Effects of pH Value and Water Content of Sol on TiO2 Photocatalytic Activity Prepared by SAS

2013 ◽  
Vol 774-776 ◽  
pp. 864-867
Author(s):  
Zai Feng Shi ◽  
Su Min Zhang ◽  
Su Guo
Keyword(s):  
Methylene Blue ◽  
Particle Size ◽  
Photocatalytic Activity ◽  
Citric Acid ◽  
Water Content ◽  
Mass Fraction ◽  
Ph Value ◽  
Sol Gel ◽  
Raw Material ◽  
Effects Of Ph

To investigate the effects of sol pH value and water content on photocatalytic activity of TiO2 prepared with sol-gel auto-igniting synthesis (SAS) method, TiO(NO3)2 was prepared with TiCl4 as raw material and used as precursor of TiO2. By changing sol pH value and water content, different TiO2 powders were prepared and characterized with XRD, SEM and photodegradation of methylene blue (MB). Results indicated that TiO2 presented the highest photocatalytic activity while sol pH value and mass fraction of water were adjusted to 7 and 50% respectively while the mole ratio of n (TiCl4): n (citric acid): n (ammonium nitrate) was fixed as 1: 1: 3. The TiO2 powders were confirmed as loose and porous anatase type with particle size of 15 nm by SEM and XRD.

Preparation of Fe3+/Ag+ Co-Doped Nanometer TiO2 Photocatalyst with Sol - Gel Auto-Igniting Method

2011 ◽  
Vol 399-401 ◽  
pp. 1721-1724
Author(s):  
Zai Feng Shi ◽  
Shu Guo
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Water Samples ◽  
Sol Gel ◽  
Raw Material ◽  
Molar Ratio ◽  
Mercury Lamp ◽  
Tio2 Powder ◽  
Photodegradation Rate ◽  
Co Doped

To study the preparation of Fe3+/Ag+ co-doped TiO2 photocatalyst with sol-gel auto-igniting method, TiO2 powder was prepared with TiCl4 as raw material and the photocatalytic activity of doped TiO2 was examined with methylene blue (MB) as water samples, and a 15w low pressure mercury lamp as light source. Results showed that: the TiO2 co-doped with 0.02% (molar ratio) of Fe3+ and 0.5% (molar ratio) of Ag+ gives the highest photocatalytic activity. The according photodegradation rate constant of MB is 1.33 and 1.10 times of that with TiO2 and Fe/TiO2 separately.

scholarly journals The Effect of Acidity and Aging Time in The Synthesis of Al(OH)3 from The Anodized-waste with a Sol-Gel Method

2019 ◽  
Vol 8 (3) ◽  
pp. 232-238
Author(s):  
Sri Wardhani ◽  
◽  
Danar Purwonugroho ◽  
Deka Permatasari ◽  
Darjito Darjito ◽  
...  
Keyword(s):  
Particle Size ◽  
Aging Time ◽  
Ph Value ◽  
Sol Gel ◽  
Powder Xrd ◽  
Raw Material ◽  
Gel Method ◽  
Sol Gel Method ◽  
D Values ◽  
Particle Size Characterization

Synthesis of alumina has been carried out by utilizing anodized waste as raw material. Anodized waste is a by-product of metal anodizing processes such as aluminium. This study aims to determine the effect of acidity (pH) and aging time on the mass of Al(OH)3 and the property of Al(OH)3 as well as Al2O3 that produced. Anodized waste was deposited into Al(OH)3 and then purified. Alumina synthesized by the sol-gel method with pH variations of 7, 8, 9, and 10 and aging times of 24, 48, and 72 hours. The Al(OH)3, which has been produced, was characterized by PSA and powder XRD spectrophotometer. The results showed that the synthesis of Al(OH)3 was influenced by pH and aging time. It affects the yield and particle size of Al(OH)3. The optimum condition of the synthesis was pH 7 and aging time of 24 hours with yield of 1.85 grams. Characterization by PSA at a current diameter of 90% indicate that higher pH value and longer aging time produces smaller particle size. Characterization by powder XRD shows that the Al(OH)3 has gibbsite crystal phase with d values of 3.360, 3.217, 2.252, 2.029, and 1.649 Å.

scholarly journals Synthesis of Silver Doped Titanium Dioxide by Wet-Ball Milling Sol–Gel Method for Antibacterial Application

2021 ◽  
Vol 333 ◽  
pp. 11002
Author(s):  
Tippabust Eksangsri ◽  
Chaweewan Sapcharoenkun ◽  
Siripond Phromma
Keyword(s):  
Methylene Blue ◽  
Particle Size ◽  
Antibacterial Activity ◽  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Surface Area ◽  
Degradation Rate ◽  
Sol Gel ◽  
Methylene Blue Degradation ◽  
Doped Titanium Dioxide

Titanium dioxide (TiO2) has been extensively studied as photo-catalyst for water treatment, air purification and antibacterial applications due to its challenging properties such as chemical stability, environmental friendly and strong photocatalytic activity. However, the limitation of TiO2 on its dependent to ultraviolet radiation for photocatalytic activity is still aroused. In this study, silver doped titanium dioxide (Ag-TiO2) was synthesized by wet-ball milling sol–gel method (WBMS). Ag-TiO2 molar ratio was varied from 0% to 10% to study the effect of silver content on the synthesized Ag-TiO2 characteristics and the ability to apply on antibacterial applications. The objective of this work was to find an optimal concentration of Ag in Ag-TiO2. Characterization of the particle size, morphology, and surface area of synthesized Ag-TiO2 were discussed by techniques of transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET). Photocatalytic activity was investigated from degradation of methylene blue. Antibacterial activity was conducted by finding minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests performed on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) under dark condition and under visible light. The results demonstrated that the doping of Ag inhibited crystal growth of Ag-TiO2. The smallest particle size and the highest surface area were obtained from 5% Ag-TiO2. Also, it was found that methylene blue degradation rate increased to the highest number of 1.62x10−3 min−1 when Ag concentration reached 5%, and methylene blue degradation rate reduced when Ag concentration was higher than 5%. The antibacterial activity of Ag-TiO2 was better than TiO2. The optimal concentration of 3-5% Ag-TiO2 was observed from the MIC and MBC tests.

Studies on Photocatalytic Degradation of Methylene Blue by Eu3+/Gd3+ Co-Doped TiO2

2011 ◽  
Vol 80-81 ◽  
pp. 55-59
Author(s):  
Xu Dong Lu ◽  
Cheng Zhi Jiang ◽  
Xiao Hui Zhu
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Ph Value ◽  
Anatase Phase ◽  
Sol Gel ◽  
Gel Method ◽  
Grain Sizes ◽  
Co Doped

The 0.05%Gd3+ /0.4%Eu3+ co-doped TiO2 composite nanopowders have been prepared by sol-gel method and characterized by the techniques such as XRD, SEM/EDAX. The photocatalytic degradation of Methylene blue in aqueous solution was used as a probe reaction to evaluate their photocatalytic activity. The results show that the 0.05%Gd3+ /0.4%Eu3+ co-doped TiO2 are only structuresd by anatase phase with grain sizes of about 16nm at 540 °C for 4 h. The photocatalutic degradation of Methylene blue was 96.7% in 120 min of irradiation when the pH value was 9.

Storage Problems of Poplar Chips from Short Rotation Plantations with Special Emphasis on Fungal Development

2012 ◽  
Vol 8 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Zsuzsanna Horváth ◽  
Béla Marosvölgyi ◽  
Christine Idler ◽  
Ralf Pecenka ◽  
Hannes Lenz
Keyword(s):  
Particle Size ◽  
Health Risk ◽  
Dry Matter ◽  
Ph Value ◽  
Wood Chips ◽  
Raw Material ◽  
Special Focus ◽  
Fungal Development ◽  
Short Rotation ◽  
Fungal Particles

Abstract - There are several problems in storing wood chips freshly harvested from short rotation plantations, which result in quality losses as well as in dry matter and energy losses. The factors influencing the degradation of raw material are examined in this paper with special focus on fungal development. An excessive growth of fungi is connected to dry matter losses and also to an increased health risk during raw material handling. The following factors were measured during 6 months storage of poplar wood chips depending on particle size: box temperature, moisture content, pH-value, appearance of fungi in the storage and the concentration of fungal particles in the air. The results show a close connection between particle size, temperature and attack of fungi. During the storage mesophilic and termophilic species of the genera Alternaria, Aspergillus, Cladosporium, Mucor and Penicillium appeared. The concentration of fungal particles is the highest for fine chips and decreases in bigger particles. There was a special focus on the investigation of the properties of coarse chips (G 50), which represent a good compromise between handling, storage losses and health risk due to fungal development.

Photocatalytic Degradation of Methylene Blue by NiO Thin Films under Solar Light Irradiation

2019 ◽  
Vol 56 ◽  
pp. 152-157 ◽  
Author(s):  
Abdelouahab Noua ◽  
Hichem Farh ◽  
Rebai Guemini ◽  
Oussama Zaoui ◽  
Tarek Diab Ounis ◽  
...  
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Visible Region ◽  
Optical Transmittance ◽  
Dip Coating ◽  
Light Irradiation ◽  
Solar Light ◽  
Solar Light Irradiation

Nickel oxide (NiO) thin films were successfully deposited by sol-gel dip-coating method on glass substrates. The structural, morphological and optical properties in addition to the photocatalytic activity of the prepared films were investigated. The results show that the films have a polycrystalline NiO cubic structure with dense NiO grains and average optical transmittance in the visible region. The photocatalytic properties of the films were studied through the degradation of methylene blue and 89% of degradation was achieved for 4.5h of solar light irradiation exposure which indicates the capability of NiO photocatalytic activity.

Effect of wood acidity and catalyst on UF resin gel time

Holzforschung ◽  
2004 ◽  
Vol 58 (4) ◽  
pp. 408-412 ◽  
Author(s):  
C. Xing ◽  
S.Y. Zhang ◽  
J. Deng
Keyword(s):  
Ph Value ◽  
Raw Materials ◽  
Urea Formaldehyde ◽  
Acid Catalyst ◽  
Buffering Capacity ◽  
Raw Material ◽  
Gel Time ◽  
Uf Resin ◽  
Effects Of Ph ◽  
Fiber Materials

Abstract Knowledge of pH and buffering capacity of raw fiber materials is important for understanding the effects of raw material on the curing rate of urea formaldehyde (UF) resin, used for panel manufacturing, especially with some less-desirable wood materials such as bark, top, and commercial thinnings. The effects of pH and buffering capacity as well as catalyst content on the gel time of UF resin were investigated. The results obtained from this study indicate that bark has a lower pH value as well as higher acid and alkaline buffering capacities than wood of the same species due to their extractives. The pH values of the raw fiber materials studied decrease with increased absolute and relative acid buffering capacity due to the increased absolute acidity mass in the solution. At lower levels of added catalyst, the effect of raw material pH on UF resin gel time is significant, while it is insignificant at higher catalyst contents. This may be due to the acidity of wood, which is the main acid catalyst source of the mixture at lower levels of added catalyst, while at higher levels, catalyst is the main source. With higher catalyst contents, all studied raw materials mixed with UF resin result in a longer gel time than does UF resin alone.

scholarly journals Visible-enhanced photocatalytic performance of CuWO4/WO3 hetero-structures: incorporation of plasmonic Ag nanostructures

2018 ◽  
Vol 42 (13) ◽  
pp. 11109-11116 ◽  
Author(s):  
R. Salimi ◽  
A. A. Sabbagh Alvani ◽  
N. Naseri ◽  
S. F. Du ◽  
D. Poelman
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Light Irradiation ◽  
Photo Degradation ◽  
Gel Method ◽  
Sol Gel Method

A new plasmonic Ag hybridized CuWO4/WO3 heterostructured nanocomposite was successfully synthesized via a ligand-assisted sol gel method and the photocatalytic activity was evaluated by photo-degradation of methylene blue (MB) under visible light irradiation.

scholarly journals Solvent-Free Process for the Development of Photocatalytic Membranes

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4481 ◽  
Author(s):  
Rosa M. Huertas ◽  
Maria C. Fraga ◽  
João G. Crespo ◽  
Vanessa J. Pereira
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Ceramic Membranes ◽  
High Photocatalytic Activity ◽  
Solvent Free ◽  
Narrow Pore Size Distribution ◽  
Free Process ◽  
Solvent Free Conditions ◽  
Bacteria And Fungi

This work described a new sustainable method for the fabrication of ceramic membranes with high photocatalytic activity, through a simple sol-gel route. The photocatalytic surfaces, prepared at low temperature and under solvent-free conditions, exhibited a narrow pore size distribution and homogeneity without cracks. These surfaces have shown a highly efficient and reproducible behavior for the degradation of methylene blue. Given their characterization results, the microfiltration photocatalytic membranes produced in this study using solvent-free conditions are expected to effectively retain microorganisms, such as bacteria and fungi that could then be inactivated by photocatalysis.

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