Preparation and Characterization of H3PW12O40/TiO2-M (M=Fe, Co, Ni, Zn) and Photocatalytic Activity for Methyl Orange Decomposition

2014 ◽  
Vol 1073-1076 ◽  
pp. 202-209 ◽  
Author(s):  
Si Jing Chen ◽  
Qiang Gan ◽  
Hai Ru Shang ◽  
Xia Liu

Composites H3PW12O40/TiO2-M (M=Fe, Co, Ni, Zn) were synthesized by combining sol-gel technology with impregnation method. The structures and properties were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and UV-Vis diffuser reflectance spectrum (UV-Vis DRS). The XRD and FT-IR results showed that the TiO2 particles had the anatase phase, and the Keggin structure of H3PW12O40 remained intact. The UV-Vis DRS results indicated that compared with pure TiO2, an obvious red shift occurred after introducing H3PW12O40. The composites were used as heterogeneous photocatalyst to the degradation of methyl orange, and the influences of catalyst dosage, H3PW12O40 loading and metal ion species were studied. Results show that, under the optimum parameters pH value 2.00, 0.4 g·L-1 catalyst dosage and 30% H3PW12O40 loading, 96.6% methyl orange was degraded after 30 min irradiation (365 nm) using composite H3PW12O40/TiO2-Zn. The photodegradation process fitted Langmuir-Hinshelwood first order kinetics.

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.


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


2018 ◽  
Author(s):  
azadeh ebrahimian pirbazari ◽  
Pejman Monazzam ◽  
Behnam Fakhari Kisomi

In this work, TiO2 nanoparticles containing different amounts of cobalt were synthesized by sol-gel method using titanium (IV) isopropoxide and cobalt chloride as titanium and cobalt precursors, respectively. X-ray diffraction (XRD) results showed prepared samples include 100% anatase phase. The presence of cobalt in TiO2 nanoparticle network was established by XRD, scanning electron microscopy equipped with energy dispersive X-ray microanalysis (SEM-EDX), Fourier transform infrared (FT-IR) and N2 physisorption techniques. The increase of cobalt doping enhanced redshif in the diffuse reflectance spectra. The photocatalytic activity of the prepared samples was tested for degradation of methylene blue (MB) as a model of dye. Although the photocatalytic activity of pure TiO2 was found to be higher than that of Co/TiO2 samples under UV irradiation, the presence of 0.24% cobalt dopant in TiO2 nanoparticles resulted in a photocatalyst with the highest activity under visible light


2011 ◽  
Vol 183-185 ◽  
pp. 2028-2031
Author(s):  
Gui Rong Wang

TiO2 photocatalyst modified by N and Fe ions was loaded on self-made fly ash forming adsorbent (FFA) using the sol-gel dip-coating process. The crystal structure and photoadsorption ability was characterized by X-ray diffraction (XRD) and UV-Vis spectrophotometer, respectively. The photo catalytic degradation of Reactive Brilliant Blue KN-R using N, Fe-TiO2/FFA was examined. Effects of initial dye concentration, pH value and hydrogen peroxide dosage on degradation were studied. The degradation of the organic molecule followed a pseudo-first-order kinetics according to the Langmuir model. Under the optimum operation conditions, 30 mg/L KN-R could be decolorized over 97.47% within 75 min.


2017 ◽  
Vol 748 ◽  
pp. 413-417
Author(s):  
Chun Yu Long ◽  
Fang Fang Peng ◽  
Min Min Jin ◽  
Pei Song Tang ◽  
Hai Feng Chen

Using Pr (NO3)3, butyl titanate, ethylene glycol and citric acid as main raw materials, praseodymium titanate (Pr2Ti2O7) was prepared by the sol-gel process. The samples were characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), thermal gravity-differential thermal analysis (TG-DTA), diffuse-reflection spectra (DRS) and Fourier transform infrared (FT-IR). The effect of different calcination temperature and illumination time on the photocatalytic properties of Pr2Ti2O7 was investigated. It was found that the single phase Pr2Ti2O7 could be obtained through sol-gel process and calcination at 1000 °C. The Pr2Ti2O7 samples calcination at 1000 °C were uniform , and the resulting product had a particle size of 200 nm and an optical band gap of 3.26 eV. Under ultraviolet light, the degradation of methyl orange arrived to 80.11% after 180 min of photocatalytic reaction. The Pr2Ti2O7 samples showed good photocatalytic activity for decomposition of methyl orange.


2019 ◽  
Vol 56 ◽  
pp. 28-38 ◽  
Author(s):  
Uraiwan Werapun ◽  
Jaraslak Pechwang

TiO2 and iron-doped TiO2 were synthesized by sol-gel method. TiO2 and 0.5 %mol Fe:TiO2 were calcined at 500 and 800 °C for 3 h. The synthesized particles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-VIS diffuse reflectance spectrophotometry (UV/DRS), scanning electron microscopy (SEM) and scanning electron microscope-energy dispersive X-Ray analysis (SEM-EDX). The XRD patterns of all samples that were calcined at 500 °C showed only anatase phase. On increasing temperature from 500 to 800 °C, the anatase phase transformed to rutile phase. For 0.5 %mol Fe:TiO2, pseudobrookite (Fe2TiO5) phase was observed at 800 °C. The particles that contained rutile showed higher antibacterial activities against E.coli, B. subtilis, and S. aureus than anatase phase, under fluorescent irradiation.


2011 ◽  
Vol 233-235 ◽  
pp. 967-970 ◽  
Author(s):  
Wei Hong Huang ◽  
Rui Liu

The prepared composite photocatalyst H3PW12O40/TiO2 was synthesized by sol-gel impregnation method and characterized by scanning electron microscope(SEM), energy-dispersive X-ray spectroscopy(EDS), Fourier transform infrared(FT-IR), X-ray diffraction(XRD), UV-vis diffuse reflectance spectrum(DRS) to investigate its optical, physical and chemical properties. The results indicated that the modified catalyst was coated with P and W element, still have uniform anatase structure. Meanwhile, there is a chemical interaction exists between the Keggin unit and the surface of the titania matrix. Compared with original H4PW12O40 or TiO2 matrix, the adsorption threshold onset of the composite extended to the visible region. Effects of H3PW12O40/TiO2 dosage, pH value, initial p-NA concentration on the photocatalytic degradation of p-NA under 250W UV irradiation were investigated. The optimal H3PW12O40/TiO2 dosage and pH value for degradation of 10mg/L p-NA were o.6g/L and 3.0, respectively. The degradation rate of p-NA by H3PW12O40/TiO2 process could be fitted pseudo-first-order kinetics. Moreover, 66% degradation of p-NA was still observed in the 5th recycle experiment. Futhermore, 4-Aminophenol, Phenol, Hydroquinone, 4-Benzoquinone and other intermediate products were indentifieded by GC/MS and a possible reaction mechanism is proposed on the basis of all the information obtained from the analysis of FT-IR and the above intermediates.


2017 ◽  
Vol 5 (2) ◽  
pp. 90
Author(s):  
Yudha Ramanda ◽  
Kevin Thomas ◽  
Saifuddin Aziz ◽  
Kurniawan Mauludi ◽  
Eko Sri Kunarti

Synthesis of Fe3O4/SiO2/TiO2 nanocomposite and its application as photocatalyst in Carboxymethyl Cellulose (CMC) photocracking had been conducted. Magnetite preparation was carried out by sono-coprecipitation method. The deposition of SiO2 and TiO2 were performed by sol-gel method under ultrasonic irradiation. All material products were characterized by X-ray diffraction (XRD), Fourier transform infra-red spectrophotometry (FT-IR), and transmission electron microscopy (TEM). The final material product was also analysed by specular reflectance UV-Visible (SR-UV-Vis). The product of photocracking was analysed by gas chromatography – mass spectrometry (GC-MS).The XRD diffractogram and FT-IR spectra confirmed the presence of Fe3O4, SiO2, and anatase phase of TiO2. The TEM image revealed the presence of nanocomposite with core-shell structure. The SR-UV-Vis spectrum was used to determine band gap energy of the photocatalyst and it gave a result of 3.22 eV. The GC chromatogram of photocracking product indicated some major fractions. The MS spectra showed that some major fractions were smaller molecules including methanol, the component of biofuel.


2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
M. Rashidzadeh

Nanosized crystals of anatase phase with high-thermal stability was synthesized in the range of 15–17 nm via sol-gel method using titanium n-butoxide precursor. Synthesize was done at two different temperatures, that is, 200 and and the final products were calcined at . The final products were characterized by adsorption, X-ray diffraction, FT-IR, and TEM and tested in a photoreactor using fluorescien as model molecule. For thermal stability investigation, the sample prepared at was heated up to 800, 850, and , the XRD results showed that the synthesized anatase phase was stable up to . Photocatalytic activity of the prepared samples showed that the fluorescien degradation followed a pseudo-first-order kinetic.


2006 ◽  
Vol 11-12 ◽  
pp. 7-10
Author(s):  
T. Nishi ◽  
Sakae Tanemura ◽  
Lei Miao ◽  
Masaki Tanemura ◽  
K. Suzuki

We have prepared titania aerogel (=AG) embedded by NiB nano-clusters by sol-gel method, immersion of the prepared wet gel into the NiB dispersed solution, and the subsequent super critical drying (=SCD). The AG was characterized by X-ray diffraction (XRD), a transmission electron microscopy (TEM), and a fourier transform infrared spectrophotometer (FT-IR). XRD and selected area electron diffraction (SAED) patterns assured the formation of TiO2 anatase phase. TEM observation reveled the composition of TiO2 crystallites with about 4 nm in size. Catalyst performance for the ground sample was confirmed by chemical reaction of oxidation of benzene at low temperature, and the difference in catalyst performance between TiO2 AGs with and without the embedded NiB nano-clusters has been examined.


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