scholarly journals Effect of Calcination Conditions on the Properties and Photoactivity of TiO2 Modified with Biuret

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1546
Author(s):  
Aleksandra Piątkowska ◽  
Sylwia Mozia
Keyword(s):  
Photocatalytic Activity ◽  
Rutile Phase ◽  
Tio2 Photocatalysts ◽  
Wet Impregnation ◽  
Simulated Solar Light ◽  
Air Atmosphere ◽  
Technology Process ◽  
C And N ◽  
Calcination Method ◽  
Metal Doped

A simple wet impregnation-calcination method was used to obtain a series of novel non-metal doped TiO2 photocatalysts. Biuret was applied as C and N source, while raw titanium dioxide derived from sulfate technology process was used as TiO2 and S source. The influence of the modification with biuret and the effect of the atmosphere (air or argon) and temperature (500–800 °C) of calcination on the physicochemical properties and photocatalytic activity of the photocatalysts towards ketoprofen decomposition under simulated solar light was investigated. Moreover, selected photocatalysts were applied for ketoprofen photodecomposition under visible and UV irradiation. Crucial features affecting the photocatalytic activity were the anatase to rutile phase ratio, anatase crystallites size and non-metals content. The obtained photocatalysts revealed improved activity in the photocatalytic ketoprofen decomposition compared to the crude TiO2. The best photoactivity under all irradiation types exhibited the photocatalyst calcined in the air atmosphere at 600 °C, composed of 96.4% of anatase with 23 nm crystallites, and containing 0.11 wt% of C, 0.05 wt% of N and 0.77 wt% of S.

Characterization and Photocatalytic Properties of Transition Metal Doped TiO2 and Nanocomposite TiO2 Powders Synthesized by Mechanical Alloying

2007 ◽  
Vol 119 ◽  
pp. 195-198
Author(s):  
Dong Hyun Kim ◽  
Ha Sung Park ◽  
Jae Han Jho ◽  
Wheung Whoe Kim ◽  
Sun Jae Kim ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Photocatalytic Activity ◽  
Transition Metal ◽  
Mechanical Alloying ◽  
Rutile Phase ◽  
Alloyed Powder ◽  
Doped Tio2 ◽  
Average Grain Size ◽  
Xrd Patterns ◽  
Metal Doped

Transition metal doped TiO2 (Ni, Fe, Cu) and nanocomposite TiO2 powders with rutile phase were synthesized by mechanical alloying and heat treatment, and were characterized by XRD, TEM, UV-DRS, and PL (Photoluminescence). Photocatalytic activity was also investigated with the degradation rate of 4-chlorophenol and measured by total organic carbon analyzer. TEMEDP and XRD patterns showed that the transition metal doped powders (only alloyed powder) were in the form of rutile phase with the particle size of 20-30 nm. The average grain size of transition metal doped powders was in the range of less than 10 nm. However, after heat treatment, the alloyed powder formed composite of the titanate and rutile phase. The UV-DRS and PL investigation showed that Ni doped 8 wt% nanocomposite TiO2 had the higher wavelength range (600-660 nm) (2.0-1.9 eV) than that of the commercial P-25 powder(380-400 nm) by Degussa Co. indicating that the Ni 8 wt% doped nanocomposite TiO2 shifted the absorption into the visible light region and thus, enhanced the photocatalytic activity. Further, these results agreed well with TOC investigation. Formation of titanate in transition metal doped TiO2 due to heat treatment was found to control the grain growth of nano-sized TiO2 and to enhance its thermal stability at high temperature.

Preparation of Nano-Sized TiO2 Photocatalysts by a Multi-Gelation Method and Their Application to the Degradation of 2-Propanol Diluted in Water

2005 ◽  
Vol 486-487 ◽  
pp. 93-96
Author(s):  
B. Neppolian ◽  
Hiromi Yamashita ◽  
Yusuke Okada ◽  
H. Nishijima ◽  
Masakazu Anpo
Keyword(s):  
Phase Transition ◽  
Particle Size ◽  
Photocatalytic Activity ◽  
Phase Composition ◽  
Pore Diameter ◽  
Rutile Phase ◽  
Tio2 Photocatalysts ◽  
Tio2 Particles ◽  
Control Of Parameters ◽  
Ph Swing

TiO2 photocatalysts prepared by a novel multi-gelation method showed good photocatalytic activity for the degradation of 2-propanol diluted in water by the control of parameters such as particle size, surface area, crystallinity, pore-volume, pore-diameter as well as anatase and rutile phase composition by changing the number of pH swings during preparation. In particular, with this method the phase transition from anatase to rutile at higher pH swing times can be controlled and high purity and uniformity of the TiO2 particles which leads to higher photocatalytic activity of the particles can be achieved. From our experimental results, it has been observed that TiO2 catalysts prepared by this unique multi-gelation method, i.e., adopting variations in the pH swing, significantly shows higher photocatalytic activity for the degradation of 2- propanol diluted in water. It can be considered a viable alternative over existing commercial methods for the preparation of photofunctional catalysts.

scholarly journals Enhanced Photocatalytic Activity of La3+ doped Bicrystalline Titania Prepared via Combustion method for the Degradation of Cationic dye Under Solar Illumination

2018 ◽  
Vol 13 (1) ◽  
pp. 119 ◽  
Author(s):  
Radhika R Nair ◽  
Mothi Krishna Mohan ◽  
Sunaja Devi
Keyword(s):  
Photocatalytic Activity ◽  
Dye Degradation ◽  
Combustion Method ◽  
Rutile Phase ◽  
Hydroxyl Groups ◽  
Cationic Dye ◽  
X Ray Diffraction ◽  
Tio2 Photocatalysts ◽  
Doped Tio2 ◽  
Physico Chemical

La3+ doped TiO2 photocatalysts were successfully synthesized by combustion method in the presence of urea and were characterized by various physico-chemical techniques. Further, the photocatalytic performance of the synthesized catalysts was monitored by photocatalytic degradation of synthetic cationic dye-Methylene Blue (MB) under solar illumination. The bicrystalline phase of anatase and rutile was confirmed by X-ray diffraction analysis. Moreover, the transformation from anatase to rutile phase proceeds at a slower rate in the La3+ doped TiO2 catalysts. Effective separation of charge carriers, a synergistic effect in the bicrystalline framework of anatase and rutile, smaller crystallite size, and higher concentration of surface adsorbed hydroxyl groups helped these catalysts to show improved activity for the dye degradation. Copyright © 2018 BCREC Group. All rights reservedReceived: 28th July 2017; Revised: 19th October 2017; Accepted: 30th October 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018How to Cite: Nair, R.R., Mohan, M.K., Sunajadevi, K.R. (2018). Enhanced Photocatalytic Activity of La3+ doped Bicrystalline Titania Prepared via Combustion method for the Degradation of Cationic dye Under Solar Illumination. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1): 119-126 (doi:10.9767/bcrec.13.1.1427.119-126) 

scholarly journals Photocatalytic Degradation of Remazol Brilliant Blue R and Remazol Yellow FG using TiO2 doped Cd, Co, Mn

2021 ◽  
Vol 16 (4) ◽  
pp. 804-815
Author(s):  
Candra Purnawan ◽  
Sayekti Wahyuningsih ◽  
Oktaviani Nur Aniza ◽  
Octaria Priwidya Sari
Keyword(s):  
Photocatalytic Activity ◽  
Metal Ion ◽  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
Brilliant Blue ◽  
Bandgap Energy ◽  
X Ray ◽  
Remazol Brilliant Blue R ◽  
Metal Doped

TiO2 and TiO2 doped Cd, Co, Mn (TiO2-M) were synthesized with a sol-gel method, and the photocatalytic activity of Remazol Brilliant Blue R and Remazol Yellow FG has been conducted. TiO2-M (Cd, Co, Mn) was synthesized with the mol Ti:M ratio of 3:1, and the materials were calcined at 300, 400, and 500 °C. The materials were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX), and UV-Vis Reflectance. The XRD result shows that at the temperature of 300 °C TiO2 and TiO2-M formed tend to be amorphous. At 400 °C the anatase phase is formed, while at 500 °C the rutile phase begins to form. And overall, the crystallinity of TiO2 is higher than metal-doped TiO2. The UV-Vis Reflectance result showed that the bandgap energy of all doping materials (TiO2-M) decreased. The larger the metal ion radius of dopant, the larger the crystal size obtained  and then the higher the bandgap obtained. The results of SEM-EDX showed that the morphology of TiO2 was spherical and regular, whereas the morphology of TiO2-M had a smoother surface due to the influence of metal doping. Photocatalytic activity of TiO2-M on Remazol Brilliant Blue R and Remazol Yellow FG was greater than TiO2. The optimum pH of the solution was obtained at pH 5 and the optimum catalyst phase was obtained at the anatase phase. The percentages degradation for 30 min of Remazol Brilliant Blue R were 67.34% (TiO2), 92.12% (TiO2-Co), 85.47% (TiO2-Mn), and 83.91% (TiO2-Cd), while for Remazol Yellow FG they were 58.84% (TiO2), 74.61% (TiO2-Co), 67.93% (TiO2-Mn) and 64.19% (TiO2-Cd), respectively. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Photocatalytic Hydrogen Evolution over Pt/Co-TiO2 Photocatalysts

2020 ◽  
Vol 01 ◽  
Author(s):  
S. Akel ◽  
R. Dillert ◽  
D.W. Bahnemann
Keyword(s):  
Photocatalytic Activity ◽  
Band Gap ◽  
Hydrogen Evolution ◽  
Molecular Hydrogen ◽  
Hydrogen Generation ◽  
Solar Light ◽  
Tio2 Photocatalysts ◽  
Photocatalytic Hydrogen Evolution ◽  
Doped Tio2 ◽  
Simulated Solar Light

Aims: cobalt doped TiO2 composites were synthesized with the aim to decrease the TiO2 band gap which results in enhanced visible absorption and then loaded with 1 wt.% of platinum for promoting the formation of molecular hydrogen. Background: Controversial results of the cobalt-based compounds create doubts about the photocatalytic activity of the cobalt doped TiO2 materials. Thus, cobalt doped TiO2 composites were synthesized, and the photocatalytic activity was checked for the hydrogen generation. Objective: The objective of this study is the synthesis of photocatalysts that are highly active for the photocatalytic hydrogen evolution. Methods: The TiO2 and Co-TiO2 photocatalysts were synthesized using two different methods that are reflux and hydrothermal synthesis. Additionally, The Pt deposition on the prepared TiO2 and Co-TiO2 catalysts (1 wt.% Pt) was performed by the photoplatinization method. Result: The results showed that the reduction of protons over bare TiO2 and Co-TiO2 materials is possible from the thermodynamic point of view. The evolution of molecular hydrogen from aqueous methanol employing 1 wt.% platinum loaded on 0.5 wt.% Co-TiO2 photocatalysts under simulated solar light irradiation was investigated. The platinized CoTiO2 composites along with the platinized TiO2 samples have shown high photocatalytic hydrogen evolution. Higher hydrogen evolution rates were determined in the presence of all platinized materials, and a maximum of 317 μmol h-1 is observed on a Pt/Co-TiO2 photocatalyst prepared by a hydrothermal method. Conclusion: EPR results confirmed that the defects observed in the sample prepared within the hydrothermal processing were in the surface and have better crystallinity, while the defects detected on the samples prepared by reflux synthesis were less crystalline. The nature of semiconductor materials was explored through the determination of the flatband potential using the Mott–Schottky equation. The Mott−Schottky analysis of electrochemical impedance measurements showed that all semiconductors were n-type semiconductors and that cobalt doping induces impurity level within the band gap of TiO2. The experimental results of photocatalytic hydrogen generation from methanol-reforming showed that the Co- doping does not affect the photocatalytic activity of both Pt/Co-TiO2 catalysts. Despite that, the Pt/Co-TiO2-HT was the best photocatalyst under simulated solar light and show a maximum hydrogen evolution rate of 317 ± 44 μmol h-1. Other: Based on the experimental results, a possible mechanism for the continuous photocatalytic activity of Pt/Co-TiO2 photocatalysts under simulated solar light is proposed.

scholarly journals Unexpected Link between the Template Purification Solvent and the Structure of Titanium Dioxide Hollow Spheres

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 112
Author(s):  
Tamás Gyulavári ◽  
Kata Kovács ◽  
Klára Magyari ◽  
Kornélia Baán ◽  
Anna Szabó ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Phase Composition ◽  
Anatase Phase ◽  
Hollow Spheres ◽  
Rutile Phase ◽  
Carbon Sphere ◽  
Carbon Spheres ◽  
Carbonate Species ◽  
Determining Factor

Carbon spheres were applied as templates to synthesize titanium dioxide hollow spheres. The templates were purified with either ethanol or acetone, and the effects of this treatment on the properties of the resulting titania were investigated. The photocatalytic activity of the catalysts was measured via the decomposition of phenol model pollutant under visible light irradiation. It was found that the solvent used for the purification of the carbon spheres had a surprisingly large impact on the crystal phase composition, morphology, and photocatalytic activity. Using ethanol resulted in a predominantly rutile phase titanium dioxide with regular morphology and higher photocatalytic activity (r0,phenol = 3.9 × 10−9 M∙s−1) than that containing mainly anatase phase prepared using acetone (r0,phenol = 1.2 × 10−9 M∙s−1), surpassing the photocatalytic activity of all investigated references. Based on infrared spectroscopy measurements, it was found that the carbon sphere templates had different surface properties that could result in the appearance of carbonate species in the titania lattice. The presence or absence of these species was found to be the determining factor in the development of the titania’s properties.

The influence of the local structure of Fe(III) on the photocatalytic activity of doped TiO2 photocatalysts—An EXAFS, XPS and Mössbauer spectroscopic study

2011 ◽  
Vol 103 (1-2) ◽  
pp. 232-239 ◽  
Author(s):  
Éva G. Bajnóczi ◽  
Nándor Balázs ◽  
Károly Mogyorósi ◽  
Dávid F. Srankó ◽  
Zsolt Pap ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Spectroscopic Study ◽  
Local Structure ◽  
Tio2 Photocatalysts ◽  
Doped Tio2

scholarly journals C-,N- and S-Doped TiO2 Photocatalysts: A Review

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 144
Author(s):  
Aleksandra Piątkowska ◽  
Magdalena Janus ◽  
Kacper Szymański ◽  
Sylwia Mozia
Keyword(s):  
Carbon Dioxide Reduction ◽  
Air Purification ◽  
Lithium Storage ◽  
Tio2 Photocatalysts ◽  
Doped Tio2 ◽  
Preparation Conditions ◽  
Production Of Hydrogen ◽  
Methods Of Synthesis ◽  
Metal Doped ◽  
Inactivation Of Bacteria

This article presents an overview of the reports on the doping of TiO2 with carbon, nitrogen, and sulfur, including single, co-, and tri-doping. A comparison of the properties of the photocatalysts synthesized from various precursors of TiO2 and C, N, or S dopants is summarized. Selected methods of synthesis of the non-metal doped TiO2 are also described. Furthermore, the influence of the preparation conditions on the doping mode (interstitial or substitutional) with reference to various types of the modified TiO2 is summarized. The mechanisms of photocatalysis for the different modes of the non-metal doping are also discussed. Moreover, selected applications of the non-metal doped TiO2 photocatalysts are shown, including the removal of organic compounds from water/wastewater, air purification, production of hydrogen, lithium storage, inactivation of bacteria, or carbon dioxide reduction.

scholarly journals Fabrication, N-doping Mechanism and Evaluation of N-doped TiO2 Thin Films Based on Laser Ablation Method

2009 ◽  
Vol 2 (1) ◽  
pp. 17-23 ◽  
Author(s):  
S. Somekawa ◽  
Y. Kusumoto ◽  
H. Yang ◽  
M. Abdulla-Al-Mamun ◽  
B. Ahmmad
Keyword(s):  
Crystal Structure ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Laser Ablation ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Laser Ablation Method ◽  
Dye Decomposition ◽  
N Doping ◽  
Keywords Laser

The relation among the change of the crystal structure, the amount of doped N and the photocatalytic activity for the decomposition of methylene blue was studied. The N-doping was promoted by the change of the crystal structure from the rutile phase to the anatase phase. The photocatalytic activity for the decomposition of methylene blue was enhanced by an increase in the amount of anatase crystals and doped N. Keywords: Laser ablation; N-doping process; Crystal change; N-doped TiO2 thin film; Dye decomposition. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.2992        J. Sci. Res. 2 (1), 17-23 (2010) 

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