Self-assembly of Ag-TiO₂ nanoparticles: Synthesis, characterization and catalytic application

Abstract

The formation of Ag clusters on titanium oxide (TiO₂) nanoparticles was achieved by selfassembly process and calcination. The obtained nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and ultraviolet visible spectroscopy (UV-Vis), and conventional techniques (XRD, TEM and UV-Vis) were used to identify Ag particles on the TiO₂ surfaces. The results show that Ag-TiO₂ particles can be applied to improve catalytic activity of the epoxidation of styrene oxides. Styrene oxide is the main product of catalytic reaction with H₂O₂ as the oxidant by using Ag-TiO₂ nanoparticles as catalysts. High catalytic activitity of styrene oxide can be obtainable at 80 °C. The reaction temperature, reaction time, the molar ratio of H₂O₂/styrene and solvent affect greatly the catalytic epoxidation of styrene.

Keywords

self-assembly / Ag-TiO₂ nanoparticles / catalysis

References

[1] Iliev V., Tomova D., Bilyarska L., . Influence of the Size of Gold Nanoparticles Deposited on TiO₂ upon the Photocatalytic Destruction of Oxalic Acid[J]. J. Mol. Catal. A: Chem., 2007, 263(1–2): 32-38.

[2] Sankapal B. R., Sartale S. D., Lux-Steiner C., . Chemical and Electrochemical Synthesis of Nanosized TiO₂ Anatase for Large-area Photon Conversion[J]. C. R. Chimie, 2006, 9(5–6): 702-707.

[3] Xie M. Z., Jing L. Q., Zhou J., . Synthesis of Nanocrystalline Anatase TiO₂ by One-pot Two-phase Separated Hydrolysis-solvothermal Processes and Its High Activity for Photocatalytic Degradation of Rhodamine B[J]. J. Hazard. Mater., 2010, 176(1–3): 139-145.

[4] Ohsaka T., Shinozaki K., Tsuruta T., . Photo-electrochemical Degradation of Some Chlorinated Organic Compounds on N-TiO₂ Electrode[J]. Chemosphere, 2008, 73(81): 279-1 283.

[5] Su C. C., Liao C. H., Wang J. D., . The Adsorption and Reactions of Methyl Iodide on Powdered Ag/TiO₂[J]. Catal. Today, 2004, 97(1): 71-79.

[6] Kwon C. H., Kim J. H., Jung I. S., . Preparation and Characterization of TiO₂-SiO₂ Nano-composite Thin Films[J]. Ceram. Int., 2003, 29(8): 851-856.

[7] Sharmaa G. D., Suresha P., Sharmaa S. K., . Optical and Electrical Properties of Hybrid Photovoltaic Devices from Poly (3-phenyl hydrazone thiophene) (PPHT) and TiO₂ Blend Films[J]. Sol. Energ. Mat. Sol. C, 2008, 92(1): 61-70.

[8] Kim Y. H., Kim C. W., Cha H. G., . Bulklike Thermal Behavior of Antibacterial Ag-SiO₂ Nanocomposites[J]. J. Phys. Chem. C, 2009, 113(13): 5 105-5 110.

[9] Du J. M., Zhang J. L., Liu Z. M., . Controlled Synthesis of Ag/TiO₂ Core-shell Nanowires with Smooth and Bristled Surfaces via a Onestep Solution Route[J]. Langmuir, 2006, 22(3): 1 307-1 312.

[10] Ghosh R., Shen X. F., Villegas J. C., . Role of Manganese Oxide Octahedral Molecular Sieves in Styrene Epoxidation[J]. J. Phys. Chem. B, 2006, 110(14): 7 592-7 599.

[11] Espinal L., Suib S. L., Rusling J. F. Electrochemical Catalysis of Styrene Epoxidation with Films of MnO₂ Nanoparticles and H₂O₂[J]. J. Am. Chem. Soc., 2004, 126(14): 7 676-7 682.

[12] Klust A., Madix R. J. Selectivity Limitations in the Heterogeneous Epoxidation of Olefins: Branching Reactions of the Oxametallacycle Intermediate in the Partial Oxidation of Styrene[J]. J. Am. Chem. Soc., 2006, 128(4): 1 034-1 035.

[13] Zhou L., Gorin C. F., Madix R. J. Cesium Promotion in Styrene Epoxidation on Silver Catalysts[J]. J. Am. Chem. Soc., 2010, 132(2): 434-435.

[14] Chimentão R. J., Medina F., Fierro J. L. G., . Propene Epoxidation by Nitrous Oxide over Au-Cu/TiO₂ Alloy Catalysts[J]. J. Mol. Catal. A: Chem., 2007, 274(1–2): 159-168.

[15] Lignier P., Mangematin S., Morfin F., . Solvent and Oxidant Effects on the Au/TiO₂-catalyzed Aerobic Epoxidation of Stilbene[J]. Catal. Today, 2008, 138(1–2): 50-54.

[16] Liu X. H., Kan C., Wang X., . Self-assembled Nanodisks with Targetlike Multirings Aggregated at the Air-water Interface[J]. J. Am. Chem. Soc., 2006, 128(1): 430-431.

[17] Kan C., Liu X. H., Wang X., . Effects of Different Anionic Surfactant Templates (H⁺A⁻, Na⁺A⁻) on Titanium Self-assembly: In the Air-water Interfacial Films[J]. Colloid. Surface A: Physicochem. Eng. Aspects, 2007, 311(1–3): 93-98.

[18] Weibel J. M., Blanc A., Pale P. Ag-mediated Reactions: Coupling and Heterocyclization Reactions[J]. Chem. Rev., 2008, 108(8): 3 149-3 150.

[19] Brook L. A., Evans P., Foster H. A., . Highly Bioactive Silver and Silver/titania Composite Films Grown by Chemical Vapour Deposition[J]. J. Photochem. Photobiol. A: Chem., 2007, 187(1): 53-63.

[20] Wang J., Zhao G., Zhang Z. H., . Investigation on Degradation of Azo Fuchsine Using Visible Light in the Presence of Heat-treated Anatase TiO₂ Powder[J]. Dyes and Pigments, 2007, 75(2): 335-343.

[21] Water L. G. A. V., Bergwerff J. A., Alexander-Nijhuis T., . UV-Vis Microspectroscopy: Probing the Initial Stages of Supported Metal Oxide Catalyst Preparation[J]. J. Am. Chem. Soc., 2005, 127(14): 5 024-5 025.

[22] Yu D., Yam V. W. W. Controlled Synthesis of Monodisperse Silver Nanocubes in Water[J]. J. Am. Chem. Soc., 2004, 126(41): 13 200-13 201.