101
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Li G, Bai R, Zhao XS. Coating of TiO2 Thin Films on the Surface of SiO2 Microspheres: Toward Industrial Photocatalysis. Ind Eng Chem Res 2008. [DOI: 10.1021/ie800561y] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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102
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Li Q, Jonas U, Zhao XS, Kappl M. The forces at work in colloidal self-assembly: a review on fundamental interactions between colloidal particles. ASIA-PAC J CHEM ENG 2008. [DOI: 10.1002/apj.144] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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103
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Bai P, Wu P, Zhao G, Yan Z, Zhao XS. Cation–anion double hydrolysis derived mesoporous γ-Al2O3as an environmentally friendly and efficient aldol reaction catalyst. ACTA ACUST UNITED AC 2008. [DOI: 10.1039/b713283b] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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104
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She XL, Song GJ, Peng Z, Li JJ, Lim CT, Tan EPS, Lv L, Zhao XS. Nanocables Prepared from Polyamide 66 nanotubes Enveloping Pt nanowires by a Secondary-template Method. Polym J 2007. [DOI: 10.1295/polymj.pj2007008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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105
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Bao XY, Li X, Zhao XS. Synthesis of large-pore methylene-bridged periodic mesoporous organosilicas and its implications. J Phys Chem B 2007; 110:2656-61. [PMID: 16471868 DOI: 10.1021/jp0561120] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this article, we report the synthesis of methylene-bridged periodic mesoporous organosilicas (PMOs) of the SBA-15 type. The materials were characterized by SAXS, BET, NMR, FESEM, and TEM. It was found that the synthesis of methylene-bridged SBA-15 PMOs requires more rigorous conditions than that of SBA-15 PMOs bearing organic bridges other than methylene. A mild acidic environment, which slows down the hydrolysis and condensation rates of the precursor, with the assistance of a salt, which enhances precursor-template interaction, should be used to synthesize high-quality large-pore methylene-bridged PMOs. We attributed this to the fast hydrolysis and condensation rates and the rigid backbone of precursor 1,2-bis(triethoxysilyl)methylene. By examining and comparing the synthesis of three large-pore PMOs with different bridges, we concluded that the inductive, bridging, and conformation effects of the organic bridging group play an important role in the synthesis of large-pore PMO materials.
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106
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Zhou J, Takeuchi M, Ray AK, Anpo M, Zhao XS. Enhancement of photocatalytic activity of P25 TiO2 by vanadium-ion implantation under visible light irradiation. J Colloid Interface Sci 2007; 311:497-501. [PMID: 17416386 DOI: 10.1016/j.jcis.2007.03.007] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 03/01/2007] [Accepted: 03/02/2007] [Indexed: 11/18/2022]
Abstract
An ion-implantation method was used to prepare V-ion-implanted P25 TiO2 photocatalysts. Their photocatalytic activity for the degradation of formic acid under visible light irradiation (lambda>450 nm) was investigated. Upon implantation of V ions into the lattice of P25 TiO2, the photoactivity was remarkably enhanced. HRTEM images showed that the implanted V ions existed in the form of VO2(T) in the lattice of P25 TiO2. The intensity of photoluminescence (PL) spectra of V-ion-implanted P25 TiO2 decreased with the increase of the amount of implanted V ions, indicating the decrease of electron-hole pair recombination. It was also observed that the lower the PL intensity of V-ion-implanted P25 TiO2, the higher the photoactivity.
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107
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Bai P, Su F, Wu P, Wang L, Lee FY, Lv L, Yan ZF, Zhao XS. Copolymer-controlled homogeneous precipitation for the synthesis of porous microfibers of alumina. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:4599-605. [PMID: 17335261 DOI: 10.1021/la0634185] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Mesoporous aluminas with a uniform fibrous morphology were synthesized using a copolymer-controlled homogeneous precipitation method under hydrothermal conditions. Scanning electron microscopy, X-ray diffraction, solid-state magic-angle spinning nuclear magnetic resonance, transmission electron microscopy, thermogravimetric analysis, nitrogen adsorption, Fourier transform infrared spectrometry, and elemental analysis techniques were used to characterize the samples. The effect of various synthesis conditions on the morphology and mesoporous structure of the alumina fibers was investigated. Such porous alumina microfibers may find applications in nanotechnology and catalysis. They can also be used as advanced high-temperature composite materials and templates for fabrication of fibrous materials of various compositions, such as carbon, transition-metal oxides, and polymers.
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108
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Zhang WM, Zhang QJ, Pan BC, Lv L, Pan BJ, Xu ZW, Zhang QX, Zhao XS, Du W, Zhang QR. Modeling synergistic adsorption of phenol/aniline mixtures in the aqueous phase onto porous polymer adsorbents. J Colloid Interface Sci 2007; 306:216-21. [PMID: 17118387 DOI: 10.1016/j.jcis.2006.10.056] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2006] [Revised: 10/20/2006] [Accepted: 10/20/2006] [Indexed: 11/26/2022]
Abstract
The adsorption equilibria of phenol and aniline on nonpolar polymer adsorbents (NDA-100, XAD-4, NDA-16 and NDA-1800) were investigated in single- and binary-solute adsorption systems at 313 K. The results showed that all the adsorption isotherms of phenol and aniline on these adsorbents can be well fitted by Freundlich and Langmuir equations, and the experimental uptake of phenol and aniline in all binary-component systems is obviously higher than predicted by the extended Langmuir model, arising presumably from the synergistic effect caused by the laterally acid-base interaction between the adsorbed phenol and aniline molecules. A new model (MELM) was developed to quantitatively describe the synergistic adsorption behavior of phenol/aniline equimolar mixtures in the binary-solute systems and showed a marked improvement in correlating the binary-solute adsorption of phenol and aniline by comparison with the widely used extended Langmuir model. The newly developed model confirms that the synergistic coefficient of one adsorbate is linearly correlated with the adsorbed amount of the other, and the larger average pore size of adsorbent results in the greater synergistic effect of phenol/aniline equimolar mixtures adsorption.
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109
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Zhou Z, Yan Q, Li Q, Zhao XS. Fabrication of binary colloidal crystals and non-close-packed structures by a sequential self-assembly method. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:1473-7. [PMID: 17241075 DOI: 10.1021/la062601v] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Binary colloidal films of polystyrene (PS) spheres and silica spheres were fabricated with a sequential growth method using differently sized colloidal particles. In particular, we demonstrate the structures formed by a silica monolayer growing on top of a PS monolayer and a silica multilayer growing on top of a PS monolayer. By removal of the bottom PS layers, non-close-packed hexagonal, pentagonal, and square silica arrays were obtained at the original silica/PS interface. The possible formation mechanism of the non-close-packed structure was discussed, which may be used to explain how 3D colloidal crystals grow on patterned substrates.
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110
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Zhou J, Zou Z, Ray AK, Zhao XS. Preparation and Characterization of Polycrystalline Bismuth Titanate Bi12TiO20 and Its Photocatalytic Properties under Visible Light Irradiation. Ind Eng Chem Res 2007. [DOI: 10.1021/ie0613220] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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111
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Lv L, Wang K, Zhao XS. Effect of operating conditions on the removal of Pb2+ by microporous titanosilicate ETS-10 in a fixed-bed column. J Colloid Interface Sci 2007; 305:218-25. [PMID: 17045285 DOI: 10.1016/j.jcis.2006.09.053] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Revised: 09/18/2006] [Accepted: 09/21/2006] [Indexed: 11/17/2022]
Abstract
The breakthrough behavior of Pb2+ in an ETS-10 fixed bed was experimentally examined at various operating conditions. Results showed that the adsorption amount of Pb2+ ions per unit mass of ETS-10 particles in a column is about 1.68 mmol/g under the experimental conditions. This amount was not markedly affected by the operating conditions because of the rapid adsorption rate of Pb2+ ions on ETS-10. In the presence of competitive metal ions, the amount of Pb2+ adsorbed on ETS-10 was slightly reduced. An overshoot of the effluent concentrations of competitive metal ions Cu2+ and Cd2+ was observed in the adsorption systems of binary and ternary solutions. This is ascribed to the replacement of pre-adsorbed Cu2+ and Cd2+ ions by Pb2+ ions. The ETS-10 column broken up by Pb2+ ions can be regenerated by using an EDTA-Na2 solution and the regenerated column can be reused.
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112
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Yan Q, Zhao XS, Teng JH, Chua SJ. Colloidal woodpile structure: three-dimensional photonic crystal with a dual periodicity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:7001-6. [PMID: 16863251 DOI: 10.1021/la060808i] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
With planar photolithography and self-assembly techniques, multilayer colloidal crystals with a woodpile structure were fabricated. They represent a new kind of photonic crystals, that is, three-dimensional (3D) photonic crystals with a dual periodicity; one comes from the face-centered cubic (fcc) structure within the colloidal crystal strips and the other one results from the periodic arrangement of the colloidal crystal strips.
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113
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Yan Q, Chen A, Chua SJ, Zhao XS. Nanosphere lithography from template-directed colloidal sphere assemblies. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2006; 6:1815-8. [PMID: 17025090 DOI: 10.1166/jnn.2006.227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Conventional nanosphere lithography holds the drawbacks of lacking precise control over the shape and architecture of the resultant nanostructures. In this work, nanoimprinting lithography was used to construct various desired patterns on a polymer film coated on a silicon substrate. The patterns were then used as templates to direct the self-assembly of silica colloidal spheres, forming colloidal assemblies with well-controlled sizes, shapes, and structures. Subsequent nanosphere lithography using template-directed colloidal sphere assemblies resulted in complex nanostructures that can not be obtained using the conventional nanosphere lithography method.
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114
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Zhou J, Zhang Y, Zhao XS, Ray AK. Photodegradation of Benzoic Acid over Metal-Doped TiO2. Ind Eng Chem Res 2006. [DOI: 10.1021/ie051098z] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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115
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Li G, Zhao XS. Characterization and Photocatalytic Properties of Titanium-Containing Mesoporous SBA-15. Ind Eng Chem Res 2006. [DOI: 10.1021/ie0514253] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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116
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Zhou Z, Li Q, Zhao XS. Evolution of interparticle capillary forces during drying of colloidal crystals. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:3692-7. [PMID: 16584244 DOI: 10.1021/la052934c] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Photonic crystals are periodic structures that have the capability to manipulate the photons in the same way as semiconductors do for electrons. The self-assembly strategy that utilizes colloidal crystals as a template to form photonic crystals has received a great deal of recent research interest because it is simple and cost-effective. Experimental studies and theoretical analysis have speculated that capillary forces play a pivotal role in forming the colloidal crystals during the crystal growth process and that particularly during the drying stage the changing of the magnitude of capillary forces is critical to the resultant microstructure. This paper presents a computational analysis of the changing capillary forces, which may throw light on a refined strategy for controlling colloidal crystal growth.
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117
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Wang L, Yan Q, Zhao XS. From planar defect in opal to planar defect in inverse opal. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:3481-4. [PMID: 16584215 DOI: 10.1021/la053470l] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We demonstrate a facile method of fabricating opal and inverse opal structures with a planar defect. A single layer of silica beads was embedded into polystyrene opals by combining an inward-growing self-assembly method with spin-coating technique. After the infiltration of silica followed by the removal of the polystyrene beads by calcination, an inverted structure was obtained. The silica beads were connected together by the infiltrated silica, thus a solid silica phase with the silica beads as a planar defect embedded in the inverse silica opal was obtained. The thickness of the defect layer can be adjusted by changing the size of the silica beads. Scanning electron microscope images showed the good quality of the crystal and the uniformity of the defect layer. Optical transmission spectra indicated the existence of a defect state induced by the defect layer in both the opal and inverse opal structures. High-cost techniques such as lithography and chemical vapor deposition are not involved in the fabrication of inverse opals with planar defects.
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118
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Zhao XS, Su F, Yan Q, Guo W, Bao XY, Lv L, Zhou Z. Templating methods for preparation of porous structures. ACTA ACUST UNITED AC 2006. [DOI: 10.1039/b513060c] [Citation(s) in RCA: 171] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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119
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Wang L, Yan Q, Zhao XS. Fabrication of free-standing non-close-packed opal films. ACTA ACUST UNITED AC 2006. [DOI: 10.1039/b611013d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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120
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Yan Q, Liu F, Wang L, Lee JY, Zhao XS. Drilling nanoholes in colloidal spheres by selective etching. ACTA ACUST UNITED AC 2006. [DOI: 10.1039/b604463h] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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121
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Su F, Zhao XS, Wang Y, Wang L, Lee JY. Hollow carbon spheres with a controllable shell structure. ACTA ACUST UNITED AC 2006. [DOI: 10.1039/b609971h] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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122
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Su F, Zhao XS, Wang Y, Zeng J, Zhou Z, Lee JY. Synthesis of Graphitic Ordered Macroporous Carbon with a Three-Dimensional Interconnected Pore Structure for Electrochemical Applications. J Phys Chem B 2005; 109:20200-6. [PMID: 16853611 DOI: 10.1021/jp0541967] [Citation(s) in RCA: 183] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, ordered macroporous carbon with a three-dimensional (3D) interconnected pore structure and a graphitic pore wall was prepared by chemical vapor deposition (CVD) of benzene using inverse silica opal as the template. Field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectrometry, nitrogen adsorption, and thermogravimetric analysis techniques were used to characterize the carbon samples. The electrochemical properties of the carbon materials as a carbon-based anode for lithium-ion batteries and as a Pt catalyst support for room-temperature methanol electrochemical oxidation were examined. It was observed that the CVD method is a simple route to fabrication of desired carbon nanostructures, affording a carbon with graphitic pore walls and uniform pores. The graphitic nature of the carbon enhances the rate performance and cyclability in lithium-ion batteries. The specific capacity was found to be further improved when SnO(2) nanoparticles were supported on the carbon. The specific activity of Pt catalyst supported on the carbon materials for room-temperature methanol electrochemical oxidation was observed to be higher than that of a commercial Pt catalyst (E-TEK).
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123
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Lv L, Hor MP, Su F, Zhao XS. Competitive adsorption of Pb2+, Cu2+, and Cd2+ ions on microporous titanosilicate ETS-10. J Colloid Interface Sci 2005; 287:178-84. [PMID: 15914164 DOI: 10.1016/j.jcis.2005.01.073] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Revised: 01/14/2005] [Accepted: 01/24/2005] [Indexed: 10/25/2022]
Abstract
In the present study, the competitive adsorption characteristics of binary and ternary heavy metal ions Pb2+, Cu2+, and Cd2+ on microporous titanosilicate ETS-10 were investigated in batch systems. Pure microporous titanosilicate ETS-10 was synthesized with P25 as the Ti source and characterized by the techniques of X-ray diffraction (XRD), field emission-scanning electron microscope (FESEM), nitrogen adsorption, and zeta-potential. Equilibrium and kinetic adsorption data showed that ETS-10 displays a high selectivity toward one metal in a two-component or a three-component system with an affinity order of Pb2+ > Cd2+ > Cu2+. The equilibrium behaviors of heavy metals species with stronger affinity toward ETS-10 can be described by the Langmuir equation while the adsorption kinetics of the metals can be well fitted to a pseudo-second-order (PSO) model.
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124
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Zhou Z, Zhao XS. Opal and inverse opal fabricated with a flow-controlled vertical deposition method. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:4717-23. [PMID: 16032895 DOI: 10.1021/la046775t] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In this work, an improved vertical deposition method, namely, a flow-controlled vertical deposition (FCVD) method, was used to grow colloidal crystals with large spherical colloids in water solvent and to infiltrate the colloidal crystals. Using the FCVD method, latex spheres as large as 2 microm can be fabricated into colloidal crystals in water. In addition, the method works very well for controlling surface morphologies of silica-infiltrated opals. Furthermore, fabrication of colloidal crystal heterostructures was demonstrated.
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125
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Bao XY, Zhao XS. Morphologies of Large-Pore Periodic Mesoporous Organosilicas. J Phys Chem B 2005; 109:10727-36. [PMID: 16852303 DOI: 10.1021/jp050449k] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this article, we report a systematic investigation on the morphologies of SBA-15 type large-pore periodic mesoporous organosilicas templated by the block copolymer P123. By tuning synthetic parameters such as stirring, acidity, reaction ratio, reaction duration, and autoclaving, a wide spectrum of unique primary particle morphologies, such as the spindle-, pearl-, diamond-, rod-, and platelike particles, and nanoparticles has been prepared. These primary particles were found to self-assemble in solution to form various large hierarchical macrostructures, such as mesostructured necklaces and cobweb-supported necklaces. The assembling process was elucidated with the information observed at different stages of reaction. Stirring, reaction duration, and autoclaving were identified to be the key factors affecting the efficiency and degree of the self-assembly process. A nucleation-accretion mechanism for the formation of various PMO primary particles was proposed by examining the relation between the external morphologies and the underlying mesostructure.
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