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.
Sajjad Lotfi; Bagher Aslibeiki; Mahmoud Zarei
Abstract
Tri-ethylene glycol (TEG) coated Fe3O4 nanoparticles ferrofluid were used for Pb (II) removal from simulated wastewater. The samples were synthesized using a modified co-precipitation method. The prepared samples were characterized by different techniques including X-ray diffraction, Rietveld method, ...
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Tri-ethylene glycol (TEG) coated Fe3O4 nanoparticles ferrofluid were used for Pb (II) removal from simulated wastewater. The samples were synthesized using a modified co-precipitation method. The prepared samples were characterized by different techniques including X-ray diffraction, Rietveld method, FTIR, FESEM, TEM, VSM, TGA, BET and atomic adsorption experiments. The crystallinity of nanoparticles with a cubic spinel ferrite structure and absence of impurity phases were verified using X-ray diffraction and Rietveld method. The presence of TEG was approved by FTIR and thermogravimetric analysis. The VSM results showed that the bonding between the TEG molecules and ferrite nanoparticles, reduces the surface spin disorder, influences the morphology and magnetization, and consequently increases the Pb (II) removal efficiency to a high value of 97%. The obtained high value of adsorption capacity of q=363.4 mg.g-1 with R= 91 % and q=129.4 mg.g-1 with R=97 %shows effective role of TEG coating on Pb (II) adsorption. The interesting results of this study imply that the TEG coated ferrofluid sample is suitable candidate for practical applications.