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Facile synthesis of crystal like shape mesoporous silica SBA-16
Microporous and Mesoporous Materials 97 (2006) 141–144 www.elsevier.com/locate/micromeso
Facile synthesis of crystal like shape mesoporous silica SBA-16 Hongxiao Jin a, Qingyin Wu b
a,*
, Chao Chen b, Daliang Zhang b, Wenqin Pang
a,b,*
a Department of Chemistry, Zhejiang University, Hangzhou 310027, PR China State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Department of Chemistry, Jilin University, Changchun 130023, PR China
Received 13 September 2005; received in revised form 16 May 2006; accepted 9 August 2006 Available online 18 September 2006
Abstract A simple synthesis of single crystal like mesoporous SBA-16 silica with decaoctahedron shape and rhomb-dodecahedron shape has been accomplished by finely tuning of overall composition of the synthesis mixture (F127–TEOS–H2O–HCl), under static condition at 26–34 °C in 3–72 h. Ó 2006 Elsevier Inc. All rights reserved. Keywords: SBA-16; F127; Crystal; Decaoctahedron; Rhomb-dodecahedron
1. Introduction Morphosynthesis [1–3] (fabrication of materials with controllable morphologies) of mesoporous materials have attracted a lot of attention over the last several years for the purpose of providing catalytic, separation, and adsorption applications [4–7]. All of these applications greatly depend on not only the intraparticle mesoporous structures, but also the shape of these materials that affects the interparticle mass transport processes. It is of particular interesting for a periodical mesoporous material to show a crystal like morphology. Because it could offer new opportunities for their application in field such as separation, optoelectronic, photo devices, sensing, catalysis, and drug delivery [8–21]. Several recent reports have focused on the fabrication of mesoporous silica [8– 19], organosilicates [20] and non-oxidic [21,22] porous mesostructured materials with crystal like morphology. However, in most of these reports, ionic surfactants have been used. Rare examples of the synthesis of single crystal mesoporous material were found using non-ionic tri-block * Corresponding authors. Tel.: +86 571 87952608; fax: +86 571 87951895 (Qingyin Wu); Tel./fax: +86 431 5168590 (Wenqin Pang). E-mail addresses: [email protected] (Q. Wu), [email protected] (W. Pang).
1387-1811/$ - see front matter Ó 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.micromeso.2006.08.008
copolymer as template [15–19]. It is believed this is due to the specific interaction of surfactant and inorganic species in solution [16]. Herein, we present a simple synthesis of SBA-16 crystals with highly ordered pore structure under static conditions by carefully control of the reaction temperature and reactants ratio. Crystal like mesoporous silica SBA-16 with decaoctahedron and rhomb-dodecahedron shape is obtained. 2. Experimental section 2.1. Synthesis of materials The preparation procedure was as follow: triblock copolymer Pluronic F127 was added to HCl aqueous solution and allowed to stirred at a certain temperature overnight. Then, TEOS was added to this solution under vigorous stirring. After 10 min stirring, the mixture was kept under static conditions at aforementioned temperature for 3–72 h. The solid products were collected by filtration, washed with ethanol, dried, and calcined at 550 °C in air for 5 h. The preparation of SBA-16 single crystals relies on the control of the reaction temperature and the reactants ratio. The typical synthetic condition is 1.00TEOS: 0.0041F127:5.00HCl:180H2O at 28 °C for decaoctahedron
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H. Jin et al. / Microporous and Mesoporous Materials 97 (2006) 141–144
shape, and 1.00TEOS:0.0053F127:4.10HCl:150H2O at 32 °C for rhomb-dodecahedron shape. 2.2. Characterization of materials XRD patterns were recorded on a SIEMENS D8 ADVANCE powder diffraction system using Cu Ka ˚ ) radiation (40 kV and 40 mA). The scanning (k = 1.5418 A electron micrographs (SEM) were taken on FEI SIRION electron microscope with an acceleration voltage of 5 KV. The samples were deposited on a sample holder with an adhesive carbon foil and sputtered with gold prior to imaging. Transmission electron microscopy (TEM) measurements were taken on a JEM-3010 electron microscope (JEOL, Japan) with an acceleration voltage of 300 KV. The nitrogen sorption experiments were performed at 196 °C on Micromeritics ASAP 2010M systems. The samples were outgassed at 300 °C for 10 h before the measurement. The pore diameter was calculated from the analysis of desorption branch of the isotherm by the BJH (Barrett–Joyner–Halenda) method. 3. Results and discussion As revealed by scanning electron microscopy (SEM), the crystal like mesoporous silica SBA-16 of decaoctaheron shape was obtained in diameter of 2–6 lm (part a and b in Fig. 1). It is composed of six squares and 12 elongated hexagons, which could be described as a rhomb-dodecahedron whose acute angles are truncated by squares. Part c in Fig. 1 show the schematic drawing of this morphology viewed from x-axis. This morphology is commonly found in ionic surfactant templated mesoporous crystals (SBA1, MCM-48, hybrid silica) [8–14,20]. However, it is rare in nonionic surfactant templated mesoporous crystals [17]. Low-angle X-ray diffraction (XRD) measurement (part d in Fig. 1) shows that the calcined powder exhibits five diffraction peaks in the region of 2h = 0.9–1.8°, which are indexed to the 1 1 0, 2 0 0, 2 1 1, 2 2 0 and 3 1 0 diffractions of cubic symmetry [23] with a lattice constant of a0 = 14 nm. The observation on the TEM micrograph (part f in Fig. 1) is in agreement with this structure. The corresponding nitrogen adsorption/desorption measurements give type-IV isotherms with a H2 hysteresis loop (part e in Fig. 1), which suggests that the mesopores are cage like. The average pore diameter was calculated to be 7.4 nm from the adsorption branch of the isotherm by using the Barrett–Joyner–Halenda (BJH) method. The analysis results give a pore volume of 0.6 cm3/g, a BET surface area of 760 m2/g. Similar like the decaoctaheron shape, the rhombdodecahedron shape SBA-16 is also of 2–6 lm in diameter (parts a and b in Fig. 2). The rhomb-dodecahedron shape SBA-16 is composed of 12 rhombs, part c in Fig. 2 shows the schematic drawing of this morphology. The evidence for the mesostructure is provided by TEM images (parts d, e and f in Fig. 2). The results show a well-ordered cubic
Fig. 1. Calcined SBA-16 of decaoctahedron shape: (a, b) SEM image. (c) Schematic drawing of morphology. (d) XRD pattern. (e) N2 adsorption/ desorption isotherm. (f) TEM images taken at [1 1 1] incidences.
mesoporous structure viewed along the 1 0 0, 1 1 0 and 1 1 1 direction, which confirm these mesoporous silica has a highly ordered cubic structure with a lattice constant of a0 = 11 nm. The lattice value is in accordance with the XRD result (part f in Fig. 2) in which the number is a0 = 11.8 nm. Similar with the decaoctaheron shape SBA16, the nitrogen adsorption/desorption measurement of
H. Jin et al. / Microporous and Mesoporous Materials 97 (2006) 141–144
143
Fig. 2. Calcined SBA-16 of Rhomb-dodecahedron shape: (a, b) SEM image. (c) Schematic drawing of morphology. (d)–(f) TEM images taken at [1 0 0], [1 1 0], [1 1 1] incidences. (g) XRD pattern. (h) N2 adsorption/desorption isotherms.
rhomb-dodecahedron shape SBA-16 is also of type-IV isotherms with a H2 hysteresis loop (part g in Fig. 2). Further analysis of the nitrogen physisorption result suggests that the average pore diameter, pore volume and BET surface area is 5.5 nm, 0.44 cm3/g and 650 m2/g, respectively. Both of these two crystals show intrinsic cubic structure and the results show a diversity of single crystal like morphologies. However, the unit cell parameter and pore diameter in decaoctaheron shape crystals appeared to be larger than those of rhomb-dodecahedron shape crystals, while the wall thickness expansion (6.6 nm vs. 6.3 nm) is minor. Since 1.5 M HCl was used in the synthesis of these two crystals, we assume that the differences are due to the synthetic temperature and the concentration of silicates and F127. According to the cooperative templating model for meoporous silica synthesis, the formation of the mesophase is both kinetically and thermodynamically determined process [24,25]. Due to the complexity of the self-assemble of surfactants and silicates, it is difficult to obtain a ‘‘pure’’ crystal phase with one kind shape. Other kind shapes were always found in our synthetic condition, as shown in Fig. 3, under the synthetic condition:
Fig. 3. Various kind morphologies were obtained in a single synthesis batch: 1. Rhomb-dodecahedron shape. 2. Decaoctahedron shape. 3. Sphere. 4. Other shape.
1.00TEOS:0.0050F127:3.60HCl:160H2O at 30 °C, various kind morphology, could be obtained in a single batch. Moreover, the yield of the synthesis (based on silica recovery) is about 90%, this is due to the incomplete condensation of silicates in the solution.
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H. Jin et al. / Microporous and Mesoporous Materials 97 (2006) 141–144
tion temperature and reactants ratio; the results show a diversity of single crystal like morphologies. Crystal like mesoporous silica SBA-16 with decaoctahedron and rhomb-dodecahedron shape is obtained. The typical synthetic condition is 1.00TEOS:0.0041F127:5.00HCl:180H2O at 28 °C for decaoctahedron shape, and 1.00TEOS: 0.0053F127:4.10HCl:150H2O at 32 °C for rhomb-dodecahedron shape. Acknowledgements
Fig. 4. Effect of hydrothermal treatment: the decaoctahedron shape like SBA-16.
The synthetic conditions should be carefully controlled in order to obtain high yield of the ‘‘target’’ crystal. Lower surfactant concentration could not lead to meosporous silica, and higher concentration would not promote the surfactant/silicates condensation. Mildly acidic conditions (1.2–1.7 M HCl) and a moderate reaction temperature (26–34 °C) were necessary for the syntheses. Stronger acidity or higher temperature would promote a rapid, uncontrolled hydrolysis/condensation of silica species that would not lead to the formation of crystals with a regular morphology. Weaker acidity with an HCl concentration less than 1.2 M would lead to the formation of other mesoporous structure [26], and lower reaction temperature would result in materials with amorphous morphology and poorly ordered mesostructures. For instance, a relatively lower F127 concentration and reaction temperature favors the formation of decaoctahedral shape, while higher F127 concentration and higher reaction temperature proves rhomb-dodecahedron shape. In general, the hydrothermal treatment would improve the silicates condensation, the stability of the mesoporous materials and enlarge the pore size. But in the crystal like morphology synthesis, further hydrothermal treatment of the powder with mother solution is not recommended. Complete condensation of the silicates in the solution through hydrothermal treatment would not derive SBA16 with good crystal morphology. For example, in the decaoctahedron shape like SBA-16 synthesis, small spheres other than crystals would form on the surface of the crystals after the sample was hydrothermal treated at 100 °C for 72 h (Fig. 4). As shown in a recent publication [18], the evolution of spheres was likely due to the degradation of the surfactant.
The authors acknowledge the financial support of the State Basic Research Project of China (G200077507), the National Natural Science Foundation of China (Grant Nos. 20233030, 20271045), and the State Key Laboratory of Inorganic Synthesis and Preparative Chemistry of Jilin University. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24]
4. Conclusions In this study, a simple synthesis of SBA-16 crystals under static was carried out by merely control of the reac-
[25] [26]
M. Antonietti, G.A. Ozin, Chem. Eur. J. 10 (2004) 28. H. Co¨lfen, S. Mann, Angew. Chem. Int. Ed. 42 (2003) 2350. E. Dujardin, S. Mann, Angew. Chem. Int. Ed. 13 (2002) 775. P. Schmidt-Winkel, P. Yang, D.I. Margolese, B.F. Chmelka, G.D. Stucky, Adv. Mater. 11 (1999) 303. H.-P. Lin, C.-Y. Mou, Acc. Chem. Res. 35 (2002) 927. B.-H. Han, W. Zhou, A. Sayari, J. Am. Chem. Soc. 125 (2003) 3444. A. Sayari, B.-H. Han, Y. Yang, J. Am. Chem. Soc. 126 (2004) 14348. S.K. Kim, R. Ryoo, Chem. Commun. 2 (1998) 259. M. Kaneda, T. Tsubakiyama, A. Carlsson, Y. Sakamoto, T. Ohsuna, O. Terasaki, J. Phys. Chem. B 106 (2002) 1256. S. Che, Y. Sakamoto, O. Terasaki, T. Tatsumi, Chem. Mater. 13 (2001) 2237. M.-C. Chao, D.-S. Wang, H.-P. Lin, C.-Y. Mou, J. Mater. Chem. 13 (2003) 2853. Y. Sakamoto, M. Kneda, O. Terasaki, D. Zhao, J.M. Kim, G.D. Stucky, H.J. Shin, R. Ryoo, Nature 408 (2000) 449. S. Che, S. Lim, M. Kneda, H. Yoshitake, O. Terasaki, T. Tatsumi, J. Am. Chem. Soc. 124 (2002) 13962. J. Wang, C.K. Tsung, Y. Wu, G.D. Stucky, Angew. Chem. Int. Ed. 44 (2005) 332. C. Yu, B. Tian, J. Fan, G.D. Stucky, D. Zhao, J. Am. Chem. Soc. 124 (2002) 4556. C. Yu, B. Tian, J. Fan, D. Zhao, Chem. Mater. 16 (2004) 880. Y.K. Hwang, J.S. Chang, Y.U. Kwon, S.E. Park, Micropor. Mesopor. Mater. 68 (2004) 21. M. Mesa, L. Sierra, J. Patarin, J.L. Guth, Solid State Sci. 990 (2005) 7. L. Sierra, M. Mesa, A. Ramirez, B. Lopez, J.L. Guth, Stud. Surf. Sci. Catal. Part A–C 573 (2004) 154. S. Guan, S. Iagaki, T. Ohsuna, O. Terasaki, J. Am. Chem. Soc. 122 (2000) 5660. P.N. Trikalitis, N. Ding, C. Malliakas, S.J.L. Billinge, M.G. Kanatzidis, J. Am. Chem. Soc. 126 (2004) 15326. P.N. Trikalitis, K.K. Rangan, T. Bakas, M.G. Kanatzidis, J. Am. Chem. Soc. 124 (2002) 12255. F. Kleitz, L.A. Solovyov, G.A. Anikumar, S.H. Choi, R. Ryoo, Chem. Commun. 13 (2004) 1536. J.Y. Ying, C.P. Mehnert, M.S. Wong, Angew. Chem. Int. Ed. 38 (1999) 56. J. Patarin, B. Lebeau, R. Zana, Curr. Opin. Colloid Interface Sci. 7 (2002) 107. F. Kleitz, D. Liu, G.M. Anikumar, I.-S. Park, L.A. Solovyov, A.N. Shmakov, R. Ryoo, J. Phys. Chem. B 107 (2003) 14926.
Facile synthesis of crystal like shape mesoporous silica SBA-16 Hongxiao Jin a, Qingyin Wu b
a,*
, Chao Chen b, Daliang Zhang b, Wenqin Pang
a,b,*
a Department of Chemistry, Zhejiang University, Hangzhou 310027, PR China State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Department of Chemistry, Jilin University, Changchun 130023, PR China
Received 13 September 2005; received in revised form 16 May 2006; accepted 9 August 2006 Available online 18 September 2006
Abstract A simple synthesis of single crystal like mesoporous SBA-16 silica with decaoctahedron shape and rhomb-dodecahedron shape has been accomplished by finely tuning of overall composition of the synthesis mixture (F127–TEOS–H2O–HCl), under static condition at 26–34 °C in 3–72 h. Ó 2006 Elsevier Inc. All rights reserved. Keywords: SBA-16; F127; Crystal; Decaoctahedron; Rhomb-dodecahedron
1. Introduction Morphosynthesis [1–3] (fabrication of materials with controllable morphologies) of mesoporous materials have attracted a lot of attention over the last several years for the purpose of providing catalytic, separation, and adsorption applications [4–7]. All of these applications greatly depend on not only the intraparticle mesoporous structures, but also the shape of these materials that affects the interparticle mass transport processes. It is of particular interesting for a periodical mesoporous material to show a crystal like morphology. Because it could offer new opportunities for their application in field such as separation, optoelectronic, photo devices, sensing, catalysis, and drug delivery [8–21]. Several recent reports have focused on the fabrication of mesoporous silica [8– 19], organosilicates [20] and non-oxidic [21,22] porous mesostructured materials with crystal like morphology. However, in most of these reports, ionic surfactants have been used. Rare examples of the synthesis of single crystal mesoporous material were found using non-ionic tri-block * Corresponding authors. Tel.: +86 571 87952608; fax: +86 571 87951895 (Qingyin Wu); Tel./fax: +86 431 5168590 (Wenqin Pang). E-mail addresses: [email protected] (Q. Wu), [email protected] (W. Pang).
1387-1811/$ - see front matter Ó 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.micromeso.2006.08.008
copolymer as template [15–19]. It is believed this is due to the specific interaction of surfactant and inorganic species in solution [16]. Herein, we present a simple synthesis of SBA-16 crystals with highly ordered pore structure under static conditions by carefully control of the reaction temperature and reactants ratio. Crystal like mesoporous silica SBA-16 with decaoctahedron and rhomb-dodecahedron shape is obtained. 2. Experimental section 2.1. Synthesis of materials The preparation procedure was as follow: triblock copolymer Pluronic F127 was added to HCl aqueous solution and allowed to stirred at a certain temperature overnight. Then, TEOS was added to this solution under vigorous stirring. After 10 min stirring, the mixture was kept under static conditions at aforementioned temperature for 3–72 h. The solid products were collected by filtration, washed with ethanol, dried, and calcined at 550 °C in air for 5 h. The preparation of SBA-16 single crystals relies on the control of the reaction temperature and the reactants ratio. The typical synthetic condition is 1.00TEOS: 0.0041F127:5.00HCl:180H2O at 28 °C for decaoctahedron
142
H. Jin et al. / Microporous and Mesoporous Materials 97 (2006) 141–144
shape, and 1.00TEOS:0.0053F127:4.10HCl:150H2O at 32 °C for rhomb-dodecahedron shape. 2.2. Characterization of materials XRD patterns were recorded on a SIEMENS D8 ADVANCE powder diffraction system using Cu Ka ˚ ) radiation (40 kV and 40 mA). The scanning (k = 1.5418 A electron micrographs (SEM) were taken on FEI SIRION electron microscope with an acceleration voltage of 5 KV. The samples were deposited on a sample holder with an adhesive carbon foil and sputtered with gold prior to imaging. Transmission electron microscopy (TEM) measurements were taken on a JEM-3010 electron microscope (JEOL, Japan) with an acceleration voltage of 300 KV. The nitrogen sorption experiments were performed at 196 °C on Micromeritics ASAP 2010M systems. The samples were outgassed at 300 °C for 10 h before the measurement. The pore diameter was calculated from the analysis of desorption branch of the isotherm by the BJH (Barrett–Joyner–Halenda) method. 3. Results and discussion As revealed by scanning electron microscopy (SEM), the crystal like mesoporous silica SBA-16 of decaoctaheron shape was obtained in diameter of 2–6 lm (part a and b in Fig. 1). It is composed of six squares and 12 elongated hexagons, which could be described as a rhomb-dodecahedron whose acute angles are truncated by squares. Part c in Fig. 1 show the schematic drawing of this morphology viewed from x-axis. This morphology is commonly found in ionic surfactant templated mesoporous crystals (SBA1, MCM-48, hybrid silica) [8–14,20]. However, it is rare in nonionic surfactant templated mesoporous crystals [17]. Low-angle X-ray diffraction (XRD) measurement (part d in Fig. 1) shows that the calcined powder exhibits five diffraction peaks in the region of 2h = 0.9–1.8°, which are indexed to the 1 1 0, 2 0 0, 2 1 1, 2 2 0 and 3 1 0 diffractions of cubic symmetry [23] with a lattice constant of a0 = 14 nm. The observation on the TEM micrograph (part f in Fig. 1) is in agreement with this structure. The corresponding nitrogen adsorption/desorption measurements give type-IV isotherms with a H2 hysteresis loop (part e in Fig. 1), which suggests that the mesopores are cage like. The average pore diameter was calculated to be 7.4 nm from the adsorption branch of the isotherm by using the Barrett–Joyner–Halenda (BJH) method. The analysis results give a pore volume of 0.6 cm3/g, a BET surface area of 760 m2/g. Similar like the decaoctaheron shape, the rhombdodecahedron shape SBA-16 is also of 2–6 lm in diameter (parts a and b in Fig. 2). The rhomb-dodecahedron shape SBA-16 is composed of 12 rhombs, part c in Fig. 2 shows the schematic drawing of this morphology. The evidence for the mesostructure is provided by TEM images (parts d, e and f in Fig. 2). The results show a well-ordered cubic
Fig. 1. Calcined SBA-16 of decaoctahedron shape: (a, b) SEM image. (c) Schematic drawing of morphology. (d) XRD pattern. (e) N2 adsorption/ desorption isotherm. (f) TEM images taken at [1 1 1] incidences.
mesoporous structure viewed along the 1 0 0, 1 1 0 and 1 1 1 direction, which confirm these mesoporous silica has a highly ordered cubic structure with a lattice constant of a0 = 11 nm. The lattice value is in accordance with the XRD result (part f in Fig. 2) in which the number is a0 = 11.8 nm. Similar with the decaoctaheron shape SBA16, the nitrogen adsorption/desorption measurement of
H. Jin et al. / Microporous and Mesoporous Materials 97 (2006) 141–144
143
Fig. 2. Calcined SBA-16 of Rhomb-dodecahedron shape: (a, b) SEM image. (c) Schematic drawing of morphology. (d)–(f) TEM images taken at [1 0 0], [1 1 0], [1 1 1] incidences. (g) XRD pattern. (h) N2 adsorption/desorption isotherms.
rhomb-dodecahedron shape SBA-16 is also of type-IV isotherms with a H2 hysteresis loop (part g in Fig. 2). Further analysis of the nitrogen physisorption result suggests that the average pore diameter, pore volume and BET surface area is 5.5 nm, 0.44 cm3/g and 650 m2/g, respectively. Both of these two crystals show intrinsic cubic structure and the results show a diversity of single crystal like morphologies. However, the unit cell parameter and pore diameter in decaoctaheron shape crystals appeared to be larger than those of rhomb-dodecahedron shape crystals, while the wall thickness expansion (6.6 nm vs. 6.3 nm) is minor. Since 1.5 M HCl was used in the synthesis of these two crystals, we assume that the differences are due to the synthetic temperature and the concentration of silicates and F127. According to the cooperative templating model for meoporous silica synthesis, the formation of the mesophase is both kinetically and thermodynamically determined process [24,25]. Due to the complexity of the self-assemble of surfactants and silicates, it is difficult to obtain a ‘‘pure’’ crystal phase with one kind shape. Other kind shapes were always found in our synthetic condition, as shown in Fig. 3, under the synthetic condition:
Fig. 3. Various kind morphologies were obtained in a single synthesis batch: 1. Rhomb-dodecahedron shape. 2. Decaoctahedron shape. 3. Sphere. 4. Other shape.
1.00TEOS:0.0050F127:3.60HCl:160H2O at 30 °C, various kind morphology, could be obtained in a single batch. Moreover, the yield of the synthesis (based on silica recovery) is about 90%, this is due to the incomplete condensation of silicates in the solution.
144
H. Jin et al. / Microporous and Mesoporous Materials 97 (2006) 141–144
tion temperature and reactants ratio; the results show a diversity of single crystal like morphologies. Crystal like mesoporous silica SBA-16 with decaoctahedron and rhomb-dodecahedron shape is obtained. The typical synthetic condition is 1.00TEOS:0.0041F127:5.00HCl:180H2O at 28 °C for decaoctahedron shape, and 1.00TEOS: 0.0053F127:4.10HCl:150H2O at 32 °C for rhomb-dodecahedron shape. Acknowledgements
Fig. 4. Effect of hydrothermal treatment: the decaoctahedron shape like SBA-16.
The synthetic conditions should be carefully controlled in order to obtain high yield of the ‘‘target’’ crystal. Lower surfactant concentration could not lead to meosporous silica, and higher concentration would not promote the surfactant/silicates condensation. Mildly acidic conditions (1.2–1.7 M HCl) and a moderate reaction temperature (26–34 °C) were necessary for the syntheses. Stronger acidity or higher temperature would promote a rapid, uncontrolled hydrolysis/condensation of silica species that would not lead to the formation of crystals with a regular morphology. Weaker acidity with an HCl concentration less than 1.2 M would lead to the formation of other mesoporous structure [26], and lower reaction temperature would result in materials with amorphous morphology and poorly ordered mesostructures. For instance, a relatively lower F127 concentration and reaction temperature favors the formation of decaoctahedral shape, while higher F127 concentration and higher reaction temperature proves rhomb-dodecahedron shape. In general, the hydrothermal treatment would improve the silicates condensation, the stability of the mesoporous materials and enlarge the pore size. But in the crystal like morphology synthesis, further hydrothermal treatment of the powder with mother solution is not recommended. Complete condensation of the silicates in the solution through hydrothermal treatment would not derive SBA16 with good crystal morphology. For example, in the decaoctahedron shape like SBA-16 synthesis, small spheres other than crystals would form on the surface of the crystals after the sample was hydrothermal treated at 100 °C for 72 h (Fig. 4). As shown in a recent publication [18], the evolution of spheres was likely due to the degradation of the surfactant.
The authors acknowledge the financial support of the State Basic Research Project of China (G200077507), the National Natural Science Foundation of China (Grant Nos. 20233030, 20271045), and the State Key Laboratory of Inorganic Synthesis and Preparative Chemistry of Jilin University. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24]
4. Conclusions In this study, a simple synthesis of SBA-16 crystals under static was carried out by merely control of the reac-
[25] [26]
M. Antonietti, G.A. Ozin, Chem. Eur. J. 10 (2004) 28. H. Co¨lfen, S. Mann, Angew. Chem. Int. Ed. 42 (2003) 2350. E. Dujardin, S. Mann, Angew. Chem. Int. Ed. 13 (2002) 775. P. Schmidt-Winkel, P. Yang, D.I. Margolese, B.F. Chmelka, G.D. Stucky, Adv. Mater. 11 (1999) 303. H.-P. Lin, C.-Y. Mou, Acc. Chem. Res. 35 (2002) 927. B.-H. Han, W. Zhou, A. Sayari, J. Am. Chem. Soc. 125 (2003) 3444. A. Sayari, B.-H. Han, Y. Yang, J. Am. Chem. Soc. 126 (2004) 14348. S.K. Kim, R. Ryoo, Chem. Commun. 2 (1998) 259. M. Kaneda, T. Tsubakiyama, A. Carlsson, Y. Sakamoto, T. Ohsuna, O. Terasaki, J. Phys. Chem. B 106 (2002) 1256. S. Che, Y. Sakamoto, O. Terasaki, T. Tatsumi, Chem. Mater. 13 (2001) 2237. M.-C. Chao, D.-S. Wang, H.-P. Lin, C.-Y. Mou, J. Mater. Chem. 13 (2003) 2853. Y. Sakamoto, M. Kneda, O. Terasaki, D. Zhao, J.M. Kim, G.D. Stucky, H.J. Shin, R. Ryoo, Nature 408 (2000) 449. S. Che, S. Lim, M. Kneda, H. Yoshitake, O. Terasaki, T. Tatsumi, J. Am. Chem. Soc. 124 (2002) 13962. J. Wang, C.K. Tsung, Y. Wu, G.D. Stucky, Angew. Chem. Int. Ed. 44 (2005) 332. C. Yu, B. Tian, J. Fan, G.D. Stucky, D. Zhao, J. Am. Chem. Soc. 124 (2002) 4556. C. Yu, B. Tian, J. Fan, D. Zhao, Chem. Mater. 16 (2004) 880. Y.K. Hwang, J.S. Chang, Y.U. Kwon, S.E. Park, Micropor. Mesopor. Mater. 68 (2004) 21. M. Mesa, L. Sierra, J. Patarin, J.L. Guth, Solid State Sci. 990 (2005) 7. L. Sierra, M. Mesa, A. Ramirez, B. Lopez, J.L. Guth, Stud. Surf. Sci. Catal. Part A–C 573 (2004) 154. S. Guan, S. Iagaki, T. Ohsuna, O. Terasaki, J. Am. Chem. Soc. 122 (2000) 5660. P.N. Trikalitis, N. Ding, C. Malliakas, S.J.L. Billinge, M.G. Kanatzidis, J. Am. Chem. Soc. 126 (2004) 15326. P.N. Trikalitis, K.K. Rangan, T. Bakas, M.G. Kanatzidis, J. Am. Chem. Soc. 124 (2002) 12255. F. Kleitz, L.A. Solovyov, G.A. Anikumar, S.H. Choi, R. Ryoo, Chem. Commun. 13 (2004) 1536. J.Y. Ying, C.P. Mehnert, M.S. Wong, Angew. Chem. Int. Ed. 38 (1999) 56. J. Patarin, B. Lebeau, R. Zana, Curr. Opin. Colloid Interface Sci. 7 (2002) 107. F. Kleitz, D. Liu, G.M. Anikumar, I.-S. Park, L.A. Solovyov, A.N. Shmakov, R. Ryoo, J. Phys. Chem. B 107 (2003) 14926.