| For dealing with the complex composition of industrial organic wastewater, biological toxicity of strong and poor biochemical problem, which is difficult to dispose by traditional physical, chemical and biological technology, new types of magnetic MFe2O4/C3N4 (M=Cu, Co) materials are prepared in this work, which can induce H2O2 to produce hydroxyl radical for the efficient degradation of persistent organic pollutants in wastewater. At present the main research contents as follows:(1) A new type of magnetic core-shell structure CuFe2O4@C3N4 compound Fenton-like oxidation degradation of Orange IINovel CuFe2O4@C3N4 photocatalysts are prepared by self-assembly synthesis. Analysis of physical and chemical properties of hybrid material evaluates the performance of degradation 0.028 mM Orange II under the condition of visible light with 0.01 M H2O2 as oxidant. Furthermore, when comparing these CuFe2O4@C3N4 hydrids at different contents of CuFe2O4, CuFe2O4@C3N4 (2:1) was found to show the best photocatalytic activity:nearly 98% of Orange II is decomposed within 210 min visible light irradiation. Factorial effects for the photocatalytic degradation performance of Orange II over CuFe2O4@C3N4 (2:1) under visible light irradiation, such as initial Orange II concentration (0.014-0.140 mM), different anions (Cl-, SO42-, NO3-, CH3COO- and HCO3-), reaction temperature (15-65 ℃), and so on. Different scavengers (Formate, TBA, IPA, BQ) were employed to elucidate photocatalytic mechanism in this study. As a result, it was reasonable to conclude that O2·-, ·OH and h+are responsible for the photocatalytic degradation. In addition, photogenerated holes are more important than the radicals for dye degradation. It was found that the photocatalytic activities of CuFe2O4@C3N4 (2:1) were barely declined after five cycling runs under visible light illumination, which can be effectively applied to photodegradation of organic pollutants.(2) Heterostructure CoFe2O4/C3N4 Z mechanism of hybrid material photo-Fenton reactionMagnetic heterostructure CoFe2O4/C3N4 hybrid materials are prepared by hydrothermal synthesis. Meticulous research of macroscopic and microscopic structure of the CoFe2O4/C3N4 hybrid materials make use of different detection methods, mainly including FESEM, HRTEM, EDS, XRD, FT-IR, TGA, BET, XPS, VSM, AAS, UV-DRS, etc. Factorial effects of catalyst activity also are made a more detailed investigation, such as different catalysts, various dyes (Methyl orange, Orange II, Methyl violet, Fuchsin basic, Methylene blue, RhB, Acid fuchsin and Malachite green), initial H2O2 concentration (0.01-0.50 M), FA concentration (5-50 mg/L), initial RhB concentration (5-20 mg/L), initial pH value (3-10) and different scavengers (Formate, TBA, PA and BQ), and so on. According to the result of photocatalytic degradation of organic dyes, the intensity of light can promote the effect of photocatalytic performance of samples, however, the greater intensity of irradiation light the higher requirement of experiment instruments. Comparison of the photocatalytic performance of samples, the CoFe2O4/C3N4 (2:1) sample shows the highest photocatalytic activity under room-light irradiation. The use of CoFe2O4/C3N4 (2:1) catalyst yielded a removal of 85.4% for Methyl orange,91.1% for Orange II,91.9% for Methyl violet,95.4% for Fuchsin basic, 100% for Methylene blue,98.2% for RhB,100% for Acid fuchsin and 100% for Malachite green under the similar operation conditions.In summary, a new practical reaction system of heterogeneous Fenton-like (MFe2O4/C3N4/H2O2/Vis) was provided to purify the dye wastewater in this paper. |
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