scholarly journals Comparative Study of Synthesis Parameters of Nanoporous Titania Particles to Improve Structural Properties and Photocatalytic Activity

2021 ◽  
Author(s):  
Zahra Hassankhani-Majd ◽  
Mansoor Anbia
Keyword(s):  
Methylene Blue ◽  
Particle Size ◽  
Photocatalytic Activity ◽  
Freeze Drying ◽  
Chelating Agent ◽  
Nanoporous Materials ◽  
Hydrolysis Method ◽  
Surface Areas ◽  
Synthesis Parameters ◽  
Particle Shapes

Abstract Nanoporous materials have been widely used in many fields. However, their synthesis with uniform particle shapes, pore sizes, pore volumes, and surface areas remains a considerable challenge. Thus, choosing a suitable controllable method for synthesizing nanoporous materials is crucial to obtain appropriate properties. Herein, nanoporous titania particles (NPTPs) were prepared via the hydrothermal. This study investigated how the synthesis parameters such as the type of chelating agent, the hydrolysis method, and the drying technique affected the properties of NPTPs. The synthesis NPTPs were characterized by XRD, FESEM, and BET. The results demonstrated that when acetylacetone (ACAC) (as the chelating agent), the spray-hydrolysis (SH) method, and the freeze-drying (FD) technique were used, NPTPs achieved a more uniform particle shape, a smaller particle size, a larger pore size, a larger pore volume, and a higher surface area. Ultimately, the photocatalytic degradation (PCD) of methylene blue (MB) was examined using improved NPTPs.

Effect of Iron (III)-Doping on the Photocatalytic Activity of Titanium Dioxide Catalysts for Methylene Blue Degradation

2011 ◽  
Vol 117-119 ◽  
pp. 1088-1091
Author(s):  
Wen Churng Lin ◽  
Rui Liu ◽  
Wein Duo Yang
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Specific Surface ◽  
Effective Means ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Surface Areas ◽  
Bet Specific Surface Area ◽  
Vis Spectroscopy

Iron-doped TiO2 photocatalyst powders were prepared by the sol–gel method and characterized by Brunauer–Emmett–Teller (BET)-specific surface area, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Ultraviolet–Visible (UV-Vis) spectroscopy. Fe3+ doping in the TiO2 decreases the crystal grain size, increases the specific surface areas of powders, extends the absorption to visible light regions (400~500 nm), and lowers the photocatalytic activity for methylene blue (MB) degradation under UV irradiation. The photocatalytic degradation of MB in water was investigated as a function of the Fe3+ content in TiO2. It was found that under the irradiation of visible light, a small amount of Fe3+ dopant in TiO22 powders could obviously enhance the photocatalytic activity. When the Fe3+ content was in the range of 0.03–0.1 mol%, the photocatalytic activity of the samples was higher than that of undoped TiO2. Appropriate content of Fe-doping is an effective means to improve the photocatalytic activity of TiO2 for MB degradation under visible light irradiation.

scholarly journals Molten-Salt Flux Mediated Synthesis of ZnO-SnO2 Composites: Effects of Surface Areas and Crystallinities on Photocatalytic Activity

2020 ◽  
Author(s):  
Rachelle Austin ◽  
Feier Hou
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Surface Area ◽  
Salt Flux ◽  
Blue Dye ◽  
Synthetic Approach ◽  
Flux Synthesis ◽  
Surface Areas ◽  
Photocatalytic Activities ◽  
Two Factors

In this study, ZnO-SnO2 composites were synthesized using flux synthesis, a synthetic approach different from previous studies, in which molten ZnCl2 acted both as a reactant and as the flux for the reaction. Their photocatalytic properties were measured for the degradation of the organic dye, methylene blue. It was found that as the temperatures of the synthesis increase, the specific surface areas of the ZnO-SnO2 composites decrease, which would decrease their photocatalytic activities due to decreased adsorption of the dye on the surface of the composites; while their crystallinity increases, which would increase their photocatalytic activities due to the smaller concentration of defects and thus improved mobility of the charge carriers. An interplay of those two factors affects their photocatalytic activities, with the composite with the highest photocatalytic activity degrading approximately 95% of the methylene blue dye within 10 minutes. By changing the temperature of the flux synthesis alone, the crystallinity and surface area of the ZnO-SnO2 composite can be changed, which provides a possible way to obtain ZnO-SnO2 composites with relatively high crystallinity and surface area to maximize their photocatalytic activity.

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.

scholarly journals Molten-Salt Flux Mediated Synthesis of ZnO-SnO2 Composites: Effects of Surface Areas and Crystallinities on Photocatalytic Activity

2020 ◽  
Author(s):  
Rachelle Austin ◽  
Feier Hou
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Surface Area ◽  
Salt Flux ◽  
Blue Dye ◽  
Synthetic Approach ◽  
Flux Synthesis ◽  
Surface Areas ◽  
Photocatalytic Activities ◽  
Two Factors

In this study, ZnO-SnO2 composites were synthesized using flux synthesis, a synthetic approach different from previous studies, in which molten ZnCl2 acted both as a reactant and as the flux for the reaction. Their photocatalytic properties were measured for the degradation of the organic dye, methylene blue. It was found that as the temperatures of the synthesis increase, the specific surface areas of the ZnO-SnO2 composites decrease, which would decrease their photocatalytic activities due to decreased adsorption of the dye on the surface of the composites; while their crystallinity increases, which would increase their photocatalytic activities due to the smaller concentration of defects and thus improved mobility of the charge carriers. An interplay of those two factors affects their photocatalytic activities, with the composite with the highest photocatalytic activity degrading approximately 95% of the methylene blue dye within 10 minutes. By changing the temperature of the flux synthesis alone, the crystallinity and surface area of the ZnO-SnO2 composite can be changed, which provides a possible way to obtain ZnO-SnO2 composites with relatively high crystallinity and surface area to maximize their photocatalytic activity.

scholarly journals Formation and Photocatalytic Activity of BaTiO3Nanocubes via Hydrothermal Process

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Xinrun Xiong ◽  
Ruoming Tian ◽  
Xi Lin ◽  
Dewei Chu ◽  
Sean Li
Keyword(s):  
Methylene Blue ◽  
Particle Size ◽  
Photocatalytic Activity ◽  
Reaction Time ◽  
Hydrothermal Process ◽  
Photocatalytic Decomposition ◽  
Photocatalytic Reaction ◽  
Photocatalytic Efficiency ◽  
Methylene Orange ◽  
Hydrothermal Approach

We reported a facile hydrothermal approach to synthesize BaTiO3nanocubes with controlled sizes for degradation of methylene blue (MB). The nanocubes with reaction time of 48 hours exhibited the highest photocatalytic efficiency, owing to their narrower size distribution and better crystallinity compared to those of 24 hours and, at the meantime, smaller particle size than those of 72 hours. This work also demonstrated the degradation of methylene orange (MO) using BaTiO3nanocubes synthesized for 48 hours. Compared with the removal of MB, BaTiO3had lower photocatalytic activity on MO, mainly due to the poorer absorption behavior of MO on the surface of BaTiO3nanocubes. The degradation efficiency for each photocatalytic reaction was calculated. The possible mechanism of the photocatalytic decomposition on MB has been addressed as well.

Synthesis of Fe-doped TiO2 nanotubes by hydrothermal method for photodegradation of methylene blue from aqueous solutions

2021 ◽  
Vol 11 (1) ◽  
pp. 30-37
Author(s):  
Hung Nguyen Van ◽  
Nhi Tran Thi Yen ◽  
Nghi Nguyen Huu ◽  
Nguyet Bui Thi Minh
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Hydrothermal Method ◽  
Tio2 Nanotubes ◽  
Kinetic Studies ◽  
Ferric Nitrate ◽  
Hydroxyl Groups ◽  
Doped Tio2 ◽  
Molar Ratios ◽  
Surface Areas

Fe-doped TiO2 nanotubes were prepared by hydrothermal method using ferric nitrate and commercial TiO2 powder. The obtained materials were characterized by means of XRD, TEM, BET, FT-IR and UV-Vis-DRS. The photocatalytic activity was evaluated based on photodegradation of methylene blue under visible light irradiation. The results show that Fe3+ ions might incorporate into the lattice of TiO2 nanotubes. Fe-doped TiO2 materials showed narrower band gap energies, higher specific surface areas, more hydroxyl groups on the surface and significantly improved photocatalytic activity. The optimum Fe doping at the molar ratios of Fe/Ti = 0.5% showed the highest photocatalytic activity and was 3.08 times higher than that of undoped TiO2. The kinetic studies showed the decomposition of MB followed pseudo first-order kinetics with the rate constant were determined kapp = 5.64×10-2 min−1.

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.

Piezoelectric catalytic, photocatalytic and adsorption capability and selectivity removal of various dyes and mixed dye wastewater by ZnO nanoparticles

2022 ◽  
pp. 1-19
Author(s):  
Shengnan Tang ◽  
Huajing Gao ◽  
Shifa Wang ◽  
Leiming Fang ◽  
Xiping Chen ◽  
...  
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Adsorption Capacity ◽  
Rhodamine B ◽  
Zno Nanoparticles ◽  
Chelating Agent ◽  
Catalytic Performance ◽  
Wet Chemistry ◽  
Dependent Behavior ◽  
Internal Mechanism

The C-O functional group decorated ZnO nanoparticles with high UV absorption and VIS/NIR reflectance were synthesized by a simple wet chemistry method using various chelating agents. This study attempts to explore the internal mechanism of the piezoelectric catalytic activity, photocatalytic activity and adsorption performance of ZnO nanoparticles. The phase purity, particle size, optical band gap and photocatalytic activity of ZnO nanoparticles showed strong chelating agent - dependent behavior. The ZnO nanoparticles prepared by using EDTA as a chelating agent exhibits smallest particle size, highest photocatalytic activity for the degradation of methyl orange, methylene blue and rhodamine B, high adsorption capacity for the adsorption of Congo red and high vibration-catalytic performance for the vibration degradation of rhodamine B. The synergies mechanism among piezoelectric catalysis, photocatalysis and adsorption capacity of ZnO nanoparticles are discussed on the basis of the experimental results.

scholarly journals Effects of Particle Size on the Structure and Photocatalytic Performance by Alkali-Treated TiO2

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 546 ◽  
Author(s):  
Danqi Li ◽  
Hongchen Song ◽  
Xia Meng ◽  
Tingting Shen ◽  
Jing Sun ◽  
...  
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Alkali Concentration ◽  
Hydrothermal Time ◽  
Surface Areas ◽  
Radical Trapping ◽  
Photogenerated Electrons ◽  
N2 Atmosphere ◽  
New Ideas

Particle size of nanomaterials has significant impact on their photocatalyst properties. In this paper, TiO2 nanoparticles with different crystalline sizes were prepared by adjusting the alkali-hydrothermal time (0–48 h). An annealing in N2 atmosphere after hydrothermal treatment caused TiO2 reduction and created defects, resulting in the visible light photocatalytic activity. The evolution of physicochemical properties along with the increase of hydrothermal time at a low alkali concentration has been revealed. Compared with other TiO2 samples, TiO2-24 showed higher photocatalytic activity toward degrading Rhodamine B and Sulfadiazine under visible light. The radical trapping and ESR experiments revealed that O2•- is the main reactive specie in TiO2-24. Large specific surface areas and rapid transfer of photogenerated electrons are responsible for enhancing photocatalytic activity. The above findings clearly demonstrate that particle size and surface oxygen defects can be regulated by alkali-hydrothermal method. This research will deepen the understanding of particle size on the nanomaterials performance and provide new ideas for designing efficient photocatalysts.

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