scholarly journals SYNTHESIS OF Fe2O3-MONTMORILLONITE AND ITS APPLICATION AS A PHOTOCATALYST FOR DEGRADATION OF CONGO RED DYE

2010 ◽  
Vol 5 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Karna Wijaya ◽  
Iqmal Tahir ◽  
Nanik Haryanti

The preparation of Fe2O3-montmorillonite and it's application as a catalyst for congo red dye photodegradation has been carried out. Fe2O3-montmorillonite was prepared by mixing the iron complexes pillaring agent and montmorillonite. The product was calcined at 250 oC for 5 hours. Montmorillonite and calcined product was analyzed by X-ray diffractometry (X-RD), infrared spectrophotometry (FTIR), gas  sorption analyser, X-ray fluorescense (X-RF) and UV/Vis diffuse reflectance spektrophotometry (UV-DRS). Fe2O3-montmorilonite then was used as a catalyst on congo red dye photodegrdation by UV-illuminating a mixture of 50 mg Fe2O3-montmorillonite and 25 mL congo red 10­-4M at 365 nm at various illuminating times. Adsorption of congo red on Fe2O3-montmorillonite and montmorillonite was also performed as a comparison. Result of X-RD analysis showed that the 001 reflection of  Fe2O3-montmorillonite was not  detected that probably indicating the formation of house of card stucture and this result was supported also by the analysis result of distribution of pores and SEM photography result. Results of the XRF analysis showed that iron content increased  from 5.21 % (w/w) in montmorillonite to 25.12 % (w/w) in Fe2O3-montmorillonite. UV- DRS analysis showed the increament of band gap energy from 3.69 eV in the iron oxide bulk to 3.8 eV in Fe2O3-montmorillonite. Specific surface area of the montmorillonite also increased significantly from 69,71 m2/g to 126,49 m2/g and total pores volume increased from 50.70x10-3 mL/Å/g  to 107.89x10-3 mL/Å/g, respectively. Photodegradation of congo red using Fe2O3-montmorillonite caused the decreament of congo red concentration up to 90.22 %  on UV illumination for 60 minutes. Adsorption of congo red on Fe2O3-montmorillonite reached 84.4% and on  montmorillonite was 75.15 %.   Keywords: photodegradation, congo red, Fe2O3-montmorillonite, UV light

2021 ◽  
Vol 30 ◽  
pp. 02010
Author(s):  
Irina Ryltsova ◽  
Evgenia Tarasenko ◽  
Olga Lebedeva

Layered double hydroxide containing Ni3+ (Mg/AlNi-LDH) was successfully synthesized by co-precipitation in an oxidizing media. The resulted product was characterized using X-ray diffraction, wavelength dispersive X-ray fluorescence spectrometry. The activity of Mg/AlNi-LDH in the process of photodegradation of Congo red dye using UV light irradiation was evaluated. The initial rate of photodegradation of the dye in the presence of LDH is 1.6 times higher than that of UV irradiated solution. The kinetic data obtained for photodegradation process can be adequately described by pseudo-first-order kinetic model. The presence of Mg/AlNi – LDH leads to increased photodegradation yield compared to destruction only by UV irradiation.


Fibers ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Saadia Lahreche ◽  
Imane Moulefera ◽  
Abdelkader El El Kebir ◽  
Lilia Sabantina ◽  
M’hamed Kaid ◽  
...  

The present work was aimed to evaluate the adsorption properties of activated carbons based on prickly pear seeds (PPS) and conductive polymer matrix based on polyaniline (PANI) for the removal of anionic Congo red (CR) dye from aqueous solutions. The adsorbent was prepared by polymerization of aniline in the presence of activated PPS by phosphoric acid and sodium hydroxide. The samples were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and the Brunauer–Emmett–Teller (BET) methods. The adsorption kinetics were studied using UV-visible (UV/Vis) spectroscopy. The characterization data suggest that the adsorption of the Congo red dye is enhanced because PANI chain molecules, which are especially accountable for removal through π—π interaction and H-bonding with the CR, are adsorbed/tethered onto the acid-activated PPS (PPSH), and thus surmount the mass transfer limitation by being best exposed to the CR-adsorbed molecule. The adsorption kinetics follows the pseudo-second order process. The correlation coefficients (R2) for Langmuir, Freundlich and Tempkin showed that the adsorption values obey Freundlich and Tempkin isotherm models. Moreover, the isotherm was most accurately described by the Freundlich model, and the maximum removal percentage was calculated to be 91.14% under optimized conditions of pH 6.6, 1 g/L of adsorbent dosage, and an initial CR dye concentration of 20 mg·L−1. Importantly, the hybrid adsorbent exhibited the highest adsorption capacity (80.15%) after five cycles of the adsorption–desorption process. Thermodynamic parameters, such as entropy changes, enthalpy changes and Gibbs free energy, were also evaluated. These results indicated that the PANI matrix can generally be better utilized for the removal of Congo red dye when appropriately dispersed on the surface of suitable support materials. These results provide a new direction to promote the separable adsorbents with increasing performance for adsorption of dye impurities from wastewater.


2017 ◽  
Vol 17 ◽  
pp. 166-170 ◽  
Author(s):  
M. Ahila ◽  
D. Pathinettam Padiyan

Bi2O3 nanostructures were synthesized through a simple electrolysis based oxidation using NaOH electrolyte and annealed at 300 °C, 400 °C, 500 °C and 600 °C. The obtained Bi2O3 nanostructures were characterized using X-ray diffraction and photoluminescence spectroscopy (PL). Bi2O3 crystal structure was confirmed by XRD. When free electron and holes are combined together then emission signals are emitted from PL spectra. With this process, it is studied about the recombination and separation of photo generated holes and electrons. The photocatalytic activities of Bi2O3 films were evaluated for the degradation of Congo red in aqueous solution under UV light irradiation. Among the four samples, Bi2O3 films annealed at 300 °C have better efficiency in removing the congo red dye. For Bi-3, the initial concentration of 10 ppm decreases to 1.11 ppm after 420 min.


2021 ◽  
Vol 16 (3) ◽  
pp. 481-490
Author(s):  
Poedji Loekitowati Hariani ◽  
Muhammad Said ◽  
Addy Rachmat ◽  
Fahma Riyanti ◽  
Handayani Citra Pratiwi ◽  
...  

NiFe2O4 nanoparticles had been successfully synthesized by solution combustion method using urea fuel (organic precursor). The synthesized NiFe2O4 were characterized by X-ray diffraction (XRD), Scanning electron microscopy-Electron Dispersive X-ray Spectroscopy (SEM-EDs), Transmission Electron Microscopy (TEM), Fourier Transform Infra-Red (FTIR), Vibrating Sample Magnetometer (VSM), UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS), and Point of Zero Charge (pHpzc). NiFe2O4 nanoparticles irradiated with visible light were employed to degrade Congo red dye with the following variable: solution pH (3–8), H2O2 concentration (0.5–3 mM), and Congo red concentration (100–600 mg/L). XRD analysis results showed that the NiFe2O4 nanoparticles had a cubic spinel structure. The particle sizes are in the range of 10–40 nm. The magnetic properties of NiFe2O4 nanoparticles determined using VSM showed a magnetization saturation value of 47.32 emu/g. UV-Vis DRS analysis indicated that NiFe2O4 nanoparticles had an optical band gap of 1.97 eV. The success of synthesis was also proven by the EDS analysis results, which showed that the synthesized NiFe2O4 nanoparticles composed of Ni, Fe, and O elements. The removal efficiency of Congo red dye was 96.80% at the following optimum conditions: solution pH of 5.0, H2O2 concentration of 2 mM, Congo red dye concentration of 100 mg/L, and contact time of 60 min. The study of the photodegradation kinetics follows a pseudo-first order reaction with a rate constant value of 0.0853 min−1. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 


2019 ◽  
Author(s):  
Pejman Monazzam ◽  
azadeh ebrahimian pirbazari ◽  
Behnam Fakhari Kisomi ◽  
Ziba Khodaee

In this work, we focused on improvement of rutile-type TiO2 degradation efficiency by cobalt doping and decorating on carbon nanotubes walls (CNTs) (Co-TiO2/CNTs). X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM), diffuse reflectance spectroscopy (DRS), and nitrogen physisorption were used to characterize the prepared samples. The XRD results indicated after cobalt doping, we obtained rutile phase as the major phase for cobalt containing samples. The band gap energy of the synthesized samples were calculated by Kubelka-Munk equation using diffuse reflectance spectra. The surface area of the samples was obtained by BET model and average pore diameter and pore volume of the samples were extracted from desorption branch of BJH model. The effectiveness of the samples was examined through degradation of 2,4-dichlorophenol (2,4-DCP) as a model of organic pollutants under visible light. We achieved 27% and 50% visible light degradation of 2,4-DCP in the presence of pure TiO2 and Co-TiO2/CNTs after 180 min irradiation, respectively. The high visible light activity of Co-TiO2/CNTs sample can be approved that the presence of cobalt and CNTs reduce the band gap energy and sensitize TiO2 surface to visible light respectively. The mechanism for degradation of 2,4-DCP by Co-TiO2/CNTs photocatalyst under visible light is proposed.


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 299
Author(s):  
Yousef A. Alsabah ◽  
Mohamad S. AlSalhi ◽  
Eltayeb M. Mustafa ◽  
Abdelrahman A. Elbadawi ◽  
Sandhanasamy Devanesan ◽  
...  

Ba2−xSrxZnWO6 double perovskite (DP) oxide compounds (x = 1, 1.25, 1.5, 1.75, 2) were successfully created by means of conventional solid-state techniques. The crystal structures of our series were studied using an X-ray diffractometer. The x = 1 compound has a cubic (Fm-3m) crystal structure, the 1 ≤ x ≤ 2 compounds have tetragonal (I4/m) symmetry, and the phase was transferred to monoclinic (P21/n) symmetry for the Sr2ZnWO6 (x = 2) compound. Scanning electron microscopy (SEM) was used to investigate the morphology of the series, showing that the samples had crystallized microstructures. Molecular bonds were investigated using Fourier transform infrared and Raman spectroscopies, which confirmed the double perovskite octahedral geometry for the samples in our series. Furthermore, the octahedral W–O6 anti-symmetric stretching mode was found to occur. The optical properties of the Ba2−xSrxZnWO6 series were studied using Ultraviolet–visible (UV–vis) diffuse reflectance and photoluminescence (PL) spectroscopies. The absorption edge of the samples appeared around the near-violet and visible spectra, between 336–360 nm. The band gap energy was investigated in two ways—using the absorption cutoff and Tauc plots—which increased from 3.52 to 3.7 eV with increasing substitution of Ba2+ by Sr2+. Furthermore, excitation and emission spectra were collected at room temperature. A broad band at 260–360 nm appeared in the PLE spectra for all samples, and the PL spectra of the samples had a band that spread from 320–450 nm.


Dyeing industry discharges large amount of colored wastewater into water bodies without proper treatment. There are various methods to treat wastewater, but recently Photocatalytic treatment has been proven effective. So an effective Iron /Titanium Dioxide (Fe/TiO2) photocatalytic composite has been synthesized by sol-gel method. The synthesized Fe /TiO2 composite was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), Energy Dispersive Spectroscopy (EDAX). The photocatalytic degradation study of Fe/TiO2 composite under UV light was studied using the aqueous solution of anionic dye Congo Red. The effect of various parameters such as catalyst loading, pH and initial concentration of the dye on degradation has been investigated. The maximum degradation of Congo Red dye concentration in aqueous medium was obtained at pH=5 and 200 mg/l of Fe/TiO2 composite for 10 mg/l concentration of Congo Red dye. Finally, the results prove that photodegradation of Congo Red dye in aqueous solution using composite was very effective under UV irradiation


2012 ◽  
Vol 503-504 ◽  
pp. 262-265 ◽  
Author(s):  
Zhu Xing Tang ◽  
Yin Chen ◽  
Jun Xue ◽  
Shuang Yue

In this paper, nano-Fe3O4 as sorbent was used to remove Congo red dye from aqueous solution, in order to investigate its adsorption properties. Fe3O4 nano-particles were synthesized by hydrothermal method, and were characterized by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray Powder Diffraction (XRD) to examine their size, morphology and property. The adsorption and removal of Congo red dye from aqueous solution on nano-Fe3O4 was studied in batch equilibrium experiments. These results showed an excellent adsorption capability for Congo red with a maximum adsorption capacity of 1395mg•g-1 at 20°C and pH2.0. It indicates that Fe3O4 nano-particles can be effectively used to remove color from wastewater containing dyes.


2021 ◽  
Vol 926 (1) ◽  
pp. 012050
Author(s):  
Salni ◽  
M Said ◽  
P L Hariani ◽  
I Apriani

Abstract Fe3O4 has been synthesized using the combustion solution method using glycine as fuel. The Fe3O4 was used as a catalyst in the photocatalytic degradation of Congo red dye. The Fe3O4 were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS), UV-Vis spectroscopy, and vibrating sample magnetometry (VSM). The characterization showed that Fe3O4 has an inverse spinel structure with a crystalline size of 35.6 nm. Fe3O4 has an optical band gap of 2.16 eV, and a saturation magnetization of 83.76 emu/g. The study showed that the highest photocatalytic degradation was at 90 min of irradiation time using visible light irradiation, the concentration of Congo red dye of 10 mg/L, and pH solution of 5, with a photocatalytic degradation efficiency of 97.70%. The experiment indicated that the photocatalytic degradation of the Congo red dye by Fe3O4 followed a pseudo-first-order. Fe3O4 is effective as an antibacterial against gram-positive bacteria (Streptococcus aureus) and gram-negative bacteria (Escherichia coli).


TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 157-164 ◽  
Author(s):  
Shengdan Wang ◽  
Wenhua Gao ◽  
Kefu Chen ◽  
Jinsong Zeng ◽  
Jun Xu ◽  
...  

Cellulose nanofibrils (CNF) were prepared by cellulase in conjunction with mechanical disintegration from the bleached softwood kraft pulp and labelled by Congo red dye. The labelled CNF were used to investigate the retention and distribution of CNF in paper handsheets. The retention of the labelled CNF was obtained by measuring the absorbance of white water using an ultraviolet-visible spectrophotometer. The results showed that this method for measuring the retention was rapid, feasible, and sensitive, owing to the high correlation coefficient R2 (0.9993) of the standard curve. The labelled CNF showed even distribution in paper handsheets. The colorimetric values of paper handsheets were explored with a residual ink analyzer.


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