scholarly journals Increase of the Photocatalytic Activity of by Carbon and Iron Modifications

2008 ◽  
Vol 2008 ◽  
pp. 1-15 ◽  
Author(s):  
Beata Tryba
Keyword(s):  
Photocatalytic Activity ◽  
Organic Compounds ◽  
Visible Light Irradiation ◽  
Organic Molecules ◽  
Visible Region ◽  
Photocatalytic Decomposition ◽  
Oh Radicals ◽  
Carbon Doped ◽  
Free Carriers ◽  
Hole Scavenger

Modification of by doping of a residue carbon and iron can give enhanced photoactivity of . Iron adsorbed on the surface of can be an electron or hole scavenger and results in the improvement of the separation of free carriers. The presence of carbon can increase the concentration of organic pollutants on the surface of facilitating the contact of the reactive species with the organic molecules. Carbon-doped can extend the absorption of the light to the visible region and makes the photocatalysts active under visible-light irradiation. It was proved that modified by carbon and iron can work in both photocatalysis and photo-Fenton processes, when is used, enhancing markedly the rate of the organic compounds decomposition such as phenol, humic acids and dyes. The photocatalytic decomposition of organic compounds on modified by iron and carbon is going by the complex reactions of iron with the intermediates, what significantly accelerate the process of their decomposition. The presence of carbon in such photocatalyst retards the inconvenient reaction of OH radicals scavenging by , which occurs when Fe- photocatalyst is used.

scholarly journals Carbon modified TiO2 photocatalysts for water purification

2009 ◽  
Vol 11 (2) ◽  
pp. 46-50 ◽  
Author(s):  
Antoni Morawski ◽  
Magdalena Janus ◽  
Beata Tryba ◽  
Masahiro Toyoda ◽  
Tomoki Tsumura ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Water Purification ◽  
Visible Region ◽  
Carbon Layer ◽  
Photocatalytic Decomposition ◽  
Visible Range ◽  
Tio2 Photocatalysts ◽  
Carbon Doped ◽  
Carbon Coated

Carbon modified TiO2 photocatalysts for water purification Carbon can form different structures with TiO2: carbon-doped TiO2, carbon coated TiO2 and composites of TiO2 and carbon. The presence of carbon layer on the surface of TiO2 as well as the presence of porous carbon in the composites with TiO2 can increase the concentration of organic pollutants on the surface of TiO2, facilitating the contact of the reactive species with the organic molecules. Carbon-doped TiO2 can extend the absorption of the light to the visible region by the narrowing of the band gap and makes the photocatalysts active under visible light irradiation. TiO2 loaded carbon can also work as a photocatalyst, on which the molecules are adsorbed in the pores of carbon and then they undergo the photocatalytic decomposition with UV irradiation. Enhanced photocatalytic activity for the destruction of some organic compounds in water was noticed on the carbon coated TiO2 and TiO2 loaded activated carbon, mostly because of the adsorptive role of carbon. However, in carbon-doped TiO2, the role of carbon is somewhat different, the replacement of carbon atom with Ti or oxygen and formation of oxygen vacancies are responsible for extending its photocatalytic activity towards the visible range.

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.

Comparison of photocatalytic activities of two kinds of lead magnesium niobate for decomposition of organic compounds under visible-light irradiation

2007 ◽  
Vol 22 (9) ◽  
pp. 2590-2597 ◽  
Author(s):  
Tetsuya Kako ◽  
Jinhua Ye
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Organic Compounds ◽  
Visible Light Irradiation ◽  
Band Gaps ◽  
Lead Magnesium Niobate ◽  
Light Irradiation ◽  
Photocatalytic Activities ◽  
Lead Magnesium ◽  
First Time

Two new oxide photocatalysts in the Pb–Mg–Nb ternary system, Pb3MgNb2O9 (PMN) and Pb1.83Mg0.29Nb1.71O6.39, have been synthesized, and their photophysical and photocatalytic properties were investigated for the first time. The band gaps of PMN and Pb1.83Mg0.29Nb1.71O6.39 were estimated to be 3.2 and 2.8 eV, respectively, from their absorption spectra. The photocatalytic activity evaluated from the decomposition of 2-propanol into acetone under visible-light irradiation indicated that Pb1.83Mg0.29Nb1.71O6.39 exhibited at least 20 times higher activity than PMN and has a strong oxidizing potential to mineralize organic compounds.

Enhanced hydrogen production by carbon-doped TiO2 decorated with reduced graphene oxide (rGO) under visible light irradiation

RSC Advances ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 2479-2488 ◽  
Author(s):  
Liyuan Kuang ◽  
Wen Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Hydrogen Production ◽  
Visible Light ◽  
Reduced Graphene Oxide ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Hybrid Nanocomposite ◽  
Carbon Doped ◽  
Reduced Graphene

Carbon doped TiO2 anchored to reduced graphene oxide formed a hybrid nanocomposite (C-TiO2/rGO) that exhibited greater photocatalytic activity and stability.

Novel one-dimensional Bi2O3–Bi2WO6 p–n hierarchical heterojunction with enhanced photocatalytic activity

2014 ◽  
Vol 2 (22) ◽  
pp. 8517-8524 ◽  
Author(s):  
Yin Peng ◽  
Mei Yan ◽  
Qing-Guo Chen ◽  
Cong-Min Fan ◽  
Hai-Yan Zhou ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Organic Compounds ◽  
Visible Light Irradiation ◽  
Electrostatic Field ◽  
High Photocatalytic Activity ◽  
Light Irradiation ◽  
Junction Region ◽  
One Dimensional ◽  
Photogenerated Electrons

A novel Bi2O3–Bi2WO6 p–n junction photocatalyst exhibits high photocatalytic activity for the degradation of organic compounds under solar/visible light irradiation, which is ascribed to the effective separation of photogenerated electrons and holes by the internal electrostatic field in the junction region.

ELECTRONIC STRUCTURES OF S-DOPED ANATASE AND RUTILE TiO2

2007 ◽  
Vol 06 (01) ◽  
pp. 23-32 ◽  
Author(s):  
XIN-GUO MA ◽  
CHAO-QUN TANG ◽  
XIAO-HUA YANG
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Valence Band ◽  
Visible Light Irradiation ◽  
Electronic Structures ◽  
Density Functional ◽  
Visible Region ◽  
Light Irradiation ◽  
Band Shift ◽  
Deep Impurity

The electronic structures of S -doped TiO 2 have been carried out by first-principles calculations based on density functional theory with plane-wave ultrasoft pseudopotential method. Comparing anion doping with cation doping in anatase and rutile, we found different energy band structures and origins of photoactivity of S -doped TiO 2. For anion-doped TiO 2, new S –3p bands appear and which lie slightly above the top of the O –2p valence band. It plays a significant role in increasing absorbance in the visible region, resulting in improvement in photocatalytic activity under visible-light irradiation. For cation-doped TiO 2, the potential of the O –2p valence band shift much downwards, yielding the stronger oxidative power than that of undoped and S anion-doped TiO 2. Nevertheless, the deep impurity states in BG (bond gap) that originate from the S -dopant have negative effects on the recombination of the photoexcited electrons and holes. From our calculated results, we can explain their differences in photocatalytic activity under visible-light irradiation.

A simple method to synthesise Ag-doped TiO2 photocatalysts with different Ag0:Ag2O atomic ratios for enhancing visible-light photocatalytic activity

2017 ◽  
Vol 41 (8) ◽  
pp. 475-483 ◽  
Author(s):  
C. Chen ◽  
X. F. Lei ◽  
M. Z. Xue
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Absorption ◽  
Separation Efficiency ◽  
Visible Region ◽  
Light Irradiation ◽  
Electron Hole ◽  
X Ray

Pure anatase TiO2 photocatalysts with different Ag contents were prepared via a simple sol-gel method. The as-prepared anatase Ag-doped TiO2 photocatalysts were characterised by X-ray diffraction, transmission electron microscopy, UV-Vis diffuse reflectance spectra, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, thermal gravity and differential thermal analysis, scanning electron microscopy and N2 adsorption–desorption measurements (BET). Compared with pure TiO2, Ag-doped anatase TiO2 photocatalysts exhibited not only increases in light absorption in the visible region, the separation efficiency of electron–hole pairs and surface area, but also inhibition of the titania phase transition from anatase to rutile. Photoreduction results showed that Ag-doped anatase TiO2 photocatalysts have greatly improved photocatalytic activity, compared with pure TiO2, and the reduction of Cr(VI) under visible light irradiation was much higher than that of pure TiO2. The optimum Ag content was 1.0 mol%, which led to the complete reduction of Cr(VI) under visible light irradiation (λ > 420 nm) for 4 h. The enhanced photocatalytic activity was attributed to the synergic effect of the pure anatase structure, and the increased light absorption in the visible region, separation efficiency of electron–hole pairs and atomic ratio of Ag0:Ag2O.

N,Fe Nano-TiO2 Doped on the Fly Ash Forming Absorbent and the Photocatalytic Activity Study

2013 ◽  
Vol 773 ◽  
pp. 912-916
Author(s):  
Yong Mei Liu ◽  
Zhuan Nian Liu ◽  
Xiao Gang Han
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Fly Ash ◽  
Visible Light Irradiation ◽  
Degradation Rate ◽  
Sol Gel ◽  
Visible Region ◽  
Dip Coating ◽  
Structure And Properties ◽  
Dip Coating Technique

nanoTiO2photocatalyst modified by N and Fe3+ion were loaded on fly ash forming adsorbent (FFA) using the sol-gel dip-coating technique. The structure and properties of the samples were characterized by UV-Vis spectrum, SEM and XRD. The related influencing factors were also discussed. The results showed that modified TiO2was immobilized on the surface of FFA in the form of nanocrystalline and an apparent absorption peak appears in the visible region of photocatalyst doped with N,Fe ion. Moreover, under visible light irradiation for 6h, the degradation rate of 50mg/L of methylene blue by loaded catalyst reached 92.6 %.

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