scholarly journals Decomposition of the Methylene Blue Dye Using Layered Manganese Oxide Materials Synthesized by Solid State Reactions

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
M. E. Becerra ◽  
A. M. Suarez ◽  
N. P. Arias ◽  
O. Giraldo
Keyword(s):  
Methylene Blue ◽  
Manganese Oxides ◽  
Catalytic Performance ◽  
Synthesis Temperature ◽  
Thermal Reduction ◽  
Solid State Reactions ◽  
General Mechanism ◽  
Blue Dye ◽  
Ac Conductivities ◽  
X Ray Diffraction

The modulation in the synthesis parameters of layered manganese oxides allowed us to produce materials with different AC conductivities. These conductivities were correlated with the catalytic performance of the materials in the decomposition of methylene blue, as a model of electron transfer reactions. The manganese oxides were prepared by thermal reduction of KMnO4 at 400°C and 800°C where one sample was heated at 1°C/min and the other was heated at 10°C/min. The materials were characterized by atomic absorption, average oxidation states of manganese, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The results indicate that, by increasing the synthesis temperature, both the lamellar arrangement and the crystal size increased, while the Mn4+ amount in the material decreased. Furthermore, it was observed that as the conductivity increases for the materials, the catalytic performance also increases. Therefore, a direct correlation between the conductivity and catalytic performance can be established. For example, the layered manganese oxides material synthesized at 400°C, using a heating rate of 10°C/min, showed the highest AC conductivity and had the best performance in the degradation of methylene blue. Finally, we propose a general mechanism for understanding how manganese oxides behave as catalysts that produce oxidizing species from H2O2 which degrades methylene blue. Our proposed mechanism takes into consideration the state of aggregation of the catalyst, the availability of Mn4+, and the electrical conductivity.

scholarly journals Effect of preparation method in the properties of iron oxide catalysts for fenton reaction

2020 ◽  
Vol 6 (5) ◽  
pp. 0607-0616
Author(s):  
Fabiana Maria Barbosa ◽  
Andre Rosa Martins
Keyword(s):  
Methylene Blue ◽  
Iron Oxide ◽  
Fenton Reaction ◽  
Combustion Method ◽  
Catalytic Performance ◽  
Area Measurement ◽  
Blue Dye ◽  
X Ray Diffraction ◽  
X Ray ◽  
Model Molecule

This work discusses methods of preparing iron oxide for the Fenton reaction, using methylene blue as a model molecule. The solids were prepared by precipitation, complexation, combustion, and decomposition and characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electronic microscopy, energy dispersive X-ray spectroscopy, specific surface area measurement and were evaluated for methylene blue removal. The method influenced the structural and surface properties of the solids, and consequently the catalytic performance of the solids. The solid prepared by precipitation showed the highest area, amorphous phase, and the best performance in the adsorption test. On the other hand, the combustion method favored the formation of hematite and traces of magnetite.  The solid prepared by this method showed higher values of the methylene blue dye oxidation./Este trabalho discute métodos de preparação de óxido de ferro para a reação de Fenton, utilizando o azul de metileno como molécula modelo. Os sólidos foram preparados por precipitação, complexação, combustão e decomposição e caracterizados por espectroscopia de infravermelho por transformada de Fourier, difração de raios-X, microscopia eletrônica de varredura, espectroscopia de energia dispersiva de raios-X, medição de área superficial específica e foram avaliados para remoção de azul de metileno. O método influenciou as propriedades estruturais e superficiais dos sólidos e, consequentemente, o desempenho catalítico dos sólidos. O sólido preparado por precipitação apresentou a maior área, fase amorfa e melhor desempenho no teste de adsorção. Por outro lado, o método de combustão favoreceu a formação de hematita e vestígios de magnetita.  O sólido preparado por este método apresentou valores mais altos de oxidação do azul de metileno.

scholarly journals The Removal of Methylene Blue Dye from Aqueous Solutions Using Activated and Non-Activated Bentonites

2003 ◽  
Vol 21 (5) ◽  
pp. 451-462 ◽  
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Leena Abu-Aitah
Keyword(s):  
Methylene Blue ◽  
Ph Value ◽  
Sodium Dodecyl ◽  
Freundlich Isotherm ◽  
Blue Dye ◽  
Batch Adsorption ◽  
Ionic Surfactant ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Initial Ph

An improvement in the adsorption capacity of naturally available bentonite towards water pollutants such as Methylene Blue dye (MBD) is certainly needed. For this purpose, sodium bentonite was activated by two methods: (1) treatment with sodium dodecyl sulphate (SDS) as an ionic surfactant and (2) thermal treatment in an oven operated at 850°C. Batch adsorption tests were carried out on removing MBD from aqueous solution using the above-mentioned bentonites. It was found that the effectiveness of bentonites towards MBD removal was in the following order: thermal-bentonite > SDS-bentonite > natural bentonite. X-Ray diffraction analysis showed that an increase in the microscopic bentonite platelets on treatment with SDS was the reason behind the higher uptake of MBD. An increase in sorbent concentration or initial pH value of the solutions resulted in a greater removal of MBD from the solution. An increase in temperature led to an increase in MBD uptake by the bentonites studied in this work. The Freundlich isotherm model was employed and found to represent the experimental data well.

scholarly journals Modification of Spent Bleaching Earth with WO3 and the Application for Photocatalytic Degradation of Waste Dyestuff under Solar Light

2020 ◽  
Vol 8 (2) ◽  
pp. 84-89
Author(s):  
Noor Hindryawati ◽  
Aman Sentosa Panggabean ◽  
Dirgarini Julia Nurlianti Subagyono ◽  
Rinda Anisyah Putri ◽  
Prilianda Kusmiaty ◽  
...  
Keyword(s):  
Bleaching Earth ◽  
Catalytic Performance ◽  
Morphological Characterization ◽  
Solar Light ◽  
Blue Dye ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dioctahedral Smectite ◽  
Dioctahedral Mica ◽  
Scanning Electron

Degradation of blue dye waste in Sarong Samarinda production using WO3-bleaching earth (BE) has been conducted. Structural and morphological characterization has conducted using X-ray diffraction (XRD), and Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX). The X-ray diffraction results show the mineral on bleaching earth is rectorite dioctahedral mica layer and dioctahedral smectite with a ratio 2:1. The WO3 pattern is appeared after the calcination. After calcination at 500°C, the WO3 is deposited homogeneously on the BE surface. The catalytic performance of WO3-BE for photodegradation of the blue dye waste under the solar light is 99.85 % within 1 h.

scholarly journals Structural and Electrical Studies for Birnessite-Type Materials Synthesized by Solid-State Reactions

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1156 ◽  
Author(s):  
Nayda P. Arias ◽  
María E. Becerra ◽  
Oscar Giraldo
Keyword(s):  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Nitrogen Adsorption ◽  
Synthesis Temperature ◽  
Thermal Reduction ◽  
Solid State Reactions ◽  
Low Frequencies ◽  
Structural Formulas ◽  
Interlayer Region ◽  
Adsorption Desorption

The focus of this paper is centered on the thermal reduction of KMnO4 at controlled temperatures of 400 and 800 °C. The materials under study were characterized by atomic absorption spectroscopy, thermogravimetric analysis, average oxidation state of manganese, nitrogen adsorption–desorption, and impedance spectroscopy. The structural formulas, found as a result of these analyses, were K 0.29 + ( M n 0.84 4 + M n 0.16 3 + ) O 2.07 · 0.61 H 2 O and K 0.48 + ( M n 0.64 4 + M n 0.36 3 + ) O 2.06 · 0.50 H 2 O . The N2 adsorption–desorption isotherms show the microporous and mesoporous nature of the structure. Structural analysis showed that synthesis temperature affects the crystal size and symmetry, varying their electrical properties. Impedance spectroscopy (IS) was used to measure the electrical properties of these materials. The measurements attained, as a result of IS, show that these materials have both electronic and ionic conductivity. The conductivity values obtained at 10 Hz were 4.1250 × 10−6 and 1.6870 × 10−4 Ω−1cm−1 for Mn4 at 298 and 423 K respectively. For Mn8, the conductivity values at this frequency were 3.7074 × 10−7 (298) and 3.9866 × 10−5 Ω−1cm−1 (423 K). The electrical behavior was associated with electron hopping at high frequencies, and protonic conduction and ionic movement of the K+ species, in the interlayer region at low frequencies.

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 Curd Mediated Facile Synthesis of ZnO/Ag/NiO Heterostructures and Visible Light Assisted Photodegradation of Methylene Blue

2020 ◽  
Vol 32 (12) ◽  
pp. 3203-3208
Author(s):  
J.P. Shubha ◽  
B.S. Prathibha ◽  
N. Jayalakshmi
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Visible Light ◽  
Analytical Techniques ◽  
Zinc Nitrate ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Light Concentration

Green fuel perished curd was used to synthesize ZnO/Ag/NiO ternary heterostructure with zinc nitrate, nickel carbonate and silver nitrate as oxidizers. The obtained nanostructure was characterized by various analytical techniques such as powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (FESEM), transmission electron microscopy (TEM). The particles and flakes composition of ZnO/Ag/NiO nanomaterials was confirmed. Photocatalytic activity of ZnO/Ag/NiO was evaluated with methylene blue dye by source of light, concentration of hydrogen ion, catalyst and dye concentrations. The obtained ZnO/Ag/NiO nanoparticles reveal better catalytic property for the photodegradation of methylene blue dye under visible light.

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.

scholarly journals One Novel Zn(II) Nitro-containing Metal Organic Framework for Dye- Adsorption and Photo Degradation

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Weiqi Li ◽  
Xieao Du ◽  
Haiyan He
Keyword(s):  
Methylene Blue ◽  
Hydrothermal Reaction ◽  
Metal Organic Framework ◽  
Dye Adsorption ◽  
Blue Dye ◽  
X Ray Diffraction ◽  
Photo Degradation ◽  
Nitrobenzoic Acid ◽  
Metal Organic ◽  
Organic Framework

A novel metal-organic framework [Zn0.5(L1)(4,4'-Bpy)0.5], (HU21, HU for Hohai University, L1 = 4-hydroxy-3-nitrobenzoic acid, 4,4'-bipyridine = 4,4'-Bpy), has been isolated through hydrothermal reaction. Single-crystal X-ray diffraction reveals the compound features a 1D fishbone-like chain. A fast adsorption rate of methylene blue with HU21 was observed in the dark, but under irritation the degradation rate of the dye was obviously increased. The degradation of methylene blue dye reached 248 mg/g under light irritation, and the photocatalytic activity reached 96.1%.

Fabrication and characterization of Fe2O3, Bi2O3 and BiFeO3 and evaluation of their photo catalytic performances on degradation of methylene blue dye

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fiza Akram ◽  
Muhammad Saeed ◽  
Javaid Akhtar ◽  
Syed Ali Raza Naqvi ◽  
Atta ul Haq
Keyword(s):  
Methylene Blue ◽  
Free Energy ◽  
Dye Degradation ◽  
Precipitation Method ◽  
Blue Dye ◽  
X Rays ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Blue Solution

Abstract This study reports the fabrication of Fe2O3, Bi2O3, and BiFeO3, characterization and evaluation of the photocatalytic performances for methylene blue dye degradation. The materials were synthesized by precipitation method and characterized by scanning electron microscopy, X-ray diffraction, energy dispersive X-rays analyses, and Fourier transform infrared analyses. The photocatalytic activities of Fe2O3, Bi2O3, and BiFeO3 were compared by performing degradation experiments with 50 mL of 100 mg/L methylene blue solution. The as-prepared BiFeO3 was found as 2.4 times and 1.7 times more effective than Fe2O3 and Bi2O3, with a 79, 47, and 57% catalytic activity, respectively. The degradation of methylene blue over the BiFeO3 catalyst was optimized in terms of pH, catalyst dosage, temperature, and methylene blue concentration. The Eley–Rideal mechanism was proposed to describe the reaction kinetics in terms of the first order and second order kinetics model. Activation energy E (kJ/mol), enthalpy ΔH (kJ/mol), entropy ΔS (J/mol) and free energy ΔG (kJ/mol) were calculated as 20.8, 18.2, 197.5 and −45.3 respectively. The negative value of free energy shows that photodegradation is favored in present conditions.

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