Abstract:Interest in using various nanoparticle catalysts to activate H2O2 with light for organic contaminant and wastewater treatment is steadily increasing. We successfully synthesized magnetically recoverable Cu0.5Mn0.5Fe2O4 nanoparticles using a simple co-precipitation method followed by melamine-assisted calcination. Material characterization revealed that melamine acted as a coordinating agent during the calcination process that promoted a ferrite structure. Copper (Cu)-substitution effectively decreased material… Show more
“… 26 Both XRD and FTIR results confirmed our successfully synthesized catalyst using coprecipitation followed by the melamine-assisted calcination method. Angkaew et al 27 reported that g-C 3 N 4 served as a coordinating agent by forming a metal–melamine complex and/or conjugating with a metal oxide. Under the calcining temperature (550 °C), this complex can further decompose into a spinel ferrite structure and volatile gases (i.e., CO X , NO X , and NH 3 ), successfully preventing α-Fe 2 O 3 formation.…”
Section: Resultsmentioning
confidence: 99%
“…If it was there, it might have been a rapid reaction, and the Fe 3+ was insufficient to react with a large amount of O 2 •– , thereby O 2 formation was only minimal. Moreover, Angkaew et al 27 showed that the ferrites also have photocatalytic performance and were able to produce • OH under light irradiation [ eq 8 ]. Because of the O 2 •– abundance, we ruled out that, once released, the • OH would simultaneously react and provide more 1 O 2 into the system, concordant with our scavenging experiment that rooted for 1 O 2 production.…”
Section: Resultsmentioning
confidence: 99%
“…By this synthesis method, the calcination of coprecipitate particles without the addition of melamine results in the formation of hematite (α-Fe 2 O 3 ) impurity, which significantly decreases the magnetic saturation value (M s ), resulting in poor recoverability of the prepared catalyst. 24,27 This was also confirmed by the FTIR spectra that showed huge adsorption peaks in 400−700 cm −1 region, which can be attributed to the metal−oxygen bonds (Fe−O, Mn−O) occupied at the tetrahedral and octahedral sites of the spinel structure. 26 Both XRD and FTIR results confirmed our successfully synthesized catalyst using coprecipitation followed by the melamine-assisted calcination method.…”
Section: Influential Effectsmentioning
confidence: 99%
“…, thereby O 2 formation was only minimal. Moreover, Angkaew et al 27 showed that the ferrites also have photocatalytic performance and were able to produce • OH under light irradiation [eq 8].…”
Single activation of peroxymonosulfate (PMS) in a homogeneous system is sometimes insufficient for producing reactive oxygen species (ROS) for water treatment applications. In this work, manganese spinel ferrite and graphitic carbon nitride (MnFe 2 O 4 /g-C 3 N 4 ; MnF) were successfully used as an activator for PMS under visible light irradiation to remove the four-mostdetected-hormone-contaminated water under different environmental conditions. The incorporation of g-C 3 N 4 in the nanocomposites led to material enhancements, including increased crystallinity, reduced particle agglomeration, amplified magnetism, improved recyclability, and increased active surface area, thereby facilitating the PMS activation and electron transfer processes. The dominant active radical species included singlet oxygen ( 1 O 2 ) and superoxide anions (O 2•− ), which were more susceptible to the estrogen molecular structure than testosterone due to the higher electron-rich moieties. The self-scavenging effect occurred at high PMS concentrations, whereas elevated constituent ion concentrations can be both inhibitors and promoters due to the generation of secondary radicals. The MnF/PMS/vis system degradation byproducts and possible pathways of 17β-estradiol and 17α-methyltestosterone were identified. The impact of hormone-treated water on Oryza sativa L. seed germination, shoot length, and root length was found to be lower than that of untreated water. However, the viability of both ELT3 and Sertoli TM4 cells was affected only at higher water compositions. Our results confirmed that MnF and visible light could be potential PMS activators due to their superior degradation performance and ability to produce safer treated water.
“… 26 Both XRD and FTIR results confirmed our successfully synthesized catalyst using coprecipitation followed by the melamine-assisted calcination method. Angkaew et al 27 reported that g-C 3 N 4 served as a coordinating agent by forming a metal–melamine complex and/or conjugating with a metal oxide. Under the calcining temperature (550 °C), this complex can further decompose into a spinel ferrite structure and volatile gases (i.e., CO X , NO X , and NH 3 ), successfully preventing α-Fe 2 O 3 formation.…”
Section: Resultsmentioning
confidence: 99%
“…If it was there, it might have been a rapid reaction, and the Fe 3+ was insufficient to react with a large amount of O 2 •– , thereby O 2 formation was only minimal. Moreover, Angkaew et al 27 showed that the ferrites also have photocatalytic performance and were able to produce • OH under light irradiation [ eq 8 ]. Because of the O 2 •– abundance, we ruled out that, once released, the • OH would simultaneously react and provide more 1 O 2 into the system, concordant with our scavenging experiment that rooted for 1 O 2 production.…”
Section: Resultsmentioning
confidence: 99%
“…By this synthesis method, the calcination of coprecipitate particles without the addition of melamine results in the formation of hematite (α-Fe 2 O 3 ) impurity, which significantly decreases the magnetic saturation value (M s ), resulting in poor recoverability of the prepared catalyst. 24,27 This was also confirmed by the FTIR spectra that showed huge adsorption peaks in 400−700 cm −1 region, which can be attributed to the metal−oxygen bonds (Fe−O, Mn−O) occupied at the tetrahedral and octahedral sites of the spinel structure. 26 Both XRD and FTIR results confirmed our successfully synthesized catalyst using coprecipitation followed by the melamine-assisted calcination method.…”
Section: Influential Effectsmentioning
confidence: 99%
“…, thereby O 2 formation was only minimal. Moreover, Angkaew et al 27 showed that the ferrites also have photocatalytic performance and were able to produce • OH under light irradiation [eq 8].…”
Single activation of peroxymonosulfate (PMS) in a homogeneous system is sometimes insufficient for producing reactive oxygen species (ROS) for water treatment applications. In this work, manganese spinel ferrite and graphitic carbon nitride (MnFe 2 O 4 /g-C 3 N 4 ; MnF) were successfully used as an activator for PMS under visible light irradiation to remove the four-mostdetected-hormone-contaminated water under different environmental conditions. The incorporation of g-C 3 N 4 in the nanocomposites led to material enhancements, including increased crystallinity, reduced particle agglomeration, amplified magnetism, improved recyclability, and increased active surface area, thereby facilitating the PMS activation and electron transfer processes. The dominant active radical species included singlet oxygen ( 1 O 2 ) and superoxide anions (O 2•− ), which were more susceptible to the estrogen molecular structure than testosterone due to the higher electron-rich moieties. The self-scavenging effect occurred at high PMS concentrations, whereas elevated constituent ion concentrations can be both inhibitors and promoters due to the generation of secondary radicals. The MnF/PMS/vis system degradation byproducts and possible pathways of 17β-estradiol and 17α-methyltestosterone were identified. The impact of hormone-treated water on Oryza sativa L. seed germination, shoot length, and root length was found to be lower than that of untreated water. However, the viability of both ELT3 and Sertoli TM4 cells was affected only at higher water compositions. Our results confirmed that MnF and visible light could be potential PMS activators due to their superior degradation performance and ability to produce safer treated water.
“…This is due to the various valences in the nanocomposites, including Mn 4+ , Mn 3+ , Mn 2+ , Fe 3+ , and Fe 2+ , which can trigger the synergistic action between the Mn and Fe redox cycles [10,11]. Furthermore, doping manganese ferrite structures with another transition metal (e.g., Cu) can produce ternary transition metal oxides (e.g., Cu 0.5 Mn 0.5 Fe 2 O 4 ), which have a greater surface area than iron-based transition metal catalysts [12,13]. This is beneficial to photo-Fenton-like AOP treatments by providing larger active sites, an excellent oxygen exchangeability, and an outstanding capability for electron transfer through the Cu 2+ /Cu 1+ redox cycle.…”
The amount of antibiotics and personal care products entering local sewage systems and ultimately natural waters is increasing and raising concerns about long-term human health effects. We developed an adsorptive photocatalyst, Cu0.5Mn0.5Fe2O4 nanoparticles, utilizing co-precipitation and calcination with melamine, and quantified its efficacy in removing paraben and oxytetracycline (OTC). During melamine calcination, Cu0.5Mn0.5Fe2O4 recrystallized, improving material crystallinity and purity for the adsorptive–photocatalytic reaction. Kinetic experiments showed that all four parabens and OTC were removed within 120 and 45 min. We found that contaminant adsorption and reaction with active radicals occurred almost simultaneously with the photocatalyst. OTC adsorption could be adequately described by the Brouers–Sotolongo kinetic and Freundlich isotherm models. OTC photocatalytic degradation started with a series of reactions at different carbon locations (i.e., decarboxamidation, deamination, dehydroxylation, demethylation, and tautomerization). Further toxicity testing showed that Zea mays L. and Vigna radiata L. shoot indexes were less affected by treated water than root indexes. The Zea mays L. endodermis thickness and area decreased considerably after exposure to the 25% (v/v)-treated water. Overall, Cu0.5Mn0.5Fe2O4 nanoparticles exhibit a remarkable adsorptive–photocatalytic performance for the degradation of tested antibiotics and personal care products.
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