Sol-Gel Preparation, Characterization and Photocatalytic Activity of Nanostructured TiO2 Nanoparticles

2012 ◽  
Vol 1372 ◽  
Author(s):  
R. Carrera ◽  
S. Castillo
Keyword(s):  
Volatile Organic Compounds ◽  
Physicochemical Properties ◽  
Organic Compounds ◽  
Photocatalytic Oxidation ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Photocatalytic Decomposition ◽  
Volatile Organic ◽  
Gel Preparation

ABSTRACTTo establish a promising method for the purification of air containing volatile organic compounds, TiO2 nanoparticles with interesting physicochemical properties were prepared by the sol-gel method to perform the photocatalytic decomposition of acetaldehyde. The obtained samples were characterized by the x-ray diffraction -Rietveld refinement, transmission electron microscopy (TEM) and the Brunauer, Emmet and Teller (BET) model. According to the results, the sample that presented the highest activity (96.4%) in the photocatalytic oxidation of acetaldehyde was the one annealed at 200 °C. This material showed the presence of a mixture of the anatase (higher proportion) and brookite phases, nanometric crystal size (7.03 nm) and high surface area (189 m2g-1). The physicochemical properties present in the TiO2-P-200°C nanoparticles suggest that they may establish a photoassisted reaction process for air purification, in which volatile organic compounds are photocatalitically decomposed.

scholarly journals Selectivity of Tungsten Oxide Synthesized by Sol-Gel Method Towards Some Volatile Organic Compounds and Gaseous Materials in a Broad Range of Temperatures

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 523 ◽  
Author(s):  
Simonas Ramanavičius ◽  
Milda Petrulevičienė ◽  
Jurga Juodkazytė ◽  
Asta Grigucevičienė ◽  
Arūnas Ramanavičius
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Sol Gel ◽  
Temperature Dependent ◽  
Sensing Systems ◽  
Sensing Material ◽  
Operational Temperature ◽  
Volatile Organic ◽  
Different Gases

In this research, the investigation of sensing properties of non-stoichiometric WO3 (WO3−x) film towards some volatile organic compounds (VOC) (namely: Methanol, ethanol, isopropanol, acetone) and ammonia gas are reported. Sensors were tested at several temperatures within the interval ranging from a relatively low temperature of 60 up to 270 °C. Significant variation of selectivity, which depended on the operational temperature of sensor, was observed. Here, the reported WO3/WO3–x-based sensing material opens an avenue for the design of sensors with temperature-dependent sensitivity, which can be applied in the design of new gas- and/or VOC-sensing systems that are dedicated for the determination of particular gas- and/or VOC-based analyte concentration in the mixture of different gases and/or VOCs, using multivariate analysis of variance (MANOVA).

The rate of photocatalytic oxidation of aromatic volatile organic compounds in the gas-phase

2008 ◽  
Vol 42 (34) ◽  
pp. 7844-7850 ◽  
Author(s):  
Aikaterini K. Boulamanti ◽  
Christos A. Korologos ◽  
Constantine J. Philippopoulos
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Phase ◽  
Organic Compounds ◽  
Photocatalytic Oxidation ◽  
Volatile Organic

Study on spinel - typed catalyst NiCo2O4 for total oxidation of toluene

2021 ◽  
Vol 10 (4) ◽  
pp. 97-102
Author(s):  
Nhung Nguyen Hong ◽  
Hung Khong Manh ◽  
Thang Le Minh ◽  
Phuong Pham Thi Mai ◽  
Nam Chu Thi Hai
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Sol Gel ◽  
Total Oxidation ◽  
Gel Method ◽  
Sol Gel Method ◽  
Volatile Organic ◽  
Epr Experiments

Toluene is a component of volatile organic compounds which need to be converted into non-poisonous one. Thus, we study the spinel-typed catalyst as NiCo2O4 for total oxidation of toluene because the advantage of spinel catalyst is multi- defective. Based on the sol-gel method, the catalysts NiCo2O4 were successfully prepared with different ratios of Ni/Co. The characteristic properties of catalysts were evaluated by XRD, BET, H2-TPR and EPR experiments. Amongst these ratios, the catalyst with ratio Ni/Co as 0.5 had the best activity in the total oxidation of toluene, as 100% conversion reached at 250 oC.

scholarly journals Enhancement of Photocatalytic Oxidation of Glucose to Value-Added Chemicals on TiO2 Photocatalysts by A Zeolite (Type Y) Support and Metal Loading

Catalysts ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 423 ◽  
Author(s):  
Kamonchanok Roongraung ◽  
Surawut Chuangchote ◽  
Navadol Laosiripojana
Keyword(s):  
Formic Acid ◽  
Surface Area ◽  
Gluconic Acid ◽  
Photocatalytic Oxidation ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Value Added ◽  
Incipient Wetness Impregnation ◽  
Microwave Assisted

TiO2-based photocatalysts synthesized by the microwave-assisted sol-gel method was tested in the photocatalytic glucose conversion. Modifications of TiO2 with type-Y zeolite (ZeY) and metals (Ag, Cu, and Ag-Cu) were developed for increasing the dispersion of TiO2 nanoparticles and increasing the photocatalytic activity. Effects of the TiO2 dosage to zeolite ratio (i.e., TiO2/ZeY of 10, 20, 40, and 50 mol %) and the silica to alumina ratio in ZeY (i.e., SiO2:Al2O3 of 10, 100, and 500) were firstly studied. It was found that the specific surface area of TiO2/ZeY was 400–590 m2g−1, which was higher than that of pristine TiO2 (34.38 m2g−1). The good properties of 20%TiO2/ZeY photocatalyst, including smaller particles (13.27 nm) and high surface area, could achieve the highest photocatalytic glucose conversion (75%). Yields of gluconic acid, arabinose, xylitol, and formic acid obtained from 20%TiO2/ZeY were 9%, 26%, 4%, and 35%, respectively. For the effect of the silica to alumina ratio, the highest glucose conversion was obtained from SiO2:Al2O3 ratio of 100. Interestingly, it was found that the SiO2:Al2O3 ratio affected the selectivity of carboxylic products (gluconic acid and formic acid). At a low ratio of silica to alumina (SiO2:Al2O3 = 10), higher selectivity of the carboxylic products (gluconic acid = 29% and formic acid = 32%) was obtained (compared with other higher ratios). TiO2/ZeY was further loaded by metals using the microwave-assisted incipient wetness impregnation technique. The highest glucose conversion of 96.9 % was obtained from 1 wt. % Ag-TiO2 (40%)/ZeY. Furthermore, the bimetallic Ag-Cu-loaded TiO2/ZeY presented the highest xylitol yield of 12.93%.

Correlations between Molecular Descriptors from Various Volatile Organic Compounds and Photocatalytic Oxidation Kinetic Constants

2013 ◽  
Vol 11 (2) ◽  
pp. 799-813 ◽  
Author(s):  
Cécile Raillard ◽  
Valérie Héquet ◽  
Bifen Gao ◽  
Heyok Choi ◽  
Dionysios D. Dionysiou ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Photocatalytic Oxidation ◽  
Molecular Descriptors ◽  
Equilibrium Constants ◽  
Oxidation Kinetic ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Degradation Rates ◽  
Volatile Organic

Abstract The photocatalytic oxidation of seven typical indoor volatile organic compounds (VOCs) is experimentally investigated using novel nanocrystalline TiO2 dip-coated catalysts. Not only the role of hydrophilicity of the reactants but also other physico-chemical properties and molecular descriptors are studied and related to kinetic and equilibrium constants. The main objective of this work consists in establishing simple relationships that will be useful to deepen the understanding of gas-phase heterogeneous photocatalytic mechanisms and for the prediction of degradation rates of these VOCs using an indoor air treatment process.

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