Fabrication and photocatalytic activity of Ag₃PO₄-TiO₂ heterostructural nanotube arrays

Abstract

To extend the absorption capability of TiO₂ into visible light region and inhibit the recombination of photogenerated electrons and holes, we put forward an effective strategy of the coupling of TiO₂ with a suitable semiconductor that possesses a narrow band gap. Meanwhile, Ag₃PO₄-TiO₂ heterostructural nanotube arrays were prepared by the two-step anodic oxidation to obtain the TiO₂ nanotube arrays and then by a deposition-precipitation method to load Ag₃PO₄. The samples were characterized by field emission scanning electron microscopy (FESEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The experimental results showed that Ag₃PO₄ nanoparticles were uniformly dispersed on the highly ordered TiO₂ nanotube arrays, which increased the visible-light absorption of TiO₂ photocatalyst. The photocurrent density and photocatalytic degradation of methyl orange indicated that the performance of Ag₃PO₄-TiO₂ heterostructural nanotube arrays was better than that of the TiO₂ nanotube arrays, which could be attributed to the effective electron-hole separation and the improved utilization of visible light.

Keywords

Ag₃PO₄-TiO₂ nanotube arrays / anodic oxidation / heterostructure / photocatalysis

References

[1] Wang P, Wang J, Ming TS, et al. Dye-sensitization-induced Visible-light Reduction of Graphene Oxide for the Enhanced TiO₂ Photocatalytic Performance[J]. ACS Appl. Mater. Interface, 2013, 5: 2924-2929.

[2] Yin SM, Yang M, Yan YW. Preparation of V-doped TiO₂ Photocatalysts by the Solution Combustion Method and Their Visible Light Photocatalysis Activities[J]. J. Wuhan Univ. Technol. -Mater. Sci. Ed., 2014, 36: 5863-868.

[3] Zhang QH, an X, Shao R, et al. Preparation of Nano-TiO₂ by Liquid Hydrolysis and Characterization of Its Antibacterial Activity[J]. J. Wuhan Univ. Technol. -Mater. Sci. Ed., 2014, 36: 2407-409.

[4] Albu SP, Kim D, Schmuki P. Growth of Aligned TiO₂ Bamboo-type Nanotubes and Highly Ordered Nanolace[J]. Angew. Chem., 2008, 120: 101942-1945.

[5] Macák JM, Tsuchiya H, Schmuki P. High-aspect-ratio TiO₂ Nanotubes by Anodization of Titanium[J]. Angew. Chem., 2005, 44: 142100-2102.

[6] Guan DS, Hymel PJ, Wang Y. Growth Mechanism and Morphology Control of Double-layer and Bamboo-type TiO₂ Nanotube Arrays by Aanodic Oxidation[J]. Electrochimica Acta, 2012, 83: 0420-429.

[7] Lin J, Guo M, Yip CT, et al. High Temperature Crystallization of Freestanding Anatase TiO₂ Nanotube Membranes for High Efficiency Dyesensitized Solar Cells[J]. Adv. Funct. Mater., 2013, 23: 475952-5960.

[8] Shrestha NK, Macak JM, Schmidt-Stein F, et al. Magnetically Guided Titania Nanotubes for Site-selective Photocatalysis and Drug Release[J]. Angew. Chem., 2009, 48: 5969-972.

[9] Liu N, Lee K, Schmuki P. Reliable Metal Deposition into TiO₂ Nanotubes for Leakage-free Interdigitated Electrode Structures and Use as a Memristive Electrode[J]. Angew. Chem., 2013, 52: 4712381-12384.

[10] Lee K, Hahn R, Altomare M, et al. Intrinsic Au Decoration of Growing TiO₂ Nanotubes and Formation of a High-efficiency Photocatalyst for H₂ Production[J]. Adv. Mater., 2013, 25: 426133-426137.

[11] Li XH, Chen GY, Yang LB, et al. Multifunctional Au-coated TiO₂ Nanotube Arrays as Recyclable SERS Substrates for Multifold Organic Pollutants Detection[J]. Adv. Funct. Mater., 2010, 20: 172815-172824.

[12] Fujishima A, Zhang XT, Tryk DA. TiO₂ Photocatalysis and Related Surface Phenomena[J]. Surf. Sci. Rep., 2008, 63: 12515-12582.

[13] Wang P, Wang J, Wang XF, et al. One-step Synthesis of Easy-recycling TiO₂-rGO Nanocomposite Photocatalysts with Enhanced Photocatalytic Activity[J]. Appl. Catal. B: Environ., 2013, 132-133: 452-459.

[14] Zhao ZG, Liu ZF, Miyauchi M. Nature-inspired Construction, Characterization, and Photocatalytic Properties of Single-crystalline Tungsten Oxide Octahedra[J]. Chem. Comm., 2010, 46: 193321-3323.

[15] Li GL, Liang W, Xue JB, et al. Electrochemical Preparation and Photoelectric Properties of Cu₂O-loaded TiO₂ Nanotube Arrays [J]. J. Wuhan Univ. Technol. -Mater. Sci. Ed., 2014, 36: 23-28.

[16] Yi ZG, Ye JH, Kikugawa N, et al. An Orthophosphate Semiconductor with Photooxidation Properties under Visible-light Iirradiation[J]. Nat. Mater., 2010, 9: 7559-7564.

[17] Bi YP, Ouyang SX, Cao JY, et al. Facile Synthesis of Rhombic Dodecahedral AgX/Ag3PO₄ (X = Cl, Br, I) Heterocrystals with Enhanced Photocatalytic Properties and Stabilities[J]. Phys. Chem. Chem. Phys., 2011, 13: 2110071-2110075.

[18] Bi YP, Hu HY, Ouyang SX, et al. Photocatalytic and Photoelectric Properties of Cubic Ag₃PO₄ Sub-microcrystals with Sharp Corners and Edges[J]. Chem. Comm., 2012, 48: 313748-313750.

[19] Yu HG, Cao GQ, Chen F, et al. Enhanced Photocatalytic Performance of Ag₃PO₄ by Simultaneous Loading of Ag nanoparticles and Fe(III) Cocatalyst[J]. Appl. Catal. B: Environ., 2014, 160-161: 0658-665.

[20] Ma XG, Lu B, Li D, et al. Origin of Photocatalytic Activation of Silver Orthophosphate from Ffirst-principles[J]. J. Phys. Chem. C, 2011, 115: 114680-114687.

[21] Umezawa N, Ouyang SX, Ye JH. Theoretical Study of High Photocatalytic Performance of Ag₃PO₄[J]. Phys. Rev. B, 2011, 83(3): 79-83.

[22] Yu HG, Liu R, Wang XF, et al. Enhanced Visible-light Photocatalytic Activity of Bi₂WO₆ Nanoparticles by Ag₂O Cocatalyst[J]. Appl. Catal. B: Environ., 2012, 111-112: 0326-333.

[23] Yu HG, Liu L, Wang XF, et al. The Dependence of Photocatalytic Activity and Photoinduced Self-stability of Photosensitive AgI Nanoparticles[J]. Dalton Trans., 2012, 41(34): 10405-10411.

[24] Serpone N, Maruthamuthu P, Pichat P, et al. Exploiting the Interparticle Electron Transfer Process in the Photocatalysed Oxidation of Phenol, 2-chlorophenol and Ppentachlorophenol: Chemical Evidence for Electron and Hole Transfer between Coupled Semiconductors[J]. J. Photochem. and Photobiol. A, 1995, 85: 3247-3255.