Mo-goethite as new composite for the degradation of methylene blue from the water with H2O2 (original) (raw)
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Adsorption of Methylene Blue onto a Low-Cost And Environmental Friendly Goethite
IOP Conference Series: Earth and Environmental Science, 2019
The commercial adsorbent has been widely used for dye removal, but it is non-economical. The objective of this study is to synthesize a low-cost and environmental friendly goethite as an adsorbent for methylene blue removal from aqueous solution using a batch-adsorption technique. Goethite was synthesized by adding sodium hydroxide to iron salt and aging at 40 °C for 7 and 21 days, then characterized by Infrared spectroscopy (FTIR) and x-ray diffraction (XRD). The results showed that the optimum concentration of adsorbed methylene blue was 300 mg/L with an adsorption capacity of 82.81 and 75.8 mg/g for GPA7 and GT7, respectively. The equilibrium data fit the Langmuir isotherm model with correlation efficient higher than 0,99. Based on cost analysis, GT7 was the cheapest adsorbent, compared to GPA7 and commercial goethite.
Applied Catalysis B: Environmental, 2011
The influence of adding bismuth on the phase composition and morphology of goethite-hematite nanostructures was investigated with the aim to develop an active and stable heterogeneous catalyst for the degradation of an actual pesticide with the photo-Fenton-like process. The iron-based nanostructures were prepared by the hydrothermal treatment of solutions containing both iron and bismuth salts precipitated at high pH by two different methods: co-precipitation and separate precipitation. The tailoring of the aspect ratio of the goethite nanorods is achieved by varying the bismuth content in the preparation method. An increase of the Bi content in the reaction induced the crystallization of hematite nanoplates, while the addition of 20% of bismuth salt gives a monodispersed, homogenous mixture of hematite and BiFeO 3 nanocrystallites.
Applied Catalysis B: Environmental, 2008
Nb-substituted goethites have been prepared and characterized by Mössbauer spectroscopy, XRD, FTIR and BET surface area measurements. The doublet formation in Mössbauer spectra and the decreasing of the crystallinity shown in XRD analyses indicated that the Fe domain size is small, which may be the result of either Fe 3+ substitution for Nb 5+ in the goethite structure or simply the formation of small particle-size goethite when Nb is present. FTIR analyses showed shifts and broadening of the bands as result of the incorporation of Nb 5+ ions into the a-FeOOH structure. The insertion of Nb in the goethite structure caused a significant increase in the BET surface area of the material. The prepared materials were investigated for the H 2 O 2 decomposition and the Fenton reaction in the oxidation of methylene blue dye. It was observed that the introduction of Nb during the synthesis of goethite produced a strong increase in the activity for the dye contaminant oxidation by H 2 O 2 . Theoretical quantum DFT calculations were carried out in order to understand the degradation mechanism for methylene blue with goethites. #
Multi-metal-substituted-goethite as an effective catalyst for azo dye wastewater oxidation
CLEAN - Soil, Air, Water, 2016
Different samples of goethite modified with cobalt, manganese or aluminum were synthesized and characterized by means of X-ray diffraction, chemical analysis, scanning electron microscopy, zeta potential measurements and N 2 adsorption-desorption isotherm analysis. The goethite oxides were tested as efficient catalysts for the degradation of methyl orange (MO, sodium 4-[(4dimethylamino)phenylazo]benzenesulfonate), a sulfonated azo dye indicator, employing potassium persulfate (PS) in water, at pH 3. The Mn, Co and Al substitution in goethite gave rise to active sites for PS activation. The most effective catalyst reached 93 % of degradation at 120 min of reaction. The increase of temperature led to an expected conversion enhancement, and kinetic parameters were calculated for one of the evaluated catalysts. MO degradation curves best fitted to pseudo-second order kinetics. The extent of mineralization, measured as total removed organic carbon (TOC), was also monitored. A significant degree of mineralization was achieved and confirmed by TOC analysis. A mechanism for MO oxidation with SO 4 •− radicals was discarded and a pathway involving peroxymonosulfate species was proposed. The results indicate that the goethite-substituted oxides are effective catalysts for the studied azo dye degradation in aqueous solution.
International Conference on Computer, Communication, Chemical, Materials & Electronic Engineering, (IC4ME2), 2017
In this work, photocatalytic activity of graphene oxide (GO), graphene oxide (GO) along with hydrogen peroxide (H2O2) were tested by photodegrading Methylene Blue (MB) in aqueous solution. The resulted GO nanoparticles were characterized by X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDX). The XRD data confirms the sharp peak centered at 210.44 corresponding to (002) reflection of GO. Based on our results, it was found that the resulted GO nanoparticles along with H2O2 achieved ~92% photodecolorization of MB compared to ~63% for H2O2 under natural sunlight irradiation at pH~7 in 60 min. The kinetics was also studied for photodegradation using both GO and GO with H2O2. Keywords— Graphene Oxide, Hydrogen Peroxide, Methylene Blue, dye, photodecolorization, sunlight.
Rapid Adsorption of Methylene Blue from Aqueous Solutions by Goethite Nanoadsorbents
Environmental Engineering Science, 2012
Iron-oxide nanoadsorbents are attractive for wastewater treatment for two important reasons. First, nanoadsorbents can remove contaminants from wastewater rapidly. Second, iron oxide nanoadsorbents can be employed as catalysts for the decomposition of contaminants and thus eliminate sludge formation. This article investigates the use of iron-oxide nanoadsorbents to remove contaminants from wastewater. A later paper considers their use as catalysts for decomposition. In this study, goethite (a type of iron oxide) nanoparticles was employed for the removal of methylene blue from an aqueous solution, using a batch-adsorption technique. Effects of contact time, initial concentration of methylene blue, temperature, and solution pH on the adsorbed amount of methylene blue were investigated. Adsorption was rapid, as equilibrium was achieved within 20 minutes. An external mass transfer model fit adsorption kinetic results well and provided reasonable overall volumetric mass transfer coefficients. Increases in initial concentration, temperature, and pH favored the adsorption of methylene blue. Adsorption data fit both the Langmuir and Freundlich isotherm models well, with the better fit to the Langmuir model. Thermodynamic studies confirmed that the adsorption reaction was spontaneous and endothermic in nature.
2018
Graphene, a two-dimensional (2D) promising emergent photocatalyst consisting of earth-abundant elements. This study evaluated the potential of graphene oxide (GO) towards photocatalytic degradation of a novel organic dye, Methylene Blue (MB). In this work, photocatalytic activity of graphene oxide (GO), graphene oxide (GO) along with hydrogen peroxide (H2O2) were tested by photodegrading Methylene Blue (MB) in aqueous solution. The resulted GO nanoparticles were characterized by X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDX) and Fourier Transform Infrared Ray Spectroscopy (FTIR). The XRD data confirms the sharp peak centered at 210.44 corresponding to (002) reflection of GO. Based on our results, it was found that the resulted GO nanoparticles along with H2O2 achieved ~92% photodecolorization of MB compared to ~63% for H2O2 under natural sunlight irradiation at pH~7 in 60 min. The influences of oxygen and hydrogen peroxide (H2O2) on the degradation of MB during sunlight/GO process were investigated. Experimental results indicated that oxygen was a determining parameter for promoting the photocatalytic degradation. The rate constant of degradation (k1) increased from 0.019 to 0.042 min −1 for dissolved oxygen content (DOC) 3.5 mgL −1 when direct photocatalysis (MB/GO) and H2O2-assisted photocatalysis (MB/H2O2/GO) were used. Owing to the fact that H2O2 acted as an electron and hydroxyl radicals (•OH) scavenger, the addition of H2O2 should in a proper dosage to enhance the degradation of MB. Moreover, as the initial concentration of dissolved oxygen (DO) was increased from 2.8 to 3.9 mgL −1 , the rate constant of degradation (k1) increased from 0.035 to 0.062 min −1. The mechanism of photodegradation and kinetics were also studied for both direct photocatalysis and H2O2-assisted photocatalysis.
Enhanced Photocatalytic Activity of Cu2O/ZnO/GO Nanocomposites on the Methylene Blue Degradation
Baghdad Science Journal
This study synthesized nanocomposite photocatalyst materials from a mixture of Cu2O nanoparticles, ZnO nanoparticles, and graphene oxide (GO) through coprecipitation and hydrothermal methods. This study aims to determine the optimum composition of Cu2O/ZnO/GO nanocomposites in degrading methylene blue. The nanocomposite was synthesized in two steps: 1 the synthesis of Cu2O and ZnO nanoparticles through the coprecipitation method and the preparation of GO through the modified Hummer method. 2 The preparation of Cu2O and ZnO nanoparticles mixtures with GO through the hydrothermal method to form Cu2O/ZnO/GO nanocomposites. The adsorption-photocatalysis process of methylene blue was done with UV light from a halogen lamp. The characterization results indicated that the optimum composition was Cu2O/ZnO nanocomposite with a ratio of 1:2 and 10% of GO, which had a specific surface area of 35.874 m2 g-1, a pore radius of 19.073 nm, and a pore volume of 0.092 cm3 g-1, and a diameter crys...
Bismuth doped ZnO/MoO2 composites for the catalytic degradation of methylene blue
2021
From past years, the demand of clean water has been increased due to shortage of portable fresh water. Parallel, the use of composite materials for the catalytic degradation of pollutants particularly dyes in industrial effluents has attracted good attention. In this work, bismuth doped ZnO/MoO2 composites were synthesized by co-precipitation method using bismuth chloride, zinc sulphate and sodium molybdate as starting precursors. The structural/morphological studies of these composites were accomplished by UV-Visible spectroscopy, Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy. The catalytic activity of the bismuth doped ZnO/MoO2 composites was investigated by degradation of methylene blue (MB) dye. The degradation of MB was observed to be 75% at only 45 sec and enhanced catalytic activity was observed by increasing Bi content in synthesized composites.
Elsevier, 2021
Hausmannite manganese oxide/reduced graphene oxide (Mn3O4-rGO) nanocomposite (NC) was synthesized by the solvothermal method. The NC was assessed for structural, morphological, and optical properties by XRD, SEM, FE-SEM, Raman, UV–visible, and PL techniques. The XRD pattern exhibits a tetragonal structure of Mn3O4 with an average grain size of ~25.81 nm. Crystalline plane (0 0 2) confirms the successful formation of Mn3O4-rGO NC. Surface morphological images show the crumbled-like structure of graphene sheets on which Mn3O4 nanoparticles (NPs) are randomly distributed. The optical absorption and transmittance properties of NC were studied and the band-gap value was calculated. The photocatalytic activity studies on the degradation of methylene blue (MB) dye under sunlight demonstrated that Mn3O4-rGO NC has high degradation efficiency compared to the pristine materials Mn3O4 and rGO.