Co-reporter:Zuyun Zhang, Caiyun Jiang, Ping Du, Yuping Wang
Ceramics International 2015 Volume 41(Issue 3) pp:3932-3939
Publication Date(Web):April 2015
DOI:10.1016/j.ceramint.2014.11.076
The heterostructured Bi2Ti2O7/ TiO2 composites with different shapes were synthesized by a simple glycerol-assisted alcoholthermal method. The as-prepared Bi2Ti2O7/ TiO2 composites were characterized by UV–vis, XRD, FESEM, TEM, BET, TG/DTA, EDS and photoluminescence (PL) spectroscopy. The effects of addition amount of glycerol on the structure and properties of products were investigated. The photocatalytic activities of the as-prepared samples were evaluated through photocatalytic decolorization of methylene blue aqueous solution. The results showed that structure and morphology of Bi2Ti2O7/TiO2 heterojunction can be readily controlled by adjusting the volume ratio of glycerol and ethanol. When volume ratio of glycerol and ethanol was 0, 0.05 and 0.10, the morphology of Bi2Ti2O7/ TiO2 heterojunction was granular, rugby and petal shaped, respectively. In comparison with that of commercial grade nano-titanium oxide (referred to as P25), the Bi2Ti2O7/ TiO2 heterojunction had enhanced photocatalytic efficiency irradiated under simulated sunlight. Petals shaped Bi2Ti2O7/TiO2 heterojunction had higher photocatalytic activities because it possessed higher specific surface areas and larger pore volume.
The growth and assembly of GNPs are carried out in a one-step procedure using gallic acid (GA) as reducer and stabilizer. Due to the coordination behavior of Pb2+ with the GA molecularly bonded onto the surface of GNPs, the nanoassemblies can be used to quantitatively detect Pb2+ in aqueous media with high sensitivity when the pH of the solution is above 4.2. The spectra were monitored by a UV-vis-near-infrared (NIR) spectrophotometer, and the wavelength changes were adopted as detection signals. The detection limit of this sensor to Pb2+ concentration is 10−9 M, and the linear response range of Pb2+ concentration is from 2.68 × 10−8 M to 4.95 × 10−6 M. The method was used to detect the lead content of tea, and a good result was obtained which was consistent with that from ICP-MS.
Co-reporter:Jiankun Ren, Guoqing Liu, Yuping Wang, Qian Shi
Materials Letters 2012 Volume 76() pp:184-186
Publication Date(Web):1 June 2012
DOI:10.1016/j.matlet.2012.02.073
In this study, we report a novel synthesis procedure of Bi2Ti2O7 pyrochlore crystals with deviation from stoichiometry through a very convenient solvothermal method. The bismuth nitrate and tetrabutyl titanate are used as reactant, and ethanol and glycerin are used as solvent. As alcohol promotes the formation of bismuth oxide sol but inhibits the development and growth of nanometer TiO2 crystal, the phase pure Bi2Ti2O7 is formed when the molar ratio of bismuth nitrate and tetrabutyl titanate is 0.4:1. The sample was characterized by XRD, FT-IR, FE-SEM, TEM, BET and UV–vis method. The as-prepared Bi2Ti2O7 with a good sunlight activity is spherical and average particle size is about 3 nm.Highlights► Nanosized Bi2Ti2O7 was first prepared by ethanol solvothermal method. ► The phase pure Bi2Ti2O7 is formed with deviation from stoichiometry. ► The well crystalline Bi2Ti2O7 has formed at lower temperature.
Iodine-doped mesoporous TiO2 (I/TiO2) was prepared by hydrothermal method, using tetrabutyl titanate as precursor, potassium iodate as iodine sources. The as-prepared I/TiO2 catalysts were characterized by UV–vis, XRD, TEM, BET, TG/DTA, XPS and photoluminescence (PL) spectroscopy. Production of OH radicals on the I/TiO2 surface was detected by the PL technique using terephthalic acid as a probe molecule. The effects of hydrothermal reaction temperature, calcination temperature and iodine doping content on the structure and properties of the catalysts were investigated. The results showed that iodine-doped TiO2 calcinated at 300 °C have good anatase crystal. The optimal hydrothermal conditions have been determined to be that reaction temperature 120 °C, calcinated temperature 300 °C and added 1.16 mmol iodine dopants. The average particle size of I/TiO2 synthesized under optimal condition (I-3 sample) is about 3.9 nm. The I-3 photocatalyst contains 100% anatase crystalline phase of TiO2. BET specific surface area of I-3 sample is184.8 m2 g−1 and is 3.67 times that of pure TiO2 (50.37 m2 g−1). Iodine in I/TiO2 catalyst mainly exists in the form of I2, and photoactivity of I/TiO2 catalyst in visible light comes from photosensitize of I2. I/TiO2 catalysis shows very high efficiency for the degradation of phenol under visible light.
Materials Chemistry and Physics 2011 Volume 130(1–2) pp:493-499
Publication Date(Web):17 October 2011
DOI:10.1016/j.matchemphys.2011.07.020
The mesoporous anatase TiO2 nanoparticles with great surface areas were prepared using iodine ion as dopant by sol–gel method. The as-prepared samples were characterized by differential thermal analysis, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, and UV–visible diffuse reflectance spectroscopy. The photocatalytic activity of the as-prepared samples was evaluated through photocatalytic decolorization of methylene blue aqueous solution. The above results of the characterization test not only indicate that iodine ion can inhibit the collapse of mesoporous channels resulting from the overquick dehydration among the free hydroxyl groups and plays a part in structure-directing, but also the calcination temperature has a crucial effect on the mesoporous structure and the amount of iodine doped in TiO2. The BET surface area of the as-prepared mesoporous TiO2 (208.98 m2 g−1) calcinated at 300 °C is 4 times larger than that of the pure TiO2 (50.37 m2 g−1). The catalyst doped with 13.2%(mole ratio) I and calcinated at 300 °C has the best performance. The efficiency of photocatalysis for MB is greatly improved with TiO2 doped by iodine ion under UV and visible light irradiation.Highlights► Anatase and mesoporous TiO2 doped with iodine ion is prepared by improved gel–sol method. ► Iodine ion may combine with hydroxyl to form macromolecular complex. ► Iodine ion plays a part in structure-directing and structure-supporting to some extent. ► The calcination temperature affects the morphology of iodine ion doped TiO2 nanoparticles.
S-doped TiO2 (S-TiO2) photocatalyst was synthesized by sol–gel method with tetrabutyl titanate and thiourea as precursor. S-TiO2 was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis absorption spectroscopy, transmission electron microscopy (TEM) and the photocatalytic activity was evaluated by 1-naphthol-5-sulfonic acid (L-acid) under UV, visible light and solar light radiation. The results showed that doped S could improve photoabsorption property of TiO2 in the visible region, leading the increase in the photocatalytical activity of TiO2.
The average particle size of the S-TiO2 photocatalyst is about 10 nm. The S-TiO2-4 photocatalyst contains 100% anatase crystalline phase of TiO2. In the S-TiO2-4 photocatalyst, S does not exist independently, but is incorporated into the crystal lattice of TiO2. In the inner crystal lattice of the S-TiO2-4 photocatalyst, S as S2− replaces O in TiO2, while on the surface of crystal lattice, S exists as S4+ and S6+.
The photocatalytical activity of S-TiO2-4 photocatalyst for the photodegradation of L-acid is better than that of pure TiO2. Under the same conditions, the photodegradation efficiency of L-acid for the S-TiO2-4 photocatalyst and the solar light irradiation is 85.1%, while it is only 26.4% for pure TiO2. In addition, the final products of the photocatalysis of L-acid using the S-TiO2-4 photocatalyst are not organic compounds with low molecular weight, but the inorganic compounds.
The growth and assembly of GNPs are carried out in a one-step procedure using gallic acid (GA) as reducer and stabilizer. Due to the coordination behavior of Pb2+ with the GA molecularly bonded onto the surface of GNPs, the nanoassemblies can be used to quantitatively detect Pb2+ in aqueous media with high sensitivity when the pH of the solution is above 4.2. The spectra were monitored by a UV-vis-near-infrared (NIR) spectrophotometer, and the wavelength changes were adopted as detection signals. The detection limit of this sensor to Pb2+ concentration is 10−9 M, and the linear response range of Pb2+ concentration is from 2.68 × 10−8 M to 4.95 × 10−6 M. The method was used to detect the lead content of tea, and a good result was obtained which was consistent with that from ICP-MS.
![1-(4'-Methoxy-[1,1'-biphenyl]-4-yl)ethanone](http://img.cochemist.com/ccimg/13100/13021-18-6.png)
![1-(4'-Methoxy-[1,1'-biphenyl]-4-yl)ethanone](http://img.cochemist.com/ccimg/13100/13021-18-6_b.png)
