Preparation and Characterization of Cu Loaded TiO2 Nanotube Arrays and their Photocatalytic Activity

2011 ◽  
Vol 364 ◽  
pp. 377-381 ◽  
Author(s):  
Syazwani Mohd Zaki ◽  
Srimala Sreekantan

This paper described the preparation of Cu loaded TiO₂ nanotube arrays. Firstly, TiO₂ nanotube arrays were formed by anodization. Afterwards, the formed nanotube arrays were incorporated with Cu by wet impregnation method. The soaking time and concentration were varied to obtain an optimum set of parameter for Cu incorporation in TiO₂ nanotubes. After anodization, all samples were annealed at 400°C for 4 hours to obtain anatase phase. The nanotube arrays were characterized by field emission scanning electron microscopy (FESEM), x-ray diffraction (XRD) and x-ray photoelectron spectra (XPS). An average diameter 63.02 nm and length 12.15µm were obtained for TiO₂ nanotubes. The photocatalytic activity of these nanotubes were investigated with methyl orange (MO) and the TiO₂ nanotube prepared in 0.01M of Cu (NO₃)₂ solution within 3 hours demonstrates the highest photocatalytic activity with 83.6% degradation of methyl orange. Keywords: copper doping, wet impregnation, photocatalytic activity

2014 ◽  
Vol 1024 ◽  
pp. 31-34
Author(s):  
Khairul Arifah Saharudin ◽  
Srimala Sreekantan

In this work, 12 μm titanium oxide (TiO2) nanotube arrays were formed by the anodization of titanium (Ti) foil in ethylene glycol containing 1 wt% water and 5 wt% fluoride for 60 min at 60 V. After annealing at 400 °C in argon for 4 hr, TiO2 nanotube arrays were immersed in 0.02 M phosphoric acid (H3PO4) to incorporate phosphorus (P) into TiO2 nanotube arrays. Results from x-ray photoelectron spectra revealed that the P-incorporated TiO2 nanotubes contained Ti, oxygen (O), P and carbon (C) after wet impregnation process. The photocatalytic activity of the nanotube arrays immersed in H3PO4 at various impregnation times was evaluated by monitoring the degradation of methyl orange. Results indicate that the nanotube immersed in H3PO4 for 90 minutes with an average diameter of 100 nm and an optimal tube length of 12 μm with a thin tube wall (20 nm) is the optimum structure required to achieve high photocatalytic reaction. The incorporated C and P into TiO2 nanotube arrays is believed to provide a shallow trap for photo-generated e- and h+, inhibiting the recombination and extending the lifetime of the charge carriers. Thus, this sample resulted in high degradation of methyl orange as compared with other samples. In addition, the existence of C, P, and high degree of anatase crystallinity, smooth wall and absence of fluoride enhanced the photocatalytic activity of the sample.


2011 ◽  
Vol 197-198 ◽  
pp. 919-925 ◽  
Author(s):  
Min Wang ◽  
Qiong Liu

Silver (Ag+) doped iron (III) vanadate (FeVO4) samples are prepared by the precipitation method and then characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy(XPS). The photocatalytic activity under visible light is evaluated by photocatalytic degradation of methyl orange (MO) in the solution. The results show that both FeVO4 and Ag+ doped FeVO4 samples are triclinic, the later have different surface morphology, and some needle-shaped materials appear in the later. From XPS, there are more Fe2+ ions in Ag+ doped FeVO4 sample than that in FeVO4 one without Ag+. It indicates that Ag+ doping can increase the density of the surface oxygen vacancies of catalysts, which can act as electron traps promoting the electron-hole separation and then increase the photo-activity. The decoloration rate after Ag+ doping against methyl orange solution can reach about 81%, and be more about 20% than that of pure FeVO4.


2012 ◽  
Vol 573-574 ◽  
pp. 110-114 ◽  
Author(s):  
Jin Xia ◽  
Ri Ya Jin ◽  
Kai Xuan Guo ◽  
Si Jing Yang

Titanium dioxide powders were synthesized by ultrasonic-assisted hydrolysis reaction of titanium tetra-isopropoxide at the low-temperature. The samples were characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD). The photocatalytic activity of samples were investigated by the degradation of methyl orange under UV light radiation (6W, λ= 352nm) at room temperature. The results indicated that the products were mainly composed of high homogeneity anatase phases, and the methyl orange degradation rate can reach more than 90% under ultraviolet irradiation 180min. The photocatalytic activity of the samples prepared by ultrasonic method is higher than that of the samples prepared by conventional hydrolysis method.


Author(s):  
Nguyen Quang Long

For a few decades, Titanium Dioxide (TiO2) has been the most studied photocatalyst due to its significant optical property. In the paper, TiO2 pigment powder (Anatase form) was selected as a precursor to prepare a variety of Black-TiO2 samples, and the typical material was then evaluated for its photocatalytic activity in organic pollutant treatment. Some properties of Black-TiO2 were determined via common methods such as sensory analysis, X-Ray diffraction, and bandgap measurement obtained from UV-Vis spectroscopy. As a result, the material was successfully converted to more than 40% organic pollutant as Methyl Orange (C14H14N3NaO3S) for an hour, as two times higher than that of the amount converted by pristine TiO2. In addition, Black-TiO2 performed much better photocatalytic activity in an acidic medium in comparison with a neutral one, and the material also remained its activity as more than 90% after three time-continuous recycling operations.


2012 ◽  
Vol 455-456 ◽  
pp. 110-114 ◽  
Author(s):  
Xuan Dong Li ◽  
Xi Jiang Han ◽  
Wen Ying Wang ◽  
Xiao Hong Liu ◽  
Yan Wang ◽  
...  

Nb-doped TiO2 powders with different concentrations of Nb have been synthesized by a sol-gel method and characterized by a series of technologies including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. The photocatalytic activity of Nb-doped TiO2 is evaluated by degradation efficiency of methyl orange in aqueous solution. The results indicate that the photocatalytic activity of Nb-doped TiO2 synthesized with a Nb/Ti molar ratio of 5% is higher than that of TiO2 under the visible light.


2013 ◽  
Vol 860-863 ◽  
pp. 907-910
Author(s):  
Xiao Xia Lin ◽  
Jia Liu ◽  
De Gang Fu

B-doped TiO2nanotube arrays (B-TNTs) were synthesized by anodization method combined with dip-calcination technique. The physicochemical properties and surface morphology were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and UV-Vis diffuse reflectance spectrum (DRS). Methyl blue (MB) solution was utilized as the degradation model to evaluate the photocatalytic activity of B-TNTs under visible light irradiation. The results show B-TNTs shifts the absorption edge of TiO2nanotube arrays to the visible light region and B-TNTs displays higher photocatalytic activity compared with undoped TNTs.


2013 ◽  
Vol 864-867 ◽  
pp. 404-407
Author(s):  
Shi Zhao Kang ◽  
Tan Wu ◽  
Xiang Qing Li ◽  
Yi Lun Zhou ◽  
Jin Mu

Core-shell montmorillonite-TiO2 colloids were prepared in a hydrothermal process and characterized with transmission electron microscope, powder X-ray diffraction analysis, Brunauer-Emmett-Teller analysis and UV-vis spectra. Afterwards, their photocatalytic activity was investigated under UV irradiation using methyl orange as a model contaminant. In addition, the stability of the core-shell montmorillonite-TiO2 colloids was investigated by repeatedly performing methyl orange photocatalytic degradation experiments. The results indicate the as-prepared core-shell montmorillonite-TiO2 colloids are a highly efficient photocatalyst for the degradation of organic dyes in water. And this photocatalytic activity remains almost unchanged after eight successive cycles.


2012 ◽  
Vol 190-191 ◽  
pp. 534-538 ◽  
Author(s):  
Bin Xia Zhao ◽  
Li Ping Dang ◽  
Xiao Li Zhang ◽  
Na Yang ◽  
Yuan Yuan Sun

In order to obtain TiO2-pillared materials, montmorillonite (MMT) from Xinghe Co. of Neimeng as matrix, was used. The tetrabutyl titanate was used as precursor for the preparation of the TiO2-pillared montmorillonite, which was applied to introduce TiO2 into its interlayer space (15 mmol Ti/g clay). The as-prepared materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared spectroscopy (IR). The XRD patterns and the SEM photograph illustrated that the layers of MMT were delaminated and all samples were of the anatase phase. The TiO2-pillared montmorillonite was shown high photoactivity for the photodegradation of methyl orange dyestuff in aqueous solution under UV irradiation. The results showed that TiO2-pillared montmorillonite containing the anatase phase of TiO2 by calcination at 773 K and it was with the highest photocatalytic activity. Comparative photodegradation experiments were also conducted under different conditions. The experimental results demonstrated the feasibility of utilizing TiO2-pillared clays as a catalyst for removing methyl orange from water.


2019 ◽  
Vol 814 ◽  
pp. 487-492
Author(s):  
Xi Hao Lin ◽  
Pei Song Tang ◽  
Bei Bei Wang ◽  
Hai Qiang Tang

Using zinc acetate, glycerol alcohol and sodium hydroxide as principal raw materials, the ZnO microspheres were prepared by hydrothermal method at 200°C. The samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflectance spectroscopy (DRS). Using methyl orange as the degradation object, the photocatalytic activities and recycling stability of ZnO were characterized. The results show that ZnO samples are spherical and the average diameter is approximately 3-4μm. Moreover, the bandgap width is 3.1eV. Under ultraviolet light irradiation, it is testified that ZnO shows a excellent photocatalytic activity for the degradation of methyl orange. From experience, we can draw a conclusion that the ZnO samples were in line with first-order kinetics, with an apparent rate constant of 0.016min-1. At the same time, ZnO showed excellent recycling performance. Although the samples have been recycled three times, it still maintained high photocatalytic activity.


2012 ◽  
Vol 624 ◽  
pp. 88-93 ◽  
Author(s):  
En Lei Qi ◽  
Ben Niu ◽  
Shi Lei Zhang ◽  
Jie Qiang Wang

CeO2 nanobundles were obtained by the microwave homogeneous precipitation method using cerium nitrate and urea as raw materials. Ag nanoparticles were obtained by the microwave solvolthermal method using silver nitrate, PVP and ethanol as raw materials. Nanostructured Ag/CeO2 was prepared by the impregnation method. The products were characterized by X-ray diffraction, SEM, TEM, UV-vis spectrum, BET. The photocatalytic properties of CeO2 and Ag/CeO2 nanomaterials were evaluated by degradation of methyl orange. The results show that the photocatalytic degradation of modified cerium oxide modified by nano silver on methyl orange is significantly improved. For the Ag (0.1 wt%)/CeO2 material, the degradation rate on methyl orange is up to 83.2% under visible light irradiation for 1h. The catalytic activity of nanostructured Ag (0.1 wt%)/CeO2 in dye decolorization is substantially higher than the standard reference TiO2 P25.


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