scholarly journals Mechanochemical Synthesis of Visible Light Sensitive Titanium Dioxide Photocatalyst

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Jan Šubrt ◽  
Jose M. Criado ◽  
Lórant Szatmáry ◽  
Maria J. Diánez-Millán ◽  
Nataliya Murafa ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Region ◽  
High Photocatalytic Activity ◽  
Photocatalytic Decomposition ◽  
Visible Absorption ◽  
Ground Sample ◽  
Ammonium Carbamate ◽  
Light Region ◽  
Anatase Nanoparticles ◽  
Kinetics Of

Phase transition of anatase nanoparticles into the phases TiO2-II and rutile under grinding was studied. The addition of ammonium carbamate to the reaction mixture inhibits the phase conversion and the cold welding of particles. The UV-visible absorption spectrum showed narrowing the band gap width after grinding with an ammonium carbamate additive resulting in shift of the light absorption of the ground sample towards the visible region. By EPR, intensive formation of OH•radical at irradiation of the sample with both UV (λ> 300 nm) and visible (λ> 435 nm) light was observed. High photocatalytic activity of the ground sample in visible light region was demonstrated also by measurement of kinetics of the photocatalytic decomposition of 4-chlorophenol.

Preparation of Visible-Light Responsive Photocatalyst SxTi1-XO2

2011 ◽  
Vol 694 ◽  
pp. 602-607
Author(s):  
Yong Qiang Wang ◽  
Fang Liu ◽  
Chao Cheng Zhao
Keyword(s):  
Visible Light ◽  
Visible Region ◽  
Pure Tio2 ◽  
Photocatalytic Decomposition ◽  
Surface Photovoltage ◽  
Acid Solutions ◽  
Surface Photovoltage Spectroscopy ◽  
Light Region ◽  
Hydrolysis Of ◽  
Sun Light

Sulfur-doped titanium dioxide powders (SxTi1-xO2) was prepared by calcinations, that is, the hydrolysis of acidic tetra-butyl tianate using thiourea in ethanol, followed by calcinations at temperatures about 500°C. Based on the characterizations of XRD, BET, surface photovoltage spectroscopy (SPS), electric-field-induced surface photovoltage spectroscopy (EFISPS) and XPS, it was found that the sulfur could restrain the crystallization transformation of TiO2 from anatase to rutile, although the calcinations temperature has attained 500°C, the crystallization still were anatase entirely. The catalysts exhibited photocatalytic activity in the visible light region owing to S-doping. The light absorption onset of SxTi1-xO2 was shifted to the visible region at 550nm compared to 329nm of pure TiO2. In the crystal, the S atoms occupied some of the lattice titanium atoms for form S-O bonds. Photocatalytic decomposition of benzoic acid solutions was carried out under simulated sun light, and the SxTi1-xO2 catalyst showed higher activity than pure TiO2.

scholarly journals SOLVOTHERMAL SYNTHESIS OF BI2WO6 AND ITS PHOTOCATALYTIC ACTIVITY UNDER VISIBLE LIGHT IRRADIATION

2018 ◽  
Vol 54 (4B) ◽  
pp. 42
Author(s):  
Trinh Duy Nguyen
Keyword(s):  
Absorption Spectrum ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Visible Region ◽  
High Photocatalytic Activity ◽  
Light Irradiation ◽  
Different Temperatures

Flower-like Bi2WO6 were successfully synthesized using the solvothermal method at different temperatures and characterized by XRD, FE-SEM, and DRS. We also investigated the photocatalytic activity of Bi2WO6 for the decomposition of rhodamine B under visible light irradiation. From XRD and SEM results, the reaction temperature has significant effects on the morphologies of the samples. From DRS results, Bi2WO6 samples displayed the absorption spectrum up to the visible region and then they showed the high photocatalytic activity under visible light irradiation, as a comparison with TiO2-P25.

scholarly journals Preparation of Fe-DopedTiO2Nanotubes and Their Photocatalytic Activities under Visible Light

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Honghui Teng ◽  
Shukun Xu ◽  
Dandan Sun ◽  
Ying Zhang
Keyword(s):  
Visible Light ◽  
Visible Region ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Ultrasonic Assisted ◽  
Uv Visible

Fe-doped TiO2nanotubes (Fe-TNTs) have been prepared by ultrasonic-assisted hydrothermal method. The structure and composition of the as-prepared TiO2nanotubes were characterized by transmission electron microscopy, X-ray diffraction, and UV-Visible absorption spectroscopy. Their photocatalytic activities were evaluated by the degradation of MO under visible light. The UV-visible absorption spectra of the Fe-TNT showed a red shift and an enhancement of the absorption in the visible region compared to the pure TNT. The Fe-TNTs were provided with good photocatalytic activities and photostability and under visible light irradiation, and the optimum molar ratio of Ti : Fe was found to be 100 : 1 in our experiments.

Extension of the Optical Absorption of TiO2 Nanopaticles to Visible Light Region by Doping with Cobalt

2011 ◽  
Vol 181-182 ◽  
pp. 348-351
Author(s):  
Yi Ding ◽  
Xiao Jun Xu ◽  
Zhang Hua Gan ◽  
Rui Xiong ◽  
Hai Lin Liu
Keyword(s):  
Optical Absorption ◽  
Visible Light ◽  
Light Absorption ◽  
Anatase Phase ◽  
Electron Transition ◽  
Binding Energies ◽  
Visible Absorption ◽  
Visible Light Absorption ◽  
X Ray ◽  
Light Region

TiO2 nanoparticles doped with different cobalt concentrations were fabricated by using so-gel method. The crystal structures and the morphology of the samples were characterized by using x-ray diffractmetry (XRD) and transmission electron microscopy (TEM), respectively. It was found that all the samples are anatase phase and the nanoparticles are of the size around 10 nm. Investigations of the binding energies of different element with X-ray photoelectron spectrometry (XPS) revealed that Co ions are in Co2+ state and take the substitutional sites. No Co clusters were detected in the samples. The optical absorption properties of the samples were studied by using UV-vis absorption spectroscopy. It was noticed that cobalt doped TiO2 has a significant visible light absorption in contrast to pure TiO2: besides a noticeable red shift in absorption edge, an extra visible light absorption peak appears at a wavelength around 600 nm. The visible absorption in cobalt doped TiO2 may attribute to the electron transition from impurity levels induced by the substitutional Co ions and the oxygen vacancies to the conduct band.

scholarly journals Nanocrystalline N-DopedTiO2Powders: Mild Hydrothermal Synthesis and Photocatalytic Degradation of Phenol under Visible Light Irradiation

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Junna Xu ◽  
Feng Wang ◽  
Wenxiu Liu ◽  
Wenbin Cao
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Ph Value ◽  
Guanidine Hydrochloride ◽  
Initial Pressure ◽  
Light Irradiation ◽  
Titanyl Sulfate ◽  
Visible Absorption ◽  
Light Region ◽  
Initial Ph

Nitrogen-doped TiO2powders have been prepared using technical guanidine hydrochloride, titanyl sulfate, and urea as precursors via a mild hydrothermal method under initial pressure of 3MPa,150∘Cholding for 2h without any postheat treatment for crystallization. The nanocrystalline N-doped TiO2powders were composed of anatase TiO2by XRD. The grain size was estimated as about 10 nm, and the BET specific surface area of the powder was measured as 154.7 m2/g. The UV-visible absorption spectra indicated that the absorption edge of the N-doped TiO2powders had been red shifted into the visible light region. The photocatalytic performance of the synthesized powders was evaluated by degradation of phenol under visible light irradiation. And the effects of the catalyst load and the initial pH value on the photodegradation were also investigated.

scholarly journals Visible Light-Driven high Photocatalytic Activity of Cu-Doped TiO2 Nanoparticles Synthesized by Hydrothermal Method

2018 ◽  
Vol 15 (3) ◽  
pp. 197-208 ◽  
Author(s):  
Ravi Kamble ◽  
Smita Mahajan ◽  
Vijaya Puri ◽  
Harish Shinde ◽  
Kalayanrao Garadkar
Keyword(s):  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Hydrothermal Method ◽  
Anatase Phase ◽  
Visible Region ◽  
Oxygen Demand ◽  
High Photocatalytic Activity ◽  
Tio2 Nps ◽  
Doped Tio2 ◽  
Tio2 Lattice

TiO2 and Cu-doped TiO2 nanoparticles (NPs) with totally extraordinary substance of Cu by exploitation hydrothermal method. The part immaculateness, morphology, molecule estimate, optical properties, and elemental composition of as-incorporated Cu-doped TiO2 NPs were investigated by numerous systematic methods. The XRD designs unveiled Cu-doped TiO2 NPs inside the part unadulterated anatase phase. The plane of (101) XRD and XPS results show the lucky doping of Cu2+ inside the TiO2 lattice. The optical edges of Cu-doped TiO2 demonstrated a transparent light absorption in visible region that assumes an essential part inside the photocatalytic action underneath characteristic daylight. Certain Cu2+ content shows least PL intensity that backings the decrease in recombination rate of charge species. In addition, to get a handle on photocatalytic action, we have tried Cu-doped TiO2 for the degradation of Malachite Green (MG) under visible light. A large portion of 85% degradation was found for Cu-doped TiO2 (1.71 wt.%) underneath daylight minimum of 180 min, severally, that is past that of TiO2 (53%). Also, the degradation of the MG was affirmed by measurement of the chemical oxygen demand of the photodegraded solution. These outcomes demonstrates that the Cu-doped TiO2 NPs are extremely productive for the photodegration of the MG.

Photocatalytic Degradation of Methylene Blue Aqueous Solution under Visible Light Irradiation by Using N-Doped Titanium Dioxide

2007 ◽  
Vol 336-338 ◽  
pp. 1972-1975 ◽  
Author(s):  
Yan Hong Li ◽  
Wen Bin Cao ◽  
Fan Yong Ran ◽  
Xiao Ning Zhang
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Guanidine Hydrochloride ◽  
Visible Region ◽  
High Photocatalytic Activity ◽  
Light Irradiation ◽  
Nanocrystalline Tio2 ◽  
Doped Tio2

N-doped TiO2 powders with high photocatalytic activity under visible-light irradiation have been prepared by calcining anatase nanocrystalline TiO2 powders and guanidine hydrochloride at 350 °C, 450 °C, 550 °C and 650 °C with the holding time ranged from 1.5 h to 3 h, respectively. The guanidine hydrochloride content was varied from 1 to 6 M for the experiments. XRD patterns indicate that all the powders are anatase crystalline phase. The specific surface area is 25~45 m2/g measured by BET method. XPS results show that N atoms were incorporated into the lattice of TiO2 and the amount of N doped in TiO2 is reached up to 8.26 at%. UV-Vis absorption spectra show that the absorption edge of the synthesized N-doped TiO2 powders, calcined at 350 °C for 2.5 h, has red-shifted well into visible region up to 700 nm. Degradation of methylene blue (MB) aqueous solution has been investigated by UV-Vis light spectrophotometer. The 400-mL 10 mg/L aqueous solution of methylene blue could be degraded completely with 4 g N-doped TiO2 within 4.5 h of visible light irradiation.

scholarly journals MoS2/Cu/TiO2 nanoparticles: synthesis, characterization and effect on photocatalytic decomposition of methylene blue in water under visible light

2018 ◽  
Vol 2017 (1) ◽  
pp. 184-193 ◽  
Author(s):  
Desireé M. de los Santos ◽  
Sara Chahid ◽  
Rodrigo Alcántara ◽  
Javier Navas ◽  
Teresa Aguilar ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Visible Region ◽  
Pure Tio2 ◽  
Photocatalytic Decomposition ◽  
Tio2 Sample ◽  
X Ray ◽  
Vis Spectroscopy

Abstract Photodegradation processes are of great interest in a range of applications, one of which is the photodecomposition of pollutants. For this reason, analysing nanoparticles that improve the efficiency of these processes under solar radiation are very necessary. Thus, in this study, TiO2 was doped with Mo and Cu using low-temperature hydrolysis as the method of synthesis. Pure TiO2 and x%MoS2/Cu/TiO2 nanoparticles were prepared, where x is the theoretical quantity of MoS2 added (0.0%, 1.0%, 5.5%, 10.0%), setting the nominal quantity of Cu at 0.5 wt.%. The samples obtained were characterized by X-ray diffraction, Raman spectroscopy, X-ray electron spectroscopy and UV-Vis spectroscopy in diffuse reflectance mode. The results suggest that the TiO2 structure was doped with the Mo6+ and Cu2+ ions in the position of the Ti4+. The x%MoS2/Cu/TiO2 samples presented lower band gap energy values and greater optical absorption in the visible region than the pure TiO2 sample. Lastly, the photocatalytic activity of the samples was assessed by means of the photodegradation of methylene blue under visible light. The results show that when the quantity of Mo in the co-doped samples increased (x%MoS2/Cu/TiO2) there were significant increases of up to 93% in the photocatalytic activity.

Photocatalytic Activity of TiO2-C Composites under the Visible Light

2009 ◽  
Vol 610-613 ◽  
pp. 310-315
Author(s):  
Jin Huo Li ◽  
De Gui Zhu ◽  
Zong Yue Xue ◽  
Shuang Quan Guo
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
High Photocatalytic Activity ◽  
Ultraviolet Region ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Nano Tio2 ◽  
Light Region

TiO2-C composites of high photocatalytic activity were in-situ fabricated with nano-TiO2 powders and resins. The composites were characterized by differential scanning calorimetry and thermal gravimetric analysis (DSC-TG), X-ray diffraction (XRD), UV-Vis diffuse reflection spectrum (DRS), transmission electron microscope (TEM) and scan electronic microscopy (SEM). XRD results indicated that the composites consist of carbon and anatase phases. UV-Vis DRS showed that composites not only have a good performance in the ultraviolet region, but also have a very good performance in the visible light region. Photocatalysis degradations of methyl orange with purity nano-TiO2 and TiO2-C composite were tested by lighting of visible light. After methyl orange liquid was lighted by visible light for 1 hour, the decolorization ratio of methyl orange can be up to 96.3%( reactive brilliant red X-3B:98.7%) with TiO2-C powders, while it was only 34.7% (reactive brilliant red X-3B:66.9%) with purity nano-TiO2 powders. In-situ fabricated carbon can change the width of energy band of TiO2 and adsorb methyl orange and reactive brilliant red X-3B molecules. The former accelerate the absorption of visible light, and the later raise the decomposition rate of methyl orange and reactive brilliant red X-3B. All of these can improve photocatalytic activity of TiO2-C composites under the visible light.

scholarly journals Synthesis, Characterization, and Investigation of Visible Light Photocatalytic Activity of C Doped TiO2/CdS Core-Shell Nanocomposite

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Atul B. Lavand ◽  
Yuvraj S. Malghe ◽  
Suraj H. Singh
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Region ◽  
Cds Nanoparticles ◽  
Core Shell ◽  
Visible Absorption ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Uv Visible ◽  
Visible Light Photocatalytic

Carbon (C) doped TiO2/CdS core-shell nanocomposite (C/TiO2/CdS) was synthesized using microemulsion method. Synthesized powder was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and UV-visible spectrophotometery. TEM images reveal that C/TiO2/CdS core-shell heterostructure is successfully prepared with CdS as a core and C doped TiO2 as a shell. UV-visible absorption spectra show that CdS nanoparticles act as a sensitizer and effectively enhance the photoabsorption capacity of C/TiO2/CdS nanocomposite in visible region. Visible light photocatalytic activity of synthesized nanocomposite was evaluated for the degradation of methylene blue. C/TiO2/CdS core-shell nanocomposite exhibits better photocatalytic activity as compared to bare TiO2, CdS, CdS/TiO2, and C doped TiO2.

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