scholarly journals Improvement of Orange II Photobleaching by Moderate Ga3+Doping of Titania and Detrimental Effect of Structural Disorder on Ga Overloading

2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
Václav Štengl ◽  
Jiří Henych ◽  
Michaela Slušná ◽  
Tomáš Matys Grygar ◽  
Jana Velická ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Detrimental Effect ◽  
Structural Disorder ◽  
Orange Ii ◽  
Phase Content ◽  
Titania Sample ◽  
Hydrolysis Of ◽  
Positive Effect ◽  
Homogeneous Hydrolysis

Highly photoactive Ga3+-doped anatase modification of titania was prepared by homogeneous hydrolysis of aqueous solutions mixture of titanium oxo-sulphate TiOSO4and gallium(III) nitrate with urea. Incorporation of Ga3+into the anatase lattice has a clear positive effect on the photocatalytic activity under UV and Vis light irradiation up to a certain extent of Ga. Ga3+doping decreased the size of the crystallites, increased surface area, and affected texture of the samples. Higher amount of gallium leads to the formation of a nondiffractive phase, probably photocatalytically inactive. The titania sample with 2.18 wt.% Ge3+had the highest activity during the photocatalysed degradation in the UV and visible light regions; the total bleaching of dye Orange II was achieved within 29 minutes. Ga concentration larger than 5% (up to 15%) significantly inhibited the growth of the anatase crystal domains which formed the nondiffractive phase content and led to remarkable worsening of the photobleaching efficiency.

Hydrothermal Synthesis of Nanosized TiO2 Using Basic Peptizing Agents and their Photocatalytic Activity on the Decomposition of Orange II

2007 ◽  
Vol 544-545 ◽  
pp. 71-74
Author(s):  
Jun Ho Kim ◽  
Kwon Taek Lim ◽  
Gun Dae Lee ◽  
Seong Soo Park ◽  
Seong Soo Hong
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Batch Reactor ◽  
Anatase Phase ◽  
Photocatalytic Decomposition ◽  
Molar Ratio ◽  
Orange Ii ◽  
Titanium Tetraisopropoxide ◽  
Peptizing Agent ◽  
Hydrolysis Of

TiO2 nanoparticles were prepared using the hydrolysis of titanium tetraisopropoxide (TTIP) using TENOH as a peptizing agent in the hydrothermal method. The physical properties of prepared nanosized TiO2 particles were investigated. The photocatalytic degradation of orange II has been studied using a batch reactor in the presence of UV light. The crystallite size of the anatase phase is increased from 15 to 30 nm as the molar ratio of TENOH/TTIP increases from 0.1 to 1.0. The titania particle prepared at TENOH/TTIP molar ratio=0.1 shows the highest activity on the photocatalytic decomposition of orange II and the photocatalytic activity decreases according to an increase in TENOH/TTIP molar ratio. In addition, the titania particles prepared at 160oC shows the highest activity on the photocatalytic decomposition of orange II

scholarly journals The Simplest Way to Iodine-Doped Anatase for Photocatalysts Activated by Visible Light

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Václav Štengl ◽  
Tomáš Matys Grygar
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Aqueous Suspension ◽  
Organometallic Compounds ◽  
Orange Ii ◽  
Iodine Doping ◽  
Doped Titania

Iodine-doped TiO2was prepared by thermal hydrolysis of aqueous solutions of the titanium peroxo-complex, which includes no organic solvents or organometallic compounds. The synthesized samples were characterized by X-ray diffraction (XRD), Raman spectroscopy (RS), infrared spectroscopy (IR), specific surface area (BET), and porosity determination (BJH). The morphology and particle size was determined by high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). All prepared samples have a red-shifted band-gap transition, well crystalline anatase structure, and porous particles with a 100–200 m2 g−1specific surface area. The photocatalytic activity of iodine-doped titania samples was determined by decomposition of Orange II dye during irradiation at 365 nm and 400 nm. Iodine doping promotes the titania photocatalytic activity very efficiently under visible light irradiation. The titania sample with 0.32 wt.% I has the highest catalytic activity during the photocatalyzed degradation of Orange II dye in an aqueous suspension in the UV and visible regions.

Synthesis, Characterizations and Photocatalytic Activity of Mesoporous TiO2 Using Typha Latifolia as Template

2014 ◽  
Vol 1053 ◽  
pp. 495-502
Author(s):  
Ying Chun Miao ◽  
Guang Chen ◽  
Xiao Ling Xu
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Typha Latifolia ◽  
Mesoporous Titania ◽  
Residual Carbon ◽  
X Ray Diffraction ◽  
Silica Sample ◽  
Carbon Species ◽  
Titania Sample ◽  
Adsorption Desorption

Typha latifolia were successfully used as template to synthesize mesoporous titania and silica with efficient photocatalytic activity under solar and visible light. Both two titania and silica samples were characterized by a combination of various physicochemical techniques, such as, N2 adsorption/ desorption isotherm, diffuse reflectance UV-vis, and X-ray diffraction. It was found that both two synthesized samples exhibited similar morphologies to the original templates. The presence of the residual carbon species of mesoporous titania and silica strongly affects their photocatalytic activity. The photoactivity of P25 TiO2 could not almost exhibit while both mesoporous titania and silica samples exhibited varied photoactivities for dyes under visible light, due to the presence of the residual carbon species. Moreover, as a whole the titania sample enhanced the higher photocatalytic activity than the silica sample under both solar and visible light.

Visible-light photocatalytic activity of TiO2/ZnS nanocomposites prepared by homogeneous hydrolysis

2008 ◽  
Vol 110 (2-3) ◽  
pp. 370-378 ◽  
Author(s):  
Václav Štengl ◽  
Snejana Bakardjieva ◽  
Nataliya Murafa ◽  
Vendula Houšková ◽  
Kamil Lang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Photocatalytic Activity ◽  
Homogeneous Hydrolysis ◽  
Visible Light Photocatalytic

Impact of Rutile Fraction on TiO2 Visible-Light Absorption and Visible-Light-Induced Photocatalytic Activity

2018 ◽  
Author(s):  
David Maria Tobaldi ◽  
Luc Lajaunie ◽  
ana caetano ◽  
nejc rozman ◽  
Maria Paula Seabra ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Solid Phase ◽  
Diffraction Method ◽  
Band Alignment ◽  
Quantitative Phase Analysis ◽  
Transmission Microscopy ◽  
Visible Light Absorption ◽  
X Ray

<div>Titanium dioxide is by far the most utilised semiconductor material for photocatalytic applications. Still, it is transparent to visible-light. Recently, it has been proved that a type-II band alignment for the rutile−anatase mixture would improve its visible-light absorption.</div><div>In this research paper we thoroughly characterised the real crystalline and amorphous phases of synthesised titanias – thermally treated at different temperatures to get distinct ratios of anatase-rutile-amorphous fraction – as well as that of three commercially available photocatalytic nano-TiO2. </div><div>The structural characterisation was done via advanced X-ray diffraction method, namely the Rietveld-RIR method, to attain a full quantitative phase analysis of the specimens. The microstructure was also investigated via an advanced X-ray method, the whole powder pattern modelling. These methods were validated combining advanced aberration-corrected scanning transmission microscopy and high-resolution electron energy-loss spectroscopy. The photocatalytic activity was assessed in the liquid- and gas-solid phase (employing rhodamine B and 4-chlorophenol, and isopropanol, respectively, as the organic substances to degrade) using a light source irradiating exclusively in the visible-range.</div><div>Optical spectroscopy showed that even a small fraction of rutile (2 wt%) is able to shift to lower energies the apparent optical band gap of an anatase-rutile mixed phase. But is this enough to attain a real photocatalytic activity promoted by merely visible-light?</div><div>We tried to give a reply to that question.</div><div>Photocatalytic activity results in the liquid-solid phase showed that a high surface hydroxylation led to specimen with superior visible light-induced catalytic activity (i.e. dye and ligand-to-metal charge transfer complexes sensitisation effects). That is: not photocatalysis <i>sensu-strictu</i>.</div><div>On the other hand, the gas-solid phase results showed that a higher amount of the rutile fraction (around 10 wt%), together with less recombination of the charge carriers, were more effective for an actual photocatalytic oxidation of isopropanol.</div>

Synthesis of Visible Light Responsive N Doped TiO2 Photocatalyst and its Enhanced Photocatalytic Activity

2015 ◽  
Vol 11 (4) ◽  
pp. 447-452 ◽  
Author(s):  
Yujie Zhao ◽  
Huayang Li ◽  
Hari Bala ◽  
Jingkuo Chen ◽  
Bowen Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light

Preparation of Carbon Coated FeWO4 and its Photocatalytic Activity Under Visible Light~!2008-10-27~!2008-11-26~!2008-12-31~!

2010 ◽  
Vol 2 (1) ◽  
pp. 56-59 ◽  
Author(s):  
Hany H. Abdel Ghafar ◽  
Michio Inagaki ◽  
Tomoki Tsumura ◽  
Masahiro Toyoda
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Carbon Coated
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