scholarly journals Synthesis and Characterization of CeO2-SiO2Nanoparticles by Microwave-Assisted Irradiation Method for Photocatalytic Oxidation of Methylene Blue Dye

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
R. M. Mohamed ◽  
E. S. Aazam
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Irradiation Time ◽  
High Surface ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
Microwave Assisted ◽  
Small Pore

CeO2-SiO2nanoparticles were synthesized for the first time by a facile microwave-assisted irradiation process. The effect of irradiation time of microwave was studied. The materials were characterized by N2adsorption, XRD, UV-vis/DR, and TEM. All solids showed mesoporous textures with high surface areas, relatively small pore size diameters, and large pore volume. The X-ray diffraction results indicated that the as-synthesized nanoparticles exhibited cubic CeO2without impurities and amorphous silica. The transmission electron microscopy (TEM) images revealed that the particle size of CeO2-SiO2nanoparticles, which were prepared by microwave method for 30 min irradiation times, was around 8 nm. The photocatalytic activities were evaluated by the decomposition of methylene blue dye under UV light irradiations. The results showed that the irradiation under the microwave produced CeO2-SiO2nanoparticles, which have the best crystallinity under a shorter irradiation time. This indicates that the introduction of the microwave really can save energy and time with faster kinetics of crystallization. The sample prepared by 30 min microwave irradiation time exhibited the highest photocatalytic activity. The photocatalytic activity of CeO2-SiO2nanoparticles, which were prepared by 30 min irradiation times was found to have better performance than commercial reference P25.

scholarly journals Photocatalytic Degradation of Methylene Blue by Fe/ZnO/SiO2Nanoparticles under Visiblelight

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
R. M. Mohamed ◽  
I. A. Mkhalid ◽  
E. S. Baeissa ◽  
M. A. Al-Rayyani
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Light Irradiation ◽  
Photocatalytic Oxidation ◽  
Catalyst Loading ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
Illumination Time

The photocatalytic activity of Fe/ZnO/SiO2catalysts under visible-light irradiation for the degradation of methylene blue was evaluated. The effect of pH, illumination time, amount of catalyst loaded, and initial dye concentration on the degradation efficiency of methylene blue was investigated. The results reveal that the optimum photocatalytic oxidation conditions of methylene blue are as follows:pH=4and illumination time is 30 min, the amount of catalyst loading is 0.075 g/L and 50 ppm methylene blue dye concentration. Under these conditions, the removal efficiency of methylene blue was 100%.

scholarly journals Nano-sized SnO2 Photocatalysts: Synthesis, Characterization and Their Application for the Degradation of Methylene Blue Dye

2016 ◽  
Vol 8 (3) ◽  
pp. 399-411 ◽  
Author(s):  
M. T. Uddin ◽  
Y. Sultana ◽  
M. A. Islam
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Uv Light ◽  
Irradiation Time ◽  
Sno2 Nanoparticles ◽  
Average Crystallite Size ◽  
Precipitation Method ◽  
Catalyst Loading ◽  
Blue Dye ◽  
Effect Of Ph

In the present study, tin oxide (SnO2) nanoparticles were prepared by precipitation method using tin tetrachloride (SnCl4) as precursor and ammonia solution as precipitating agent followed by calcination at 400 ºC for 2 h. As-prepared SnO2 particles were characterized by X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR). The powder XRD results revealed that the SnO2 nanoparticles had a typical tetragonal rutile (cassiterite) structure and the average crystallite size calculated by using the Debye –Scherrer equation was found to be approximately 5.1 nm. The photocatalytic activity of the as-prepared photocatalysts was investigated by degrading methylene blue (MB) dye. The effect of pH, catalyst loading and initial dye concentration on photocatalytic degradation was investigated. Results showed that the SnO2 nanoparticles represented excellent photocatalytic activity for the degradation of MB under UV light with 200 min of irradiation time. The results also showed that the pH of solution had a direct influence on the photocatalysis process and basic pH was favorable for the degradation of MB. The effect of pH on photocatalytic activity was explained with the help of zero point charge (pHpzc). Furthermore, the photocatalysts could be easily recycled without significant change in the catalytic activity.

Physical Properties of Fe3+/TiO2 Nanoparticles and Photocatalytic Disinfection of Foodborne Microorganisms

2018 ◽  
Vol 17 (3) ◽  
pp. 312-321
Author(s):  
Long Men ◽  
Zhan Ge ◽  
Sun Meng-Yun ◽  
Zhuang Hong ◽  
Wang Ran
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Physical Properties ◽  
Salmonella Typhimurium ◽  
Uv Light ◽  
Meat Products ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
Photocatalytic Disinfection

In this article, we studied the preparation of Fe3+/TiO2 nanoparticles and the photocatalytic disinfection effects of two typical foodborne microorganisms, a gram-negative bacterium (Salmonella typhimurium) and a gram-positive bacterium (Listeria monocytogenes), in meat products. The physical properties of Fe3+/TiO2 nanoparticles embedded with various levels of Fe3+ (0%–10%) and synthesized through an impregnation process were investigated using X-ray diffraction, transmission electron microscopy, and UV-vis spectrophotometer, and their photocatalytic activities were evaluated by measuring the degradation of methylene blue dye and the disinfection of foodborne pathogens S. typhimurium and L. monocytogenes under visible light and UV light. Fe3+ ions were found to be scattered across TiO2 surfaces or across TiO2 crystal lattices as microcrystals. However, the capacity for TiO2 nanoparticles to absorb visible light was significantly enhanced after they were embedded with.Fe3+/TiO2 nanoparticles with molar ratios (R) of Fe3+ to TiO2 of 0.001:1, 0.005:1, and 0.01:1 exhibited higher levels of methylene blue dye photocatalytic degradation and higher levels of foodborne pathogen photocatalytic disinfection than the TiO2 control. However, nanoparticles containing >1% Fe3+ exhibited lower levels of photocatalytic activity than the TiO2 control. Salmonella typhimurium was more resistant to the nano-Fe3+/TiO2 treatment than L. monocytogenes under visible and UV light conditions. These experiments demonstrate that embedding Fe3+ in TiO2 nanoparticles does not remarkably influence the TiO2 nanoparticle size or structure. Embedding appropriate levels of Fe3+ content (0.1%–1%) can enhance the photocatalytic activity of TiO2 nanoparticles.

scholarly journals Highly Porous and Ultra-Lightweight Aero-Ga2O3: Enhancement of Photocatalytic Activity by Noble Metals

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1985
Author(s):  
Irina Plesco ◽  
Vladimir Ciobanu ◽  
Tudor Braniste ◽  
Veaceslav Ursaki ◽  
Florian Rasch ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Noble Metals ◽  
Hybrid Structures ◽  
Blue Dye ◽  
Light Illumination ◽  
Methylene Blue Dye ◽  
Visible Light Illumination ◽  
New Type ◽  
Highly Porous

A new type of photocatalyst is proposed on the basis of aero-β-Ga2O3, which is a material constructed from a network of interconnected tetrapods with arms in the form of microtubes with nanometric walls. The aero-Ga2O3 material is obtained by annealing of aero-GaN fabricated by epitaxial growth on ZnO microtetrapods. The hybrid structures composed of aero-Ga2O3 functionalized with Au or Pt nanodots were tested for the photocatalytic degradation of methylene blue dye under UV or visible light illumination. The functionalization of aero-Ga2O3 with noble metals results in the enhancement of the photocatalytic performances of bare material, reaching the performances inherent to ZnO while gaining the advantage of the increased chemical stability. The mechanisms of enhancement of the photocatalytic properties by activating aero-Ga2O3 with noble metals are discussed to elucidate their potential for environmental applications.

Sequestration of methylene blue dye from aqueous solution using microwave assisted dragon fruit peel as adsorbent

2021 ◽  
pp. 101917
Author(s):  
Mohd Azmier Ahmad ◽  
Muhammad Aswar Eusoff ◽  
Kayode Adesina Adegoke ◽  
Olugbenga Solomon Bello
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
Fruit Peel ◽  
Microwave Assisted ◽  
Dragon Fruit
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