In this study, a novel core-shell Fe3O4@MIL-101 (MIL stands for Materials of Institute Lavoisier) composite was successfully synthesized by hydrothermal method and was fully characterized by X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectra, and X-ray photoelectron spectroscopy. The composite was introduced as a catalyst to generate powerful radicals from persulfate for the removal of Acid Orange 7 in an aqueous solution. Effects of the central metal ions of MIL-101, amino group content of MIL-101, and pH were evaluated in batch experiments. It was found that both hydroxyl and sulfate radicals were generated; importantly, sulfate radicals were speculated to serve as the dominant active species in the catalytic oxidation of Acid Orange 7. In addition, a possible mechanism was proposed. This study provides new physical insights for the rational design of advanced metal-organic frameworks (MOF)-based catalysts for improved environmental remediation.
In this study, we have developed a novel and simple method to prepare Fe/FeS core‐shell nanoparticles using thioacetamide. The Fe/FeS nanoparticles were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) in conjunction with EDX analysis. The performance of Fe/FeS nanoparticles was evaluated as catalyst to activate molecular oxygen for Rhodamine B (RhB) removal in aqueous solution. The Fe/FeS nanoparticles shows a much higher reactivity on the activation of molecular oxygen than the pure Fe nanoparticles. A complete set of control experiments were conducted to optimize the reaction conditions, including the dosage of Fe/FeS nanoparticles, the RhB concentration, as well as the initial pH value. Moreover, the free radical quenching studies indicated the generation of the reactive oxygen species, namely hydroxyl radicals (•OH) and superoxide radical anions ( O2•−), and •OH is the predominant one in Fe/FeS‐activated molecular oxygen system. The study reveals that Fe/FeS nanoparticles are a promising candidate for the efficient removal of pollutants. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1673–1678, 2016
Degradation of azo dye Acid Orange 7 (AO7) by zero-valent aluminum (ZVAl) in combination with ultrasonic irradiation was investigated. The preliminary studies of optimal degradation methodology were conducted with sole ultrasonic, sole ZVAl/air system, ultrasonication + ZVAl/air system (US-ZVAl). In ZVAl/air system, the degradation of AO7 could almost not be observed within 30 min. The degradation of AO7 by ZVAl/air system was obviously enhanced under ultrasound irradiation, and the enhancement is mainly attributed to that the production of hydroxyl radicals in ultrasound-ZVAl process was much higher than that in sole ultrasonic or in sole ZVAl/air system. The variables considered for the effect of degradation were the power of ultrasound, the initial concentration of AO7, as well as the initial pH value and the dosage of zero-valent aluminum. The results showed that the decolorization rate increased with the increase of power density and the dosage of ZVAl, but decreased with the increase of initial pH value and initial concentration of AO7. More than 96% of AO7 removal was achieved within 30 min under optimum operational conditions (AO7: 20 mg/L, ZVAl: 2 g/L, pH: 2.5, ultrasound: 20 kHz, 300 W). This study demonstrates that ultrasound-ZVAl process can effectively decolorize the azo dye AO7 in wastewater.
Increasing attention has been paid to pyrite due to its ability to generate hydroxyl radicals in air-saturated solutions. In this study, the mineral pyrite was studied as a catalyst to activate molecular oxygen to degrade Acid Orange 7 (AO7) in aqueous solution. A complete set of control experiments were conducted to optimize the reaction conditions, including the dosage of pyrite, the AO7 concentration, as well as the initial pH value. The role of reactive oxygen species (ROS) generated by pyrite in the process was elucidated by free radical quenching reactions. Furthermore, the concentrations of Fe(II) and total Fe formed were also measured. The mechanism for the production of ROS in the pyrite/H2O/O2 system was that H2O2 was formed by hydrogen ion and superoxide anion (O2(·-)) which was produced by the reaction of pyrite activating O2 and then reacted with Fe(II) dissolved from pyrite to produce (·)OH through Fenton reaction. The findings suggest that pyrite/H2O/O2 system is potentially practical in pollution treatment. Moreover, the results provide a new insight into the understanding of the mechanism for degradation of organic pollutants by pyrite.
In this study, a novel composite containing an iron based metal-organic framework (MOF) and BiOBr was successfully synthesized by a simple method, and was fully characterized by X-ray diffraction patterns, Fourier transform infrared spectra, UV-vis diffuse reflectance spectra, and transmission electron microscopy. Moreover, the photocatalytic activities of BiOBr/MIL-88B(Fe) composites and the pure materials were evaluated by measuring the degradation of Rhodamine B under visible light. The results show that the composite exhibits better photocatalytic activities than pure materials, which can be ascribed to the high adsorption capacity of MIL-88B(Fe) and the enhanced separation of photogenerated charge carriers from assembly of MIL-88B(Fe) on BiOBr. And the effects of various operating parameters such as catalyst dosage, medium pH, the mass ratio of BiOBr, and MIL-88B(Fe) and the dye initial concentration on the degradation of RhB have been studied.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.