Siavash Fathi; Bagher Aslibeiki; Reza Torkamani
Abstract
In the recent decades, increasing of pollutant in water resources endanger the human life and other living things. Researchers have applied different methods to eliminate the water contaminants. Photocatalytic is one of these methods that have been used widely for wastewater treatment. In this study, ...
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In the recent decades, increasing of pollutant in water resources endanger the human life and other living things. Researchers have applied different methods to eliminate the water contaminants. Photocatalytic is one of these methods that have been used widely for wastewater treatment. In this study, a series of Mn, Fe, Co, Ni, and Cu doped ZnO nanorods were applied as visible-light-activated catalysts for oxytetracycline (OTC) degradation. Characterization of the nanorods was performed using XRD, FE-SEM, UV-Vis, and PL techniques. The results show that photocatalytic activity of the samples highly depends on morphology, size and band gap energy. The UV–Vis spectroscopy indicate that Fe doping has reduced the band gap energy to 2.91 eV. The variation of band gap permits absorption of low energy photons and excitation of valence band electrons. The photoluminescence spectra reveal that doping has an effective role in inhibiting the recombination of electron/hole pairs during photocatalytic process. The Mn-doped sample exhibits significantly increased photocatalytic activity and greater degradation rate constant (k) in comparison with the pure ZnO.
Ashok V Borhade; Yogita R Shelke; Vivek D Bobade; Dipak R. Tope; Jyoti A. Agashe
Abstract
Water pollution is one of the serious main global concerns that affect humans and numerous people die due to various diseases caused by contaminated water because of the toxic and carcinogenic nature of dyes in effluents. It is essential to develop an efficient and effective method for wastewater ...
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Water pollution is one of the serious main global concerns that affect humans and numerous people die due to various diseases caused by contaminated water because of the toxic and carcinogenic nature of dyes in effluents. It is essential to develop an efficient and effective method for wastewater treatment using a highly active and reusable catalyst. Herein we report heterogeneous catalyst MgZrO3@Fe2O3@ZnO nanoparticles by sol-gel approach. They were characterized by UV-visible diffused reflectance spectroscopy (UV-DRS), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive x-ray analysis (EDAX), and High-resolution transmission electron microscopy (HRTEM) and selected area diffraction. This characterization confirmed the structure of MgZrO3@Fe2O3@ZnO and also confirmed excellent photocatalytic activity for the decolorization of Nigrosin dye under ambient conditions. The 96±0.5 % degradation was observed within 60 min using 20 ppm Nigrosin dye solution with 0.2 g of MgZrO3@Fe2O3@ZnO core-shell nanoparticles. A mechanistic approach for photodegradation of dye was established by Liquid chromatography-mass spectrometry (LCMS) with the identification of numerous smaller fragment molecule
Ashok V. Borhade; Dipak R. Tope; Jyoti A. Agashe; Sachin S. Kushare
Abstract
In the present work, the sol-gel derived powders of the chemical form FeCr2O4@ZnO@MgO Core-shell, has been synthesized and used as a photocatalyst. The synthesized core-shell nanoparticles characterized by various analytical techniques including FTIR, XRD, SEM-EDAX, and HR-TEM-SEAD. The successful performance ...
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In the present work, the sol-gel derived powders of the chemical form FeCr2O4@ZnO@MgO Core-shell, has been synthesized and used as a photocatalyst. The synthesized core-shell nanoparticles characterized by various analytical techniques including FTIR, XRD, SEM-EDAX, and HR-TEM-SEAD. The successful performance of synthesized core-shell photocatalyst FeCr2O4@ZnO@MgO has been also demonstrated for the complete mineralization of Orange G dye. The effect of various operational parameters used in dye degradation such as concentration of dye, light intensity, amount of photocatalyst, effect of light and effect of electrolyte has been studied on the rate of reaction. TEM analysis clearly shows two layers of ZnO and MgO on FeCr2O4. The highest degradation rate was found with concentration of Orange G dye 10 ppm, 0.8 g of FeCr2O4@ZnO@MgO and time 50 min. The recyclability of the photocatalyst, FeCr2O4@ZnO@MgO was performed up to four runs. The degradation mechanism has been established by using LC-MS analysis and it was used to track the numerous intermediate products formed during the course of Orange G dye degradation.
Pantea Arjmandi; Fariba Hargalani
Abstract
A simple and eco-friendly method for synthesis nanoparticles is using a green chemistry technique. Also, the utilization of green nanoparticles for the treatment of industrial wastewater could be an outstanding plan to confront environmental pollutions. The novelty of this study was to use leaf extract ...
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A simple and eco-friendly method for synthesis nanoparticles is using a green chemistry technique. Also, the utilization of green nanoparticles for the treatment of industrial wastewater could be an outstanding plan to confront environmental pollutions. The novelty of this study was to use leaf extract of Stevia Rebaudiana Bertoni for green synthesized TiO₂ NPs and assessing its functioning for the photocatalytic treatment of Naphthol from real sample wastewater in a self-designed photoreactor. The amount of nano-adsorbent changes was studied under different conditions such as the amount of naphthol concentration, pH, and time period of degradation. Results: The results of the XRD showed that the Anatase and Rutile phase of TiO₂ conformed to cards no.JCPDS21-1272 and no.JCPDS21-1276 respectively. The EDX analysis illustrated the existence of TiO₂ with a weight percentage of 50.17 wt.% for Ti and 49/83 for O. The size of the particles in the SEM photo was found to be about 17nm. The removal of naphthol content was measured by the UV-Vis method. The optimum pH for naphthol removal by TiO₂ is pH = 9, the optimal contact time is 20 min, and the optimal concentration of Naphthol is 3 mg/L. Comparing the Freundlich and Langmuir adsorption isotherm models revealed that the absorption model in this study is in complete conformity with the Freundlich adsorption model. This study affirms that the green synthesis of Stevia leaf extracted is a modern beneficial procedure for the preparation of TiO₂ nanoparticles. This method is straightforward, cost-effective, eco-friendly, and rapid.
Kalpesh Isai; Vinod Shrivastava
Abstract
ZnO and 2%Fe-ZnO nanomaterials were prepared by using a low-cost sol-gel method. The synthesized nanomaterials were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). The XRD and SEM studies reveal that the synthesized nanomaterials ...
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ZnO and 2%Fe-ZnO nanomaterials were prepared by using a low-cost sol-gel method. The synthesized nanomaterials were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). The XRD and SEM studies reveal that the synthesized nanomaterials have a hexagonal wurtzite structure with average crystalline size ~ 22-23 nm. EDX analysis confirmed the composition and purity of synthesized nanomaterial. The photocatalytic activity of synthesized nanomaterials was monitored using the spectrophotometric method. Also, the photocatalytic removal of methylene blue (MB) dye from its aqueous solution by using ZnO and 2%Fe-ZnO nanopowder under UV light irradiation was studied. The effect of various parameters such as pH of dye solution, dye concentration, contact time and catalyst dose were investigated. Results of the current study demonstrated that, the maximum degradation using ZnO was 86 % and that for 2%Fe-ZnO was 92 % (under the optimum condition initial dye concentration=10 mg/L and pH =2). This study showed that 2%Fe-ZnO is a promising and better photocatalysts than ZnO.
Janan Parhizkar; Mohammad Hossein Habibi
Abstract
Photocatalytic treatment of wastewater from azo dyes with semiconductors promises efficient method to refine water. Cobalt ferrite is synthesized and utilized for dye removal as a semiconducting composite. To compare photocatalytic performance of its individual oxides, cobalt oxide and iron oxide were ...
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Photocatalytic treatment of wastewater from azo dyes with semiconductors promises efficient method to refine water. Cobalt ferrite is synthesized and utilized for dye removal as a semiconducting composite. To compare photocatalytic performance of its individual oxides, cobalt oxide and iron oxide were synthesized by the same route and applied to water treatment. In this work, cobalt ferrite, cobalt oxide and iron oxide nanoparticles were synthesized as photocatalysts by employing wet chemical method with chloride precursors respectively (CoCl2.6H2O & FeCl3.6H2O, CoCl2.6H2O, FeCl3. 6H2O). The synthesized photocatalysts were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS) and field emission scanning electron microscopy (FESEM). The obtained photocatalysts were coated on glass by Dr Blade method. The degradation of Acid Black 1 (AB1) and Reactive Red 4 (RR4) by cobalt ferrite, cobalt oxide and iron oxide was carried out under UV light irradiation to investigate their photocatalytic activities. FeO nanoparticles were found as the best photocatalyst to achieve maximum degradation of Azo dyes. The high degradation performance of FeO can be attributed to photo-Fenton phenomena-like furthermore photocatalytic process. The Degradation rate of AB1 by photocatalysts decreases in the order of FeO > Co3O4> CoFe2O4. The photocatalytic degradation kinetics of AB1 using photocatalyst nanoparticles was found to be the first order kinetic rate. For RR4, CoFe2O4 followed first order, FeO and Co3O4 followed second order kinetic rate. Presence of iron oxide in cobalt ferrite improved the photocatalytic performance.
Asadollah Mohammadi; Seyed Hossein Mousavi
Abstract
In this work, an efficient photocatalyst based on β-cyclodextrin-glycine-modified TiO2 nanoparticles (TiO2-Gly-βCD NPs) was successfully synthesized. The photocatalytic activity of the prepared TiO2-Gly-βCD was tested on the degradation of methylene blue (MB) and methyl orange ...
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In this work, an efficient photocatalyst based on β-cyclodextrin-glycine-modified TiO2 nanoparticles (TiO2-Gly-βCD NPs) was successfully synthesized. The photocatalytic activity of the prepared TiO2-Gly-βCD was tested on the degradation of methylene blue (MB) and methyl orange (MO) dyes. The enhanced surface properties of TiO2-Gly-βCD photocatalyst generated excellent photocatalytic performance for the photocatalytic degradation of dyes in aqueous solution. These were strongly attributed to the presence of the functional hydroxyl groups and the inner cores of the hydrophobic cavity in β-CD to form inclusion complexes with organic molecules. As compared to the pure TiO2 and TiO2 modified by Gly, the dye degradation rate under UV irradiation was considerably enhanced by TiO2/Gly/βCD as a photocatalyst. In addition, the sonocatalytic degradation of dyes was investigated, and it was found that the ultrasonic waves slightly enhanced the degradation time of dyes. The results indicated that the first-order kinetic model well describes the degradation of MB and MO dyes by TiO2-Gly-βCD. Furthermore, the chemical oxygen demand (COD) values were determined for real industrial wastewater and treated wastewater.
Elsayed Talat Helmy; Ahmed El Nemr; Mahmoud Mousa; Esam Arafa; Shady Eldafrawy
Abstract
This paper describes the photocatalytic degradation of Reactive Blue 19 (RB-19) and Reactive Red 76 (RR-76) dyes pollutant in the industrial wastewater using TiO2, C-doped TiO2(C-TiO2), S-doped TiO2 (S-TiO2) and C,S co-doped TiO2 (C,S-TiO2)nanoparticles as photocatalysts, which were synthesized via sol-gel ...
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This paper describes the photocatalytic degradation of Reactive Blue 19 (RB-19) and Reactive Red 76 (RR-76) dyes pollutant in the industrial wastewater using TiO2, C-doped TiO2(C-TiO2), S-doped TiO2 (S-TiO2) and C,S co-doped TiO2 (C,S-TiO2)nanoparticles as photocatalysts, which were synthesized via sol-gel process. The prepared photocatalysts were characterized by scanning electron microscopy (SEM), X-Ray diffraction (XRD), Fourier transformer infra-red spectroscopy (FTIR), Energy dispersive spectroscopy (EDAX) and ultraviolet-visible absorption spectroscopy (UV-Vis). The dyes degradation was investigated under several experimental parameters such as pH, catalyst load, dye concentration, shaking speed, irradiation time and catalyst recovery. The photocatalytic dose was found to be 1.6 g/L and the efficiency of RB-19 and RR-76 photocatalytic degradation attained 100 % after 1 h irradiation time under visible light. The chemical oxygen demand (COD) values were determined for wastewater and treated wastewater. Toxicity and biological activity of the treated and untreated wastewater on marine aquatic organisms rotifer, artemia and Vibrio parahaemolyticus were investigated.
Asadollah Mohammadi; Ali Aliakbarzadeh Karimi
Abstract
This study describes the adsorption and photocatalytic removal of methylene blue (MB) from aqueous solution by surface-modified TiO2 nanoparticles under ultraviolet irradiation in a batch system. The 5-sulfosalicylic acid grafted TiO2 (5-SA-TiO2) as a photocatalyst was characterized by means of ...
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This study describes the adsorption and photocatalytic removal of methylene blue (MB) from aqueous solution by surface-modified TiO2 nanoparticles under ultraviolet irradiation in a batch system. The 5-sulfosalicylic acid grafted TiO2 (5-SA-TiO2) as a photocatalyst was characterized by means of XRD, FTIR and SEM techniques. The surface of TiO2 nanoparticles was modified by 5-sulfosalicylic acid (5-SA) to increase performance by altering surface properties. Notably, in contrast with the adsorption process, the remarkable removal enhancement of MB dye was observed by photocatalytic degradation process from aqueous solution. The adsorption and photocatalytic degradation kinetics of MB using 5-SA-TiO2 nanoparticles have also been investigated. The results show that the photocatalytic degradation was good fit with the pseudo-first-order kinetic model (R2 > 0.99). The adsorption isotherm of MB onto modified TiO2 nanoparticles fitted into the Temkin equation. In addition, thermodynamic studies indicate the spontaneous behavior of adsorption and photocatalytic degradation processes.