the other synthetic routes. In this work, for the first time, a mechanochemical method is used for the synthesis of the spherical γ-CuI nanoparticles at room temperature. This study introduces a facile, green and an easiest possible one-pot method for the synthesis of CuI compound. The proposed method has solvent-free characteristic which would result in a lower cost and being environmentally favored. In addition, the procedure of CuI synthesis is very easy in the presented work.
2. Material and method CuSO4 (99%) and KI (99.5%) were purchased from Merck Company and were used without further purification. In a stainless steel (10 mL) vial a mixture of CuSO4 and KI solids with a molar ratio of 1:2 were milled together using a Mixer Mill (Retsch MM-400) apparatus at 1800 rpm (30 Hz) for 40 min at room temperature. The brown powder as a product was expected
S. Shahbazi, S. Afshar / Materials Letters 115 (2014) 190–193
to be a mixture of cuprous iodide, molecular iodine and potassium sulfate. The mixture was washed with deionized water to remove molecular iodine and potassium sulfate salt. The precipitate was then dried in a vacuum oven at 100 1C for 2 h to obtain the final grayish white product. X-ray powder diffraction pattern (XRD) was performed on a SIEFERT XRD 3003 PTS diffractometer using Cu Kα irradiation (λ ¼1.5418 Å). Scanning electron micrographs and energy dispersive X-ray Spectroscopy were taken with a ZEISS-DSM 960A microscope with attached camera operating at 30 kV to determine the morphology, particle size and high purity of as-prepared synthesized salt. Diffuse reflectance spectrum (DRS) was measured on a TU-1901 spectrophotometer. All the measurements were done at room temperature.
3. Results and discussion Copper forms a variety of compounds with oxidation states of þ1 and þ2. In aqueous solution and for the most ligands, it is the þ2 oxidation state of the copper that dominates and is the more stable one. However, the reducing ligands, like iodide would reduce the Cu2 þ ions to the þ 1 oxidation state. Therefore, after milling the precursors, the brown powder as product was expected to be a mixture of cuprous iodide, molecular iodine and potassium sulfate. The reaction equation is as follows: 2CuSO4 þ 4KI-2CuI þ I2 þ 2K2 SO4
ð1Þ
191
In this reaction, Cu2 þ and I act as oxidizing and reducing agents, respectively. To explore the formation of the CuI and in order to identify its phase and structure X-ray diffraction pattern was used. 2θ values and their matching hkl indices are shown in Fig. 1, stating the gamma phase of CuI (JCPDS Card No. 06-0246) and indicating the formation of CuI in a cubic lattice with cell parameter (a) equal to 6.06 Å. This ratify that CuI has been formed without any impurity [15]. The particle size of the CuI powder was estimated by applying Scherrer's equation [20] and was found to be equal to 40 nm. The morphology of the obtained product was investigated by scanning electron microscopy (SEM). As can be seen in Fig. 2a and b, the SEM images show that the CuI powder is consisted of spherical nanoparticles with the size of 40–70 nm, which is very close to that obtained by XRD analysis. Also the crystallites are uniformly aggregated. The purity of the prepared CuI nanoparticles was also evidenced by the EDX pattern showed in Fig. 2c. The EDX measurement verified the existence of copper and iodide in the final product. This analysis showed a purity of 100% for the synthesized compound which is in good agreement with the XRD data. The optical absorption of the as-prepared CuI was investigated in the wavelength range of 300–800 nm. Based on the theory of optical absorption, the relation between the absorption coefficient and photon energy is as follows [20]: ahν ¼ Aðhν Eg Þ1=2
Fig. 1. (a) XRD pattern of the CuI nanoparticles; (b) the plot of (αhѵ)2 vs. hѵ and (c) optical absorption spectrum of obtained CuI nanoparticles.
ð2Þ
192
S. Shahbazi, S. Afshar / Materials Letters 115 (2014) 190–193
Fig. 2. (a,b) SEM images of CuI nanoparticles. (c) EDX pattern of synthesized product.
where here hν is the photon energy, A is a constant and Eg is the band gap. Fig. 1b and c show the plot of (ahν)2 vs. hν and the optical absorption spectrum for the as-prepared CuI nanoparticles, respectively. The size plays a significant role on the band gap of the nanoparticles and therefore on the applications that they can have. Different band gap values ranging from 2.9 to 4.2 eV are reported for the cuprous iodide in the literature. For the single crystal form of this compound, the band gap is reported to be 2.9 eV [21] and for the 20 nm particles, it is 4.77 eV [20]. In the present work the band gap for CuI was found to be 3 eV, which was obtained by extrapolation of the straight line at (ahν)2 ¼ 0. The small differences observed between the calculated band gap and the reported values in the literatures arise from agglomeration of CuI nanoparticles that can be seen in SEM images.
4. Conclusion In summary, gamma phase of CuI with the spherical morphology of particles was successfully synthesized using the mechanochemical procedure. The XRD and DRS characterizations of these nanoparticles revealed a pure gamma phase with the bang gap of about 3 eV. This facile, green and easy one-pot method for the synthesis of CuI compound is reported for the very first time. The proposed method in this work has many advantages, such as having solvent-free characteristics which result in lower costs, being environmentally favored amid a very easy procedure for the synthesis route. This glib synthesis method has a superior capability for the development and application of the solar cells in the industrial scales.
References [1] Ferhat M, Zaoui A, Certier M, Dufour JP, Khelifa B. Electronic structure of the copper halides CuCl, CuBr and CuI. Mater Sci Eng: B 1996;39:95–100. [2] Feraoun H, Aourag H, Certier M. Theoretical studies of stoichiometric CuI. Mater Chem Phys 2003;82:597–601. [3] Ziarati A, Safaei-Ghomi J, Rohani S. Pseudo five-component process for the synthesis of functionalized tricarboxamides using CuI as reusable catalyst. Chin Chem Lett 2013;24:195–8. [4] Gao P, Gu M, Liu X-L, Liu B, Huang S-M. Luminescence of CuI single crystals: On the nature of red luminescence. Appl Phys Lett 2009221904-3. [5] Liu Y, Zhan J, Zeng J, Qian Y, Tang K, Yu W. Ethanolthermal synthesis to CuI nanocrystals at low temperature. J Mater Sci Lett 2001;20:1865–7. [6] Boschloo G, Hagfeldt A. Characteristics of the iodide/triiodide redox mediator in DSSC. Acc Chem Res 2009;42:1819–26. [7] Li D, Qin D, Deng M, Luo Y, Meng Q. Optimization the solid-state electrolytes for DSSC. Energy Environ Sci 2009;2:283–91. [8] Sun L, Ichinose K, Sekiya T, Sugiura T, Yoshida T. Cathodic electrodeposition of p-CuSCN nanorod and its dye-sensitized photocathodic property. Phys Proc 2011;14:12–24. [9] Kumarasinghe AR, Flavell WR, Thomas AG, Mallick AK, Tsoutsou D, Chatwin C, et al. Electronic properties of the interface between p-CuI and n-TiO2 single crystal and nanoparticulate surfaces. J Chem Phys 2007;127:114703. [10] Takeda T, Matsunaga K-i, Uruga T, Takakura M, Fujiwara T. CuI-catalyzed regioselective allylation of pyridylthioallylstannanes—A new route to m-unsaturated ketones. Tetrahedron Lett 1997;38:2879–82. [11] Tanji A, Akai I, Kojima K, Karasawa T, Komatsu T. Exciton transitions in the hexagonal CuI microcrystallites grown on polymers. J Lumin 2000;87:516–8. [12] Tennakone K, Kumara GRRA, Kottegoda IRM, Perera VPS, Aponsu GMLP, Wijayantha KGU. Deposition of thin films of CuI on glass. Sol Energy Mater Sol Cells 1998;55:283–9. [13] Johan MRS-W, Kok Hawari, Norliza Khalisah Aznan, Nurul Azri. Synthesis and characterization of CuI nanoparticles via chemical route. Int J Electrochem Sci 2012;7:4942. [14] Xu Y, Yang S, Zhang G, Sun Y, Gao D, Sun Y. Fabrication, characterization and optical property of CuI nanospheres. Mater Lett 2011;65:1699–702.
S. Shahbazi, S. Afshar / Materials Letters 115 (2014) 190–193
[15] Ma Y, Gu M, Huang S, Liu X, Liu B, Ni C. Colloidal synthesis of uniform CuI nanoparticles and size dependent optical properties. Mater Lett 2013;100: 166–9. [16] Tavakoli F, Salavati-Niasari M, Mohandes F. Green synthesis of flower-like CuI microstructures composed of trigonal nanostructures using pomegranate juice. Mater Lett 2013;100:133–6. [17] Tadjarodi A, Izadi M, Imani M. Synthesis and characterization of the special ZnO nanostructure by mechanochemical process. Mater Lett 2013;92:108–10. [18] Huot J, Ravnsbk DB, Zhang J, Cuevas F, Latroche M, Jensen TR. Mechanochemical synthesis of hydrogen storage materials. Prog Mater Sci 2013;58:30–75.
193
[19] Nasiri-Tabrizi B, Fahami A, Ebrahimi-Kahrizsangi R, Khazraei A, Yazdani MR, Kajbafzadeh MJ. A study on mechanochemical behavior of CaO–P2O5–CaF2– ZrO2 to produce fluorapatite–zirconia composite. Powder Technol 2013;243: 59–70. [20] Sharma B, Rabinal MK. synthesis and optoelectronic properties of CuI semiconductor nanoparticles. J Alloys Compd 2013;556:198–202. [21] Chen D, Wang Y, Lin Z, Huang J, Chen X, Pan D, et al. Growth strategy and physical properties of the high mobility p-type CuI crystal. Crys Growth Des 2010;10:2057–60.