Preparation, characterization and photocatalytic property of Ag-loaded TiO₂ powders using photodeposition method

Abstract

The Ag particles were photodeposited on TiO₂ powder surface. The X-ray diffraction (XRD), Raman spectroscopy, transmittance electron microscopy (TEM), UV-vis diffused reflection spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectrophotoscopy were used to investigate the structure and morphologies of the samples. It is found that the loaded Ag particles have no effect on the XRD patterns, and the Raman scattering becomes much stronger due to the surface Raman enhancing effect. The TEM images show that the TiO₂ grains are in the shape of short sticks, and the spherical Ag particles with hexagonal structure are adhered to the TiO₂ grain surface tightly. XPS result shows that the loaded Ag particles can not affect the chemical states of Ti and O, and they are mainly in the form of metal Ag. A wide plasmon absorption appears on the UV-vis spectra after Ag photodeposition. The loaded Ag further greatly decreases the PL intensity, which partly indicates the electron transfer from TiO₂ to Ag. The photocatalytic activities firstly increase with the content of loaded Ag, and then sharply decrease. Finally, the photocatalytic mechanism related to Ag-loaded TiO₂ powders was discussed in detail.

Keywords

Ag-TiO₂ / photodeposition / photocatalysis

References

[1] Mills A., Hunte S. L. An Overview of Semiconductor Photo-catalysis[J]. J. Photochem. Photobio. A: Chem., 1997, 108(1): 1-35.

[2] Linsebigler A. L., Lu G. Q., Yates J. T. Jr Interfacial Photochemistry, Fundamentals and Applications[J]. Chem. Rev., 1995, 95(3): 735-758.

[3] Hoffmann M. R., Martin S. T., Choi W.Y., . Environmental Applications of Semiconductor Photocatalysis[J]. Chem. Rev., 1995, 95(1): 69-96.

[4] Livraghi S., Paganini M. C., Giamello E., . Origin of Photoactivity of N Doped TiO₂ under Visible Light[J]. J. Am. Chem. Soc., 2008, 128(49): 15666-15671.

[5] Yu J. C., Ho W., Yu J., . Efficient Visible-Light-Induced Photocatalytic Disinfection on Sulfur-Doped Nanocrystalline Titania.Environ[J]. Sci. Technol., 2005, 39(4): 1175-1179.

[6] Zhao W., Ma W., Chen C., . Efficient Degradation of Toxic Organic Pollutants with Ni₂O₃/TiO_2−xB_x under Visible Irradiation[J]. J. Am. Chem. Soc., 2004, 126(15): 4782-4783.

[7] Zhu J. F., Chen F., Zhang J. L., . Fe³⁺-TiO² Photocatalysts Prepared by Combining Sol-gel Method with Hydrothermal Treatment and Their Characterization[J]. J. Photochem. Photobio. A: Chem., 2006, 180(1–2): 196-204.

[8] Klosek S., Raftery D. Visible Light Driven V-doped TiO₂ Photocatalyst and its Photooxidation of Ethanol[J]. J. Phys. Chem. B, 2001, 105(14): 2815-2819.

[9] Kesselman J. M., Weres O., Lewis N. S., . Electrochemical Production of Hydroxyl Radical at Polycrystalline Nb-droped TiO₂[J]. J. Phys. Chem. B, 1997, 101(14): 2637-2643.

[10] Zhang W. G., liu Y., wang B., . Preparation of Nano-crystalline TiO₂ Film Modified Ni-W-P Electrode and Its Photoelectrocatalytic Activity for Hydrogen Evolution Reaction[J]. J. Inorg. Mater., 2007, 22(4): 765-768.

[11] Bamwenda G. R., Uesigi T., Abe Y., . The Photocatalytic Oxidation of Water to O₂ over Pure CeO₂, WO₃, and TiO₂ Using Fe³⁺ and Ce⁴⁺ as Electron Acceptors[J]. Appl. Catal., A, 2001, 205(1–2): 117-128.

[12] Yu J. C., Yu J. G., Zhang L. Z., . Enhancing Effects of Water Content and Ultrasonic Irradiation on the Photocatalytic Activity of Nano-sized TiO₂ powders[J]. J. Photochem. Photobio. A: Chem., 2002, 148(1–3): 263-271.

[13] Guin D., Manorama S. V., Latha J. N. L., . Photoreduction of Silver on Bare and Colloidal TiO₂ Nanoparticles/Nanotubes: Synthesis, Characterization, and Tested for Antibacterial Outcome[J]. J. Phys. Chem. C, 2007, 111(36): 13393-13397.

[14] Kikuchi H., Kitano M., Takeuchi M., . Extending the Photoresponce of TiO₂ to the Visible Light Region: Photoelectrochemical Behavior of TiO₂ Thin Films Prepared by the Radio Frequency Magnetron Sputtering Deposition Method[J]. J. Phys. Chem. B, 2006, 110(11): 5537-5541.

[15] Sahyun M. R. V., Serpone N. Primary Events in the Photocatalytic Deposition of Silver on Nanoparticulate TiO₂[J]. Langmuir, 1997, 13(19): 5082-5088.

[16] Chan S. C., Barteau M. A. Preparation of Highly Uniform Ag/TiO₂ and Au/TiO₂ Supported Nanoparticle Catalysts by Photodeposition[J]. Langmuir, 2005, 21(12): 5588-5595.

[17] Bae E. Y., Choi W. Y. Highly Enhanced Photoreductive Degradation of Perchlorinated Compounds on Dye-Sensitized Metal/TiO₂ under Visible Light[J]. Environ. Sci. Technol., 2003, 37(1): 147-152.

[18] Tada H., Ishida T., Takao A., . Drastic Enhancement of TiO₂-Photocatalyzed Reduction of Nitrobenzene by Loading Ag Clusters[J]. Langmuir, 2004, 20(19): 7898-7900.

[19] Hu C., Lan Y. Q., Qu J. H., . Ag/AgBr/TiO₂ Visible Light Photocatalyst for Destruction of Azodyes and Bacteria[J]. J. Phys. Chem. B, 2006, 110(9): 4066-4072.

[20] Grunert W., Bruckner A., Hofmeister H., . Structural Properties of Ag/TiO₂ Catalysts for Acrolein Hydrogenation[J]. J. Phys. Chem. B, 2004, 108(18): 5709-5717.

[21] Hirakawa T., Kamat P. V. Charge Separation and Catalytic Activity of Ag-TiO₂ Core-Shell Composite Clusters under UV-Irradiation[J]. J. Am. Chem. Soc., 2005, 127(11): 3928-3934.

[22] Jin M., Zhang X. T., Nishimoto S., . Light-Stimulated Composition Conversion in TiO₂-Based Nanofibers[J]. J. Phys. Chem. C, 2007, 111(2): 658-665.

[23] Naoi K., Ohko Y., Tatsuma T. TiO₂ Films Loaded with Silver Nanoparticles: Control of Multicolor Photochromic Behavior[J]. J. Am. Chem. Soc., 2004, 126(11): 3664-3668.

[24] Liu B. S., Zhao X. J., Wen L. P. The Structural and Photoluminescence Studies Related to the Surface of the TiO₂ Sol Prepared by Wet Chemical Method[J]. Mater. Sci. Eng. B, 2006, 134(1): 27-31.

[25] Emeline A. V., Ryabchuk V. K., Serpone N. Dogmas and Misconceptions in Heterogeneous Photocatalysis. Some Enlightened Reflections[J]. J. Phys. Chem. B, 2005, 109(39): 18515-18521.

[26] Zhang Q. H., Gao L. Preparation and the Enhanced Photocatalytic Activity of Highly Dispersed Pt Loaded on TiO2 Nanocrystals[J]. Acta Chim. Sinica, 2005, 63(1): 65-70.

[27] Kerker M., Blatchford C. G. Elastic Scattering and Absorption, and Surface-enhanced Raman Scattering by Concentric Spheres Comprised of A Metallic and Dielectric Region[J]. Phys. Rev. B, 1982, 26(8): 4052-4063.

[28] Liu B. S., Zhao X. J., Zhao Q. N., . The Effect of O₂ Partial Pressure on the Structure and Photocatalytic Property of TiO₂ Films Prepared by Sputtering[J]. Mater. Chem. Phys., 2005, 90(1): 207-212.

[29] He X., Zhao X. J., Liu B. S. Studies on A Possible Growth Mechanism of Silver Nanoparticles Loaded on TiO₂ Thin Films by Photoinduced Deposition Method[J]. J. Non-Cryst. Solids, 2008, 354(12–13): 1267-1271.

[30] Liu B. S., Wen L. P., Zhao X. J. The Photoluminescence Spectroscopic Study of Anatase TiO₂ Prepared by Magnetron Sputtering[J]. Materials Chemistry and Physics, 2007, 106(2–3): 350-353.

[31] Miller T. M. Handbook of Chemistry and Physics[M], 1993 80th Ed Washington CRC Press 12

[32] Sadeghi M., Liu W., Zhang T. G., . Role of Photoinduced Charge Carrier Separation Distance in Heterogeneous Photocatalysis: Oxidative Degradation of CH₃OH Vapor in Contact with Pt/TiO₂ and Cofumed TiO₂-Fe₂O₃[J]. J. Phys. Chem., 1996, 100(50): 19466-19474.