scholarly journals Application of Floating TiO2 Photocatalyst for Methylene Blue Decomposition and Salmonella Typhimurium Inactivation

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 794
Author(s):  
Marius Urbonavicius ◽  
Sarunas Varnagiris ◽  
Sandra Sakalauskaite ◽  
Emilija Demikyte ◽  
Simona Tuckute ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Salmonella Typhimurium ◽  
Blue Dye ◽  
Tio2 Films ◽  
Bacterial Inactivation ◽  
X Ray ◽  
Practical Applications ◽  
Detailed Surface ◽  
Decomposition Experiments ◽  
Nanocrystalline Anatase Tio2

The growing level of wastewater as well as pollution of freshwater by various bacteria are essential worldwide issues which have to be solved. In this contribution, nanocrystalline anatase TiO2 films deposited by magnetron sputtering on high-density polystyrene (HDPE) beads were applied as floating photocatalysts for Salmonella Typhimurium bacterial inactivation in water for the first time. Additionally, the photocatalytic degradation of methylene blue dye in the presence of HDPE beads with TiO2 film under UV-B irradiation was investigated. The suitability to adopt such floating photocatalyst structures for practical applications was tested in cycling experiments. The detailed surface morphology, crystal structure, elemental mapping, surface chemical composition and bond analysis of deposited TiO2 films were investigated by scanning electron microscope, X-ray diffractometer and X-ray photoelectron spectroscope techniques. The bacterial viability as well as MB decomposition experiments showed promising results by demonstrating that 6% of bacterial colonies were formed after the first run and only about 1% after the next four runs, which is an appropriate outcome for practical applications. NPN uptake results showed that the permeability of the outer membrane was significantly increased as well.

Water Disinfection Using Fe3+ and N-Doped 3SnO2/TiO2 Thin Films Coated on Glass Fibers

2010 ◽  
Vol 148-149 ◽  
pp. 1501-1506 ◽  
Author(s):  
Lek Sikong ◽  
Peerawas Kongsong ◽  
Vishnu Rachpech
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Glass Fibers ◽  
Composite Films ◽  
Water Disinfection ◽  
Blue Dye ◽  
Tio2 Films ◽  
Methylene Blue Dye ◽  
Bacterial Inactivation ◽  
E Coli

The water disinfection efficiency of Fe3+ and N-doped 3SnO2/TiO2 composite and undoped films was investigated. The water containing E. coli with an initial concentration of 103 CFU/ml was treated by a photocatalytic reactor filled with 60 g of glass fibers coated with the catalytic films for 1-5 circulated cycles. The number of survival bacteria after treatment was evaluated with spread plate techniques. Furthermore, the photocatalytic reaction on degradation of methylene blue dye solution was also investigated in order to observe the correlation between the result of bacteria inactivation of the prepared films and that of photocatalytic activity on methylene blue degradation. It reveals that N-doping in the TiO2 composite films results in shifting absorption wavelength towards visible light, narrowing the energy band gap and acts as photo-generated electrons trapping site, leading to retardation of the electrons-holes recombination, while Fe3+ doping has a main effect on hindrance of anatase crystal growth of the composite films. Therefore, 20N/3SnO2/TiO2 composite thin film exhibits greater photocatalytic activity and disinfection efficiency than those of undoped and Fe3+ doped TiO2 films. It was found that the bacterial inactivation of the prepared films correlates closely to photocatalytic activity performed by degradation of methylene blue dye solution. The 20N/3SnO2/TiO2 composite film can kill E. coli 97% within 5 cycled water treatment (~93 min) while Fe3+/3SnO2/TiO2, undoped TiO2 and UV alone can kill only 62, 65 and 58%, respectively. The 20N/3SnO2/TiO2 films coated on glass fibers are expect to be applied as an antibacterial photocatalyst for water purification.

Epitaxy of Porous and Photocatalytically Active TiO2 Films at 50°C

2011 ◽  
Vol 64 (9) ◽  
pp. 1235 ◽  
Author(s):  
Gregory K. L. Goh ◽  
Kelvin Y. S. Chan ◽  
Gao S. Huang ◽  
Qui L. Tay
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Liquid Phase ◽  
Anatase Tio2 ◽  
Blue Dye ◽  
Tio2 Films ◽  
Methylene Blue Dye ◽  
Liquid Phase Deposition ◽  
Grown Film ◽  
Tio2 Thin Films

Epitaxial anatase TiO2 thin films were grown on (001) oriented SrTiO3 single crystal substrates by liquid phase deposition at 50°C. The film consisted of nanosized crystallites and exhibited a significant void fraction of 31 %. This contributed to the cracking of thicker films due to the generation of capillary stresses in the nanosized pores during drying. This porosity also comes in useful during the photodegradation of a methylene blue dye by an as-grown film.

scholarly journals Synthesis and Application of Fe-Doped TiO2-Halloysite Nanotubes Composite and Their Potential Application in Water Treatment

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Emmanuel Nyankson ◽  
Benjamin Agyei-Tuffour ◽  
Jonas Adjasoo ◽  
Annan Ebenezer ◽  
David Dodoo-Arhin ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Water Treatment ◽  
Potential Application ◽  
Naproxen Sodium ◽  
Diffuse Reflectance Spectroscopy ◽  
Halloysite Nanotubes ◽  
Isotherm Models ◽  
Blue Dye ◽  
Electromagnetic Spectrum ◽  
X Ray

In this work, the potential application of TiO2-Fe-HNT photocatalyst-adsorbent composite in water treatment technologies was confirmed. The photocatalyst-adsorbent composite (TiO2-Fe-HNTs) was synthesized by the hydrothermal method and characterized by X-ray diffraction, thermogravimetric analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, and diffuse reflectance spectroscopy. The adsorption and photocatalysis mechanism by the TiO2-Fe-HNT composite were examined on methylene blue dye, rhodamine blue dye, naproxen sodium (pharmaceutical drug waste), and imidacloprid (pesticide). The TiO2-Fe-HNT composite was active in UV and visible regions of the electromagnetic spectrum. The adsorption and photocatalytic efficiency increased with increasing amount of HNTs. The photocatalyst-adsorbent composite exhibited excellent removal efficiency for pharmaceutical waste (naproxen sodium) and pesticides (imidacloprid). An adsorption equilibrium data fitted well with the pseudo-second-order kinetics for both methylene blue and rhodamine blue dyes with the intraparticle model describing its rate-controlling steps. The Langmuir and Freundlich isotherm models further described the adsorption of methylene blue and rhodamine blue molecules, respectively.

scholarly journals Effect of Oxalic Acid Leaching on Photocatalytic Activity of Natural Sphalerite

2020 ◽  
Author(s):  
Chukwunonso Onyenanu ◽  
Lovet Emembolu
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Irradiation Time ◽  
Acid Leaching ◽  
Blue Dye ◽  
Light Illumination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Illumination

Abstract Photocatalytic activity of the natural semiconducting sphalerite mineral from Abuni, Nasarawa State, Nigeria was studied for the degradation of methylene blue (MB). Natural Sphalerite as a visible – light responsive photocatalyst was characterized by X ray diffraction (XRD), X ray fluorescence (XRF) and surface area analysis. To further enhance the photocatalytic activity of natural Sphalerite, the chemical composition of the sphalerite was varied via leaching with oxalic acids. The photocatalytic activity of the Natural sphalerite, leached sphalerite and as well as the calcined leachates was tested for MB degradation under visible light illumination. The result shows a very high percentage of MB degradation by natural sphalerite after 60mintues of light irradiation time. A composite of ZnO -α –Fe2O3 -ϒ-Fe2O3 with traces amount of MoO and MnO2 was synthesized by calcination of the obtained leachates at 1000°C for 4hours. The photocatalytic degradation of methylene blue dye follows pseudo first order kinetics.

scholarly journals Degradation of Methylene Blue Dye in the Presence of Visible Light Using SiO2@α-Fe2O3 Nanocomposites Deposited on SnS2 Flowers

2018 ◽  
Author(s):  
Sridharan Balu ◽  
Kasimayan Uma ◽  
Guan-Ting Pan ◽  
Thomas C.-K. Yang ◽  
Sayee Kannan Ramaraj
Keyword(s):  
Methylene Blue ◽  
Three Dimensional ◽  
Semiconductor Materials ◽  
Blue Dye ◽  
Core Shell ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Scanning Electron

Semiconductor materials have been shown to have better photocatalytic behavior and can be utilized for the photodegradation of organic pollutants. In this work, three-dimensional flower-like SnS2 were synthesized by a facile hydrothermal method. Core-shell structured SiO2@α-Fe2O3 nanocomposites were then deposited on the top of the SnS2 flowers. The as-synthesized nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), Brunauer-Emmett-Teller (BET) and photoluminescence spectroscopy (PL). The photocatalytic behavior of the SnS2-SiO2@α-Fe2O3 nanocomposites was observed by observing the degradation of methylene blue (MB). The results show an effective enhancement of photocatalytic activity for the degradation of MB especially for the 15 wt. % SiO2@α-Fe2O3 nanocomposites on SnS2 flowers.

scholarly journals Valorization of snail shell (Helixaspersa) from Tangier-Tetouan region (north of Morocco): an application to eliminate methylene blue

2019 ◽  
Vol 8 (2) ◽  
pp. 94-102
Author(s):  
Ghizlane Erradi ◽  
Farida El yousfi ◽  
Mostafa Stitou
Keyword(s):  
Methylene Blue ◽  
Positive Impact ◽  
Industrial Effluents ◽  
Blue Dye ◽  
Optimal Conditions ◽  
X Ray Diffraction ◽  
Snail Shell ◽  
X Ray ◽  
Industrial Sectors ◽  
Effective Removal

Removal of industrial waste becomes increasingly critical for environmental protection. This study aims to search for effective and less expensive adsorbents in order to remove methylene blue (MB) commonly used in many industrial sectors. To this end, we experiment Helix aspersa snail shell as a biosorbent for the removal of MB. The raw snail shells were cleaned, smashed, and characterized afterwards using a scanning electron microscopy (SEM) coupled with an energy dispersive X-Ray analysis (EDX) and by X-ray diffraction. Different parameters were tested in order to identify the optimal conditions for the effective removal of MB. Our experimental results showed that, within the first ten minutes, a remarkable elimination of methylene blue dye reaching a percentage of 82%, with the following optimal conditions; 3.5 g of the adsorbent, initial MB concentration of 20 mg/L, the temperature of 15 °C, and agitation of 250 rpm. This study showed that the use of snail shell waste has inevitably a positive impact on the protection of the environment, in particular, the purification of industrial effluents.

Removal of Methylene Blue Dye Using Metal-Free g-C3N4 Photocatalyst over Natural Sunlight Irradiation

2020 ◽  
Vol 975 ◽  
pp. 115-120
Author(s):  
Chaval Sriwong ◽  
Kittisak Choojun
Keyword(s):  
Methylene Blue ◽  
Blue Dye ◽  
Sem Images ◽  
Sunlight Irradiation ◽  
X Ray ◽  
Natural Sunlight ◽  
Metal Free ◽  
Annealing Temperatures ◽  
Light Region ◽  
Bet Specific Surface Area

This work presented the high activity of metal-free g-C3N4 photocatalyst for methylene blue (MB) removing over natural sunlight irradiation. These g-C3N4 photocatalysts materials were synthesized by a conventional thermal condensation method using melamine as a precursor under treated at the various annealing temperatures (450 °C, 500 °C, 550 °C, 600 °C and 650 °C). All as-synthesized samples were characterized and confirmed by a several techniques, such as, X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), UV-vis diffuse reflectance spectrometer (DRS), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), and Brunauer-Emmett-Teller (BET) specific surface area. XRD and FTIR results confirmed that the as-synthesized g-C3N4 samples were completely synthesized at annealing temperature of 500 °C. SEM images showed the morphologies of the g-C3N4 samples had more flake-like structures upon the increasing of annealing temperatures. While DRS results indicated that the absorption edges of as-synthesized g-C3N4 samples were shifted to visible-light region, except the sample as-synthesized at 650 °C (g-C3N4-650 °C). Moreover, the photocatalytic properties of metal-free g-C3N4 photocatalyst materials were evaluated by degrading of MB dye solution under natural sunlight irradiation for 100 min. The results revealed that the highest photocatalytic activity was exhibited by the sample synthesized at 600 °C, which the apparent rate constant (kapp.) was 0.0291 min-1. The orders of activities as: g-C3N4-600 °C > g-C3N4-650 °C > g-C3N4-550 °C > g-C3N4-500 °C > g-C3N4-450 °C. Hence, the metal-free g-C3N4 photocatalyst appears to be an attractive-material for water or wastewater purification applications over activated by sunlight irradiation.

scholarly journals CuFe2O4@CuO: A Magnetic Composite Synthesized by Ultrasound Irradiation and Degradation of Methylene Blue on Its Surface in the Presence of Sunlight

Proceedings ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 17 ◽  
Author(s):  
Ahmad Massoud-Sharifi ◽  
Gheffar K. Kara ◽  
Mahboubeh Rabbani
Keyword(s):  
Methylene Blue ◽  
Environmental Remediation ◽  
Spinel Ferrite ◽  
Sol Gel ◽  
Chemical Properties ◽  
Pollutant Removal ◽  
Magnetic Composite ◽  
Hydrothermal Route ◽  
X Ray ◽  
Practical Applications

Spinel ferrite MFe2O4 (M = Cu, Ca, Mg, Ni, etc.) nanoparticles and their composites are a new promising materialbecause they have shown great interest in the field of sensing, optoelectronics, catalysis, and solar cells due to their unique physical and chemical properties that differ from their bulk structures. Today, lots of CuFe2O4 nanomaterials have been synthesized by different methods, such as hydrothermal route and sol-gel combustion methods. Nevertheless, there are hardly any results about photocatalytic activity. For this reason, we tried to increase optical properties by preparing a composite of CuFe2O4 nanomaterials with other oxides. In this paper, a CuFe2O4@CuO magnetic composite was synthesized via an ultrasound method. The samples prepared were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), diffuse reflectance spectrpscopy (DRS), field emission scanning electron microscopy (FESEM) images, vibrating sample magnetometer (VSM), and elemental analysis (energy-dispersive X-ray (EDX)). The catalytic activity of as-synthesized CuFe2O4@CuO was evaluated using the degradation of methylene blue. Furthermore, a possible reaction mechanism was discussed. Finally, the catalyst was used for effective degradation of methylene blue (MB) in its solution, which indicated a potential for practical applications in water pollutant removal and environmental remediation.

Physicochemical Properties of Oxalic Acid-Modified Chitosan/Neem Leave Composites from Pessu River Crab Shell

2019 ◽  
Vol 17 (9) ◽  
Author(s):  
Oluwadayo Francis Asokogene ◽  
Muhammad Abbas Ahmad Zaini ◽  
Misau Muhammad Idris ◽  
Surajudeen Abdulsalam ◽  
Aliyu El-Nafaty Usman
Keyword(s):  
Methylene Blue ◽  
Oxalic Acid ◽  
Surface Area ◽  
Dye Adsorption ◽  
Textural Properties ◽  
Bet Surface Area ◽  
Blue Dye ◽  
Crab Shell ◽  
Sem Images ◽  
X Ray

Abstract This study was aimed to evaluate the characteristics of chitosan from Pessu river crab shell and its derivatives as prospective adsorbent. The synthesized chitosan (CH) was modified with 10 % (w/v) oxalic acid (CHOx), while the composites (CHOx-ANL1, CHOx-ANL2 and CHOx-ANL3) were designated according to the amount of activated neem leave (ANL). The materials were characterized by Fourier transform infrared (FTIR), energy-dispersive X-ray (EDAX), X-ray diffraction (XRD), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET), thermal gravimetric (TGA) and methylene blue dye adsorption. The FTIR spectra of chitosan samples show the characteristics of primary and secondary amine/amide groups. The SEM images exhibit a tight, porous and fractured surface, which is covered with activated neem leave for the composites. The BET surface area of chitosan materials is in the increasing order of, CH < CHOx-ANL1 < CHOx-ANL2 < CHOx < CHOx-ANL3. CHOx-ANL3 displays a higher surface area of 389 m2/g, and 70.9 % mesoporosity. Despite its lower surface area of 258 m2/g (65.4 % mesoporosity), CHOx-ANL1 exhibits a greater methylene blue adsorption of 90.8 mg/g at dye concentration of 300 mg/L. The possible removal mechanisms include ionic interaction between dye molecules and functional groups, and surface adsorption due to the textural properties of chitosan samples. Chitosan from Pessu river crab shell and its derivatives are promising adsorbent candidate for dyes and heavy metals removal from water.

Decolorization of Methylene Blue by Photocatalyst in the Ag3PO4-AgI System

2014 ◽  
Vol 970 ◽  
pp. 29-32 ◽  
Author(s):  
Pongsaton Amornpitoksuk ◽  
Sumetha Suwanboon
Keyword(s):  
Methylene Blue ◽  
Mixed Phase ◽  
Photocatalytic Properties ◽  
Precipitation Method ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Co Precipitation

The co-effect of PO43- and I- on the formation of a heterosturucture photocatalyst in the Ag3PO4-AgI system was studied by the co-precipitation method between AgNO3 and the precipitating agent. The precipitating agent was prepared by varying the mole ratios between Na2HPO4 and KI. At 10 mol.% KI, the product showed the mixed phase between Ag3PO4 and un-identified phase. For 30 - 90 mol.% KI, the un-identified phase and AgI were detected in the x-ray diffraction patterns. The un-identified phase strongly adsorbed the methylene blue dye. The product prepared from 30 mol.% KI had the highest content of un-identified phase and also showed the highest degree of decolorization in the dark. The photocatalytic properties of products in this system were confirmed by the decolorization of methylene blue under visible illumination.

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