Decomposition Of Bisphenol Research Articles

Self-Assembled FeIII-TAML-Based Magnetic Nanostructures for Rapid and Sustainable Destruction of Bisphenol A.

This study focused on constructing iron(III)-tetraamidomacrocyclic ligand (FeIII-TAML)-based magnetic nanostructures via a surfactant-assisted self-assembly (SAS) method to enhance the reactivity and recoverability of FeIII-TAML activators, which have been widely employed to degrade various organic contaminants. We have fabricated FeIII-TAML-based magnetic nanomaterials (FeIII-TAML/CTAB@Fe3O4, CTAB refers to cetyltrimethylammonium bromide) by adding a mixed solution of FeIII-TAML and NH3·H2O into another mixture containing CTAB, FeCl2 and FeCl3 solutions. The as-prepared FeIII-TAML/CTAB@Fe3O4 nanocomposite showed relative reactivity compared with free FeIII-TAML as indicated by decomposition of bisphenol A (BPA). Moreover, our results demonstrated that the FeIII-TAML/CTAB@Fe3O4 composite can be separated directly from reaction solutions by magnet adsorption and reused for at least four times. Therefore, the efficiency and recyclability of self-assembled FeIII-TAML/CTAB@Fe3O4 nanostructures will enable the application of FeIII-TAML-based materials with a lowered expense for environmental implication.

Insights into the mechanism of g-C3N4@a-Fe2O3 microsphere heterogeneous activation of hydrogen peroxide under visible light

A-Fe2O3 complex g-C3N4@a-Fe2O3 was successfully prepared by solvothermal method and used in optical Fenton photocatalytic process. Using experimental instruments such as XPS, XRD, DRS, TEM, FTIR, and photochemistry to characterize composite materials. According to the mechanism of the photocatalytic process, combining A-Fe2O3/H2O2 Fenton reagent with g-C3N4 photocatalyst under visible light conditions can effectively accelerate the mineralization of pollutants. The photocatalytic performance of g-C3N4@a-Fe2O3 were evaluated by the decomposition of bisphenol A. When the content of a-Fe2O3 is 15%, the photocatalytic efficiency of the composite is the highest. In addition, cyclic operation, iron leaching concentration, fresh and XRD pattern studies indicate that g-C3N4@a-Fe2O3 composites are very stable and reusable. The results show that the decomposition of BPA by persulfate is a non-free radical reaction, but the coupling a-Fe2O3 with g-C3N4 can effectively activate the formation of persulfate free radicals and reduce BPA under visible light radiation. Studies showed that free radicals generated by electron holes and persulfate formed on catalysts were the main causes of BPA decomposition. Therefore, combined with previous research results, this paper proposed the mechanism of g-C3N4@a-Fe2O3 composite photocatalytic reaction by photo-Fenton. More importantly, this work demonstrates a novel approach to activate persulfates that can efficiently degrade pops and gives some new ideas on the remediation of persulfates in contaminated Water.

Insights into the mechanism of g-C3N4@a-Fe2O3 microsphere heterogeneous activation of hydrogen peroxide under visible light

A-Fe2O3 complex g-C3N4@a-Fe2O3 was successfully prepared by solvothermal method and used in optical Fenton photocatalytic process. Using experimental instruments such as XPS, XRD, DRS, TEM, FTIR, and photochemistry to characterize composite materials. According to the mechanism of the photocatalytic process, combining A-Fe2O3/H2O2 Fenton reagent with g-C3N4 photocatalyst under visible light conditions can effectively accelerate the mineralization of pollutants. The photocatalytic performance of g-C3N4@a-Fe2O3 were evaluated by the decomposition of bisphenol A. When the content of a-Fe2O3 is 15%, the photocatalytic efficiency of the composite is the highest. In addition, cyclic operation, iron leaching concentration, fresh and XRD pattern studies indicate that g-C3N4@a-Fe2O3 composites are very stable and reusable. The results show that the decomposition of BPA by persulfate is a non-free radical reaction, but the coupling a-Fe2O3 with g-C3N4 can effectively activate the formation of persulfate free radicals and reduce BPA under visible light radiation. Studies showed that free radicals generated by electron holes and persulfate formed on catalysts were the main causes of BPA decomposition. Therefore, combined with previous research results, this paper proposed the mechanism of g-C3N4@a-Fe2O3 composite photocatalytic reaction by photo-Fenton. More importantly, this work demonstrates a novel approach to activate persulfates that can efficiently degrade pops and gives some new ideas on the remediation of persulfates in contaminated Water.

Gd3+ doped BiVO4 and visible light-emitting diodes (LED) for photocatalytic decomposition of bisphenol A, bisphenol S and bisphenol AF in water

The photocatalytic efficiency of BiVO4 was enhanced through rare-earth doping (Gd3+). The effect of different concentrations of Gd3+ was evaluated through the decomposition of bisphenol A in water. To better understand the photocatalytic properties of the synthesized photocatalysts, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), and Brunauer-Emmett-Teller (BET) method were applied. It was found that 4% of Gd3+ in molar mass showed the best photocatalytic efficiency. Decomposition of bisphenol A, bisphenol S, and bisphenol AF was studied using the photocatalyst with the optimal concentration of Gd3+, reaching decomposition percentages up to 77.02% ± 2.16, 44.36% ± 2.74%, and 74.11% ± 5.09, respectively after three hours reaction. Reactive species were identified by scavenging tests and additionally, kinetic studies were performed. A decomposition pathway was proposed for the three studied pollutants. The synthesized Gd3+ doped BiVO4 photocatalysts demonstrated to be a promising alternative for the efficient degradation of disrupting endocrine compounds such as bisphenol A analogs present in water using LED visible light as an eco-friendly irradiation source.

Efficient removal of bisphenol A and disinfection of waterborne pathogens by boron/nitrogen codoped graphene aerogels via the synergy of adsorption and photocatalysis under visible light

It is widely acknowledged that doping of carbon materials by multi-elements with different electronegativities can result in unique electron-donor properties and novel functionalities because of the strong synergistic interaction among the dopant atoms. In this study, boron and nitrogen codoped graphene aerogels (BNGAs) are synthesized and their photocatalytic activity towards decomposition of bisphenol A (BPA) under visible light irradiation is systematically examined. The BPA molecules are rapidly adsorbed onto the 3D interconnected pore system of the BNGAs under dark conditions, and eventually mineralized upon exposure to visible light, indicating the synergy between adsorption-enrichment and photocatalysis during degradation of BPA. Notably, almost 96 % of BPA is removed and over 88 % of total organic carbon is eliminated by the as-prepared BNGAs. More importantly, the BNGAs can retain approximately 92 % of their initial activity even after repeated cycling. In addition, the BNGAs display great potential for the disinfection of harmful pathogens like Escherichia coli, with a photocatalytic decontamination rate of 1.2 × 103 CFU h−1 gcat−1. In view of their attractive multi-functional performance, the as-developed BNGAs merit further consideration for eliminating emerging organic contaminants and pathogens from freshwater sources.

Sulfur promoted n-π* electron transitions in thiophene-doped g-C3N4 for enhanced photocatalytic activity

Expanding the optical absorption range of photocatalysts is still a key endeavor in graphitic carbon nitride (g-C3N4) studies. Here, we report on a novel thiophene group extending the optical property, which is assigned to n-π* electronic transitions involving the two lone pairs on sulfur (TLPS). The as-prepared samples, denoted as CN-ThAx (where x indicates the amount of ThA added, mg), showed an additional absorption above 500 nm as compared to pristine g-C3N4. Further, the thiophene group enhanced charge carrier separation to suppress e−/h+ pair recombination. The experimental results suggest that the thiophene group can obstruct the polymerization of melem to generate a large plane, thus exposing the lone electron pairs on the sulfur. The photocatalytic activity was evaluated in the decomposition of bisphenol A and H2 evolution. Compared with g-C3N4, the optimized CN-ThA30 sample led to a 6.6- and 2-fold enhancement of the degradation and H2 generation rates, respectively. The CN-ThA30 sample allowed for synchronous H2 production and BPA decomposition.

Kinetics of the Photocatalytic Decomposition of Bisphenol A on Modified Photocatalysts

Kinetics of the Photocatalytic Decomposition of Bisphenol A on Modified Photocatalysts

Sustainable periodically patterned carbon nanotube for environmental application: Introducing the cheetah skin structure

Abstract Advanced Oxidation Processes (O 3 - and H 2 O 2 - assisted photocatalysis under Vis irradiation) were applied for the removal of recalcitrant pollutant from wastewater. The new periodically patterned carbon nanotube entitled cheetah skin structure introduced for the first time. The photocatalytic activity of cheetah skin CNT modified by poly (methyl methacrylate) (PMMA) and polyacrylonitrile (PAN) was tested in the decomposition of bisphenol A (BPA). The obtained CNT/PAN/PMMA composites differ in morphological structure. In PAN/CNT composite, a tubular coating was formed and a continuous coating layer of PAN on the surface of nanotubes was observed. In PAN/PMMA/CNT composite after carbonization process, the PMMA was completely evaporated and Carbon Nano Particles (CNP) with circular morphology in order of less than 10 nm were coated on the surface of nanotube walls forming a cheetah skin structure. The presence of CNP led to significant increase in degradation temperature. The application of tested nanocomposites enabled a significant removal of BPA. The highest changes in water pollution were observed during first 20 min of treatment. Nanocomposite containing 1.5% PAN - 0.5%PMMA demonstrated the best activity. During photo enhanced ozonation almost 90–95% of BPA was removed. H 2 O 2 slightly increased oxidation under Vis irradiation. The removal of BPA proceeded according to a pseudo-first order regime. Toxicity of BPA was significantly reduced after treatment and applied procedures enabled to obtain high quality non-toxic water. The obtained results clearly indicate that novel PAN-PMMA modified CNT could be a promising candidate for the photo mineralization of BPA.

A Comparison between the Decomposition of Bisphenol A and the Concentration of Hydrogen Peroxide Formed during Ozone/Catalyst Oxidation Process

A Comparison between the Decomposition of Bisphenol A and the Concentration of Hydrogen Peroxide Formed during Ozone/Catalyst Oxidation Process

Change of toxicity of water containing bisphenol A during its treatment by complex oxidation process

Water containing bisphenol A was UV irradiated (medium pressure immersion lamp with the electric power of 150 W) with and without the addition of H2O2 (6–12 mg/dm 3 dose). To control of the water quality Microtox biotest was used. Bioluminescent bacteria Vibrio fisheri was involved. Decomposition of bisphenol A was depended on the UV irradiation time and dose of the H2O2. The observations connected with the bioluminescence value in the examined solutions were surprised. Decomposition of the compound did not cause of decrement the bioluminescence inhibition value characterizing solution indicating the formation of toxic intermediates products. However, the combined use of H2O2 with UV radiation improves the rate of decomposition of bisphenol A, but also causes an increase in bioluminescence inhibition of the solutions. For this reason selection of the most favorable conditions for the oxidative process have to be proceed based on both agents: effectiveness of the compounds decomposition and the toxicity of the solution after process.

The Decomposition of Bisphenol a Diglycidyl Ether/Alicyclic Amine Hardened Networks in Near-critical Water

The decomposition of bisphenol A diglycidyl ether/alicyclic amine hardened networks in near-critical water was studied in this paper. It is possible to decompose thermosetting epoxy resin completely at 260 °C for 1 h with 1 g/5 ml feedstock ratio. The decomposition rate of epoxy resin increased with an increase in reaction temperature. The decrease in sample size led to higher decomposition rate, and the catalysts NH4Cl and H2SO4 had the higher positive effect on the decomposition rate. Thermogravimetry analysis (TGA) showed that thermal decomposition was not the primary factor for the collapse of networks in the temperature range studied. Gas Chromatography-Mass Spectrometry (GC-MS) showed the main components of the soluble decomposed compounds were bisphenol A, hydroxybenzene, olefin and ketone compounds and their content varied during the reaction. The hydrolysis of ether bond was regarded as the key factor in the process of decomposition reaction of bisphenol A diglycidyl ether/alicyclic amine hardened networks.

酸性電解水によるビスフェノールＡの分解

酸性電解水によるビスフェノールＡの分解

Determination of the equilibrium constant for the reaction between bisphenol A and diphenyl carbonate

AbstractDespite the industrial significance of poly(bisphenol A carbonate), there is a scarcity of open literature on the equilibrium of the melt‐phase process. In fact, the equilibrium constant (Keq) for this reaction has never been measured directly. This article describes a process on the basis of NMR for the measurement of Keq for the reaction between bisphenol A and diphenyl carbonate in the presence and absence of a catalyst. The apparent enthalpy and entropy were calculated using a van't Hoff plot. Decomposition of bisphenol A is a common side reaction in the melt‐phase reaction performed at high temperatures in the presence of catalyst. The effect of these side reactions on the Keq in the presence of catalyst is determined. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 171–178, 2002