Energy-efficient fabrication of a novel multivalence Mn3O4-MnO2 heterojunction for dye degradation under visible light irradiation

Zhao, Jianhui; Nan, Jun; Zhao, Zhiwei; Li, Ning; Liu, Jie; Cui, Fuyi

doi:10.1016/j.apcatb.2016.09.065

Cited by 180 publications

(53 citation statements)

References 40 publications

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“…However, the main diffraction peaks of CM-700 were not matched exactly with that of MnFe 2 O 4 . The XRD pattern of CM-700 was coincident with the standard XRD patterns of Fe 3 O 4 (JCPDS 19-0629) 43 and Mn 3 O 4 (JCPDS 13-0162), 44,45 indicating that MnFe 2 O 4 decomposed at higher temperature and formed Fe 3 O 4 and Mn 3 O 4 .…”

Section: Characterization Of Catalystssupporting

confidence: 55%

Efficient degradation of Acid Orange 7 by persulfate activated with a novel developed carbon‐based MnFe₂O₄ composite catalyst

Liu

et al. 2019

J of Chemical Tech & Biotech

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BACKGROUND A novel carbon‐based modified MnFe2O4 catalyst was first developed to produce sulfate radicals (SO4−•) by activation of persulfate (PS). The catalyst was fabricated with a mixture of MnFe2O4 nanoparticles and chitosan (which could form a large amount of carbon‐based biomass after pyrolysis) annealed at 600 °C and was referred to as CM‐600. RESULTS The microstructure of the composite catalyst CM‐600 showed that MnFe2O4 was supported on the surface of carbon‐based sheets. After modification by pyrolysis, the specific surface area of MnFe2O4 enlarged significantly and thus the contact area between catalyst and PS increased. X‐ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy and X‐ray photoelectron spectroscopy were used to characterize the components of CM‐600. In comparison with the MnFe2O4/PS system, the activation of PS by CM‐600 was enhanced prominently, while 99.0% Acid Orange 7 (AO7) removal was achieved after reacting for 30 min. Investigations of influencing factors indicated the optimal treatment parameters. The two reactive species in the degradation process, namely free radicals (SO4−• and hydroxyl radicals (•OH)) and non‐radicals (singlet oxygen, 1O2), were confirmed by quenching tests and electron spin resonance spectroscopy. The corresponding degradation mechanism was proposed and SO4−• was generated primarily via the activation of PS by MnII and FeII. CONCLUSION The research demonstrated that the composite catalyst CM‐600 improved the property of MnFe2O4 for catalyzing PS and thus enlarged the practical application of SO4−• oxidation technology in pollutant degradation in aqueous environments. © 2019 Society of Chemical Industry

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Section: Characterization Of Catalystssupporting

confidence: 55%

Efficient degradation of Acid Orange 7 by persulfate activated with a novel developed carbon‐based MnFe₂O₄ composite catalyst

Liu

et al. 2019

J of Chemical Tech & Biotech

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“…Additionally, a possible excitation mechanism of TiO 2 –MnO 2 NTs under Vis light was proposed and diagrammed in Figure 8 b. The conduction band and valence band edge values of MnO 2 were calculated to be 0.57 and 2.34 eV, respectively [ 34 ]. Thus, it is likely that photogenerated holes from the valence band (VB) of MnO 2 could be involved in the formation of hydroxyl radicals ( • OH), while electrons from the CB of MnO 2 can participate indirectly in the degradation of toluene, considering that the potential of photogenerated electrons is not high enough to generate other reactive oxygen species, such as O 2 •− , H 2 O 2 , and HO 2 • radicals.…”

Section: Resultsmentioning

confidence: 99%

“…Recent studies have focused on TiO 2 –MnO 2 system due to the MnO 2 features as non-toxicity and earth abundance. These composites have been used mainly for capacitance applications [ 31 , 32 ], and despite the narrow bandgap of MnO 2 (0.26–2.7 eV), which could allow the absorption of visible and theoretically even infrared light [ 33 , 34 , 35 , 36 , 37 , 38 ], there exist just few reports in literature about the application of this system in photocatalysis. Xue, et al [ 39 ] synthesized mesoporous MnO 2 /TiO 2 nanocomposite, photoactive for the visible light-driven degradation of MB.…”

Section: Introductionmentioning

confidence: 99%

Self-Organized TiO2–MnO2 Nanotube Arrays for Efficient Photocatalytic Degradation of Toluene

et al. 2017

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Vertically oriented, self-organized TiO2–MnO2 nanotube arrays were successfully obtained by one-step anodic oxidation of Ti–Mn alloys in an ethylene glycol-based electrolyte. The as-prepared samples were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), UV-Vis absorption, photoluminescence spectroscopy, X-ray diffraction (XRD), and micro-Raman spectroscopy. The effect of the applied potential (30–50 V), manganese content in the alloy (5–15 wt. %) and water content in the electrolyte (2–10 vol. %) on the morphology and photocatalytic properties was investigated for the first time. The photoactivity was assessed in the toluene removal reaction under visible light, using low-powered LEDs as an irradiation source (λmax = 465 nm). Morphology analysis showed that samples consisted of auto-aligned nanotubes over the surface of the alloy, their dimensions were: diameter = 76–118 nm, length = 1.0–3.4 μm and wall thickness = 8–11 nm. It was found that the increase in the applied potential led to increase the dimensions while the increase in the content of manganese in the alloy brought to shorter nanotubes. Notably, all samples were photoactive under the influence of visible light and the highest degradation achieved after 60 min of irradiation was 43%. The excitation mechanism of TiO2–MnO2 NTs under visible light was presented, pointing out the importance of MnO2 species for the generation of e− and h+.

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“…For the former, the binding energies of approximately 529.7, 531.1, and 531.7 eV was separately caused by the bulk oxygen of MnO 2 , surface hydroxyl bonded to Mn, and absorbed oxygen. Nevertheless, for the latter, another extraordinary peak at 530.2 eV was detected in addition to the three binding energies above, which originated from the existence of lattice oxygen of Mn 3 O 4 [43]. This also demonstrated that the photocatalyst consisted of Mn 3 O 4 and MnO 2 .…”

Section: Characterization Of the Photocatalystmentioning

confidence: 76%

“…In addition, MnO 2 and Mn 3 O 4 could constitute a heterojunction structure. Photogenerated carriers could be effectively separated in heterojunctions, which enhanced photocatalytic performance [43]. For the photocatalytic test, Fe 3 O 4 /MnO 2 /Mn 3 O 4 microspheres had better catalytic performance than Fe 3 O 4 /MnO 2 microspheres, which indicated that the composite of MnO 2 and Mn 3 O 4 could significantly enhance the photocatalytic performance.…”

Section: Photocatalytic Testsmentioning

confidence: 94%

Synthesis of Hollow Flower-Like Fe3O4/MnO2/Mn3O4 Magnetically Separable Microspheres with Valence Heterostructure for Dye Degradation

Yang

Chen

et al. 2019

Catalysts

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In this manuscript, hollow flower-like ferric oxide/manganese dioxide/trimanganese tetraoxide (Fe3O4/MnO2/Mn3O4) magnetically separable microspheres were prepared by combining a simple hydrothermal method and reduction method. As the MnO2 nanoflower working as precursor was partially reduced, Mn3O4 nanoparticles were in situ grown from the MnO2 nanosheet. The composite microspheres were characterized in detail by employing scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), vibration sample magnetometer (VSM) and UV–visible spectrophotometer (UV–vis). Under visible light conditions, the test for degrading rhodamine B (RhB) was used to verify the photocatalytic activity of the photocatalyst. The results showed that the efficiency of the Fe3O4/MnO2/Mn3O4 photocatalyst in visible light for 130 min is 94.5%. The catalytic activity of photocatalyst far exceeded that of the Fe3O4/MnO2 component, and after four cycles, the catalytic performance of the catalyst remained at 78.4%. The superior properties of the photocatalyst came from improved surface area, enhanced light absorption, and efficient charge separation of the MnO2/Mn3O4 heterostructure. This study constructed a green and efficient valence heterostructure composite that created a promising photocatalyst for degrading organic contaminants in aqueous environments.

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Energy-efficient fabrication of a novel multivalence Mn3O4-MnO2 heterojunction for dye degradation under visible light irradiation

Cited by 180 publications

References 40 publications

Efficient degradation of Acid Orange 7 by persulfate activated with a novel developed carbon‐based MnFe₂O₄ composite catalyst

Efficient degradation of Acid Orange 7 by persulfate activated with a novel developed carbon‐based MnFe₂O₄ composite catalyst

Self-Organized TiO2–MnO2 Nanotube Arrays for Efficient Photocatalytic Degradation of Toluene

Synthesis of Hollow Flower-Like Fe3O4/MnO2/Mn3O4 Magnetically Separable Microspheres with Valence Heterostructure for Dye Degradation

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Energy-efficient fabrication of a novel multivalence Mn3O4-MnO2 heterojunction for dye degradation under visible light irradiation

Cited by 180 publications

References 40 publications

Efficient degradation of Acid Orange 7 by persulfate activated with a novel developed carbon‐based MnFe2O4 composite catalyst

Efficient degradation of Acid Orange 7 by persulfate activated with a novel developed carbon‐based MnFe2O4 composite catalyst

Self-Organized TiO2–MnO2 Nanotube Arrays for Efficient Photocatalytic Degradation of Toluene

Synthesis of Hollow Flower-Like Fe3O4/MnO2/Mn3O4 Magnetically Separable Microspheres with Valence Heterostructure for Dye Degradation

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Efficient degradation of Acid Orange 7 by persulfate activated with a novel developed carbon‐based MnFe₂O₄ composite catalyst

Efficient degradation of Acid Orange 7 by persulfate activated with a novel developed carbon‐based MnFe₂O₄ composite catalyst