CHEMOSPHERE
·
2018
·
IF 4.427
Hengduo Xu,Xiangchun Quan,Liang Chen
Advanced oxidation process (AOP) based on peroxymonosulfate (PMS) activation was established in microbial fuel cell (MFC) system with MnFe 2 O 4 cathode (MFC-MnFe 2 O 4 /PMS) aimed to enhance azo dye degradation and catalyst regeneration. The effects of loading amount of MnFe 2 O 4 catalyst, applied voltage, catholyte pH and PMS dosage on the degradation of Orange II were investigated. The stability of the MnFe 2 O 4 cathode for successive PMS activation was also evaluated. The degradation of Orange was accelerated in the MFC-MnFe 2 O 4 /PMS with apparent degradation rate constant increased to 1.8 times of that in the MnFe 2 O 4 /PMS control. A nearly complete removal of Orange II (100 mg L −1 ) was attained in the MFC-MnFe 2 O 4 /PMS under the optimum conditions of 2 mM PMS, 10 mg cm −2 MnFe 2 O 4 loading, pH 7–8 and 480 min reaction time. MFC driven also extended the longevity of the MnFe 2 O 4 catalyst for PMS activation due to the in-situ regeneration of ≡Mn 2+ and ≡Fe 2+ through accepting electrons from the cathode, and over 80% of Orange II was still removed in the 7 th run. Additionally, the MFC-MnFe 2 O 4 /PMS system could recover electricity during Orange II degradation with a maximum power density of 206.2 ± 3.1 mW m −2 . PMS activation by MnFe 2 O 4 was the primary pathway for SO 4 - generation, and SO 4 - based oxidation was the primary mechanism for Orange II degradation. MFCs driven coupled with PMS activated AOP systems provides a novel strategy for efficient and persistent azo dye degradation.
研究领域:
环境科学
·
生物电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Yixi Sun,Jiabin Zhou,Dan Liu,Xi Li,Hong Liang
It is important to develop a catalyst that can maintain good activity in alkaline environment for Fenton or Fenton-like reactions. In order to achieve stable Fenton catalytic degradation in a wide pH range, this study reports Cu-doped MnFe 2 O 4 heterogeneous catalysts still has excellent effect when the pH is extended to 11 for removing organic pollutants, such as tetracycline hydrochloride (TC-HCl). The synergistic effect among Fe, Mn and Cu ions has been proved to enhanced the catalytic activity in this work. When the molar ratio of Cu/Mn = 4:1, the porous Cu 0·8 Mn 0·2 Fe 2 O 4 materials had the highest photo-Fenton catalytic activity compared with pure MnFe 2 O 4 , CuFe 2 O 4 and other Cu x Mn 1-x Fe 2 O 4 . The XPS showed that Cu 0·8 Mn 0·2 Fe 2 O 4 formed oxygen vacancies, which exposed more active sites to attract more H 2 O 2 for TC-HCl degradation. Results indicated 94.3% of TC-HCl was efficiently degraded by 0.1 g/L Cu 0·8 Mn 0·2 Fe 2 O 4 with 50 mM H 2 O 2 at pH = 11 under 30 min visible light irradiation, and the corresponding apparent rate constant was 0.08286 min −1 . With free radicals quenching experiment, O 2 − was responsible for the high catalytic degradation and OH was participated in the photo-Fenton reaction. To sum up, Cu 0·8 Mn 0·2 Fe 2 O 4 exhibited high activity, great stability and easily recyclable, which eliminated the pH limitation of the Fenton reaction and provided practical application performance for water purification .
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
P. Ning,C.C. Liu,Y.J. Wang,X.Z. Li,R. Ranjithkumar,Z.H. Gan,Y.Y. Wu,T. Fu
Magnetic MnFe 2 O 4 nanoparticles containing 0, 1 and 3 at.% silver, respectively were synthesized by one-pot sol-gel method for antibacterial applications in biomedical fields. Material characterizations indicate that MnFe 2 O 4 begins crystallization at 134 °C and oxidation at 450 °C, the grain size and agglomeration degree increase with the silver content and silver exists as metallic state for the particles. The saturation magnetization decreases with the sintering temperature and slightly increases with the silver content, with the maximum of 50.0 emu/g obtained. Antibacterial tests by plate counting and PI-Hoechst 33342 staining suggest that the antibacterial activity of Ag–MnFe 2 O 4 nanoparticles is silver content-dependent. Silver ions concentration measurement, β-galactosidase activity assay and transmission electron microscopic observation show that the antibacterial activity is dominated by the actions of the released silver ions, rather than the membrane cell impairment or reactive oxygen species-induced oxidative stress mechanism. MC3T3-E1 cell test demonstrates the best cytocompatibility of the nanoparticles with 3 at.% silver, which is likely related to the reduced cell endocytosis of the aggregated particles. The combination of magnetism , antibacterial activity and biocompatibility would make Ag–MnFe 2 O 4 nanoparticles a potential multi-functional material in various biomedical applications.
研究领域:
材料科学
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纳米技术
·
生物医学工程
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Zhipan Wen,Jiangbo Xi,Jun Lu,Yalei Zhang,Gang Cheng,Yuhan Zhang,Rong Chen
To solve the problem of organic and inorganic arsenic species contamination in drinking water and/or wastewater, porous biochar-supported MnFe 2 O 4 magnetic nanocomposite (BC-MF) was successfully fabricated and used as an excellent adsorbent for simultaneous removal of p -ASA and As(V) from water environment. This obtained BC-MF displayed remarkable adsorption performance for both p -ASA and As(V) removal at acidic and neutral pH (3−7), and di-anionic and mono-anionic species of p -ASA and As(V) facilitated the adsorption process . Specifically, BC-MF exceeded some reported adsorbents, and the adsorption capacities of p -ASA and As(V) were approximately 105 and 90 mg/g at a 10 μg/L equilibrium concentration. Satisfactory adsorption behavior including adsorption isotherms , competitive ions, humic acid (HA), and regeneration/reusability property in single and binary systems demonstrated the BC-MF can improve the potential application for arsenic-containing wastewater remediation. Proposed adsorption mechanism indicated that electrostatic interaction and surface complexation were involved the p -ASA and As(V) immobilization, whereas hydrogen bonding and π-π interactions may also contribute to the p -ASA removal. Additionally, the prominent sequestration p -ASA and As(V) performance in different water matrix and fixed-bed column studies indicated that BC-MF was a promising nanocomposite for simultaneously removal of organic and inorganic arsenic species in practical wastewater treatment .
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemElectroChem
·
2017
·Vol. 4
·期 10
·2500-2506
·
IF 4.136
Yao Du,Chun Liu,Shuijing Sun,Songping Wu
Graphical Harsh reality : A facile solution route to monodisperse MnO@3MnFe 2 O 4 @rGO is established. As anode materials of Li-ion batteries, MnO@3MnFe 2 O 4 @rGO delivers remarkable cycling performances. Therefore, MnO@3MnFe 2 O 4 @rGO nanocomposites can be considered promising battery materials that can be operated in harsh environments. A facile high-temperature solution route to a monodisperse core-shell structure of MnO (core) and MnFe 2 O 4 (shell) (abbreviated as MFO) nanoparticles anchored on reduced graphene oxide (rGO) has been established. Subsequently, MnO@MnFe 2 O 4 @rGO nanocomposites are utilized as advanced anode materials for high-performance Li-ion batteries. MnO@3MFO@rGO containing 22.5 wt% of the rGO composite (with a 1 : 3 molar ratio of MnO/MFO) as the electrodes delivered a remarkable cycling performance, that is, 587.8 mAh g −1 at a current density of 200 mA g −1 after 200 cycles at ambient temperature with an ultralow capacity fading (0.10 % per cycle). More importantly, the electrodes afforded excellent capacity stability under various operation temperatures (ca. −20 to 70 °C), such as an excellent reversible capacity of 1067 mA h g −1 at a current density of 500 mA g −1 after 300 cycles at 60 °C, and remarkable low-temperature performance of a reversible capacity of 208.7 mA h g −1 at a current density of 200 mA g −1 at −20 °C. Therefore, MnO@3MFO@rGO nanocomposites are considered as promising battery materials that can be operated in harsh environments.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2021
·Vol. 79
·期 2
·1201-1216
·
IF 2.87
Yu Changjiang,Li Han,Ma Haoyue,Zhang Limei,Li Yu,Lin Qiang
A magnetic composite microsphere, calcium alginate (CA)/carboxymethyl cellulose (CMC)@MnFe 2 O 4, was prepared using CA and CMC encapsulated MnFe 2 O 4 through blending and cross-linking for the removal of Cu(II) from aqueous solution. The CA/CMC@MnFe 2 O 4 was characterized in detail by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and X-ray phosphorescence spectroscopy. In addition, various adsorption conditions including the initial pH of Cu(II) solution, equilibrium contact time, and initial Cu(II) concentration were tested. The adsorption data fit better to the Langmuir isotherm and follow the pseudo-second-order model, suggesting that it is a monolayer adsorption process with chemisorption as the rate-limiting step. The maximum adsorption capacity of the CA/CMC@MnFe 2 O 4 was 77.22 mg g −1 at 25 ℃ and pH 5. Cu(II) removal mechanisms of CA/CMC@MnFe 2 O 4 follow ion exchange as well as the formation of complexes as evidenced based on the microstructure analysis and adsorption data fitting.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Xian Yang,Liuting Zeng,Jinjia Huang,Zhihua Mo,Zhijie Guan,Shuiyu Sun,Jialin Liang,Shaosong Huang
The high moisture content of sludge is a key factor limiting its subsequent treatment and disposal. Herein, a novel method of MnFe 2 O 4 -biochar (MFB) activated peroxymonosulfate (PMS) combined with tannic acid (TA) was conducted to improve sludge dewatering . The effects of different concentrations of MFB, PMS, and TA on waste activated sludge (WAS) dewaterability were investigated. The water content of sludge cake dropped to 40.80% when the initial pH was 5.0, and the concentration of PMS, MFB, and TA was 0.64 mM/g DS, 100 mg/g DS, and 0.12 mM/g DS respectively, demonstrating that MFB/PMS/TA could effectively enhance sludge dewaterability. Analyzing the changing of sludge properties and characterizing MFB confirmed that the enhancement of sludge dewaterability occurred in two phases. First, TA accelerated the valence transformation of Fe and Mn to promote PMS activation, which strengthened the oxidation capacity of the system. Second, TA complexed and precipitated protein to enhance the compressibility and dewaterability of sludge. Furthermore, MFB/PMS/TA treatment could increase the calorific value of treated sludge, and after the combined treatment, the sludge biochar also had a better pore structure, indicating that the sludge after the combined treatment posed a good prospect of resource utilization. These findings provide a novel strategy for the practical application of achieving efficient sludge deep dewatering, providing a valuable reference for downstream sludge utilization .
研究领域:
环境工程
·
水处理
·
废物管理
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Siyu Xu,Liangtao Wen,Chen Yu,Song Li,Jingchun Tang
In this study, novel metallic oxide catalyst MnFe 2 O 4 @biochar composite was synthesized by sol–gel pyrolysis loading of MnFe 2 O 4 on biochar, and then used to activate peroxymonosulfate (PMS) to degrade bisphenol A (BPA). Characterization results demonstrated that the Fe and Mn oxide particles were homogeneously distributed on the surface of biochar, which avoided the aggregation of metal oxides. The strong magnetism of the composite was conducive to recycling during practical application. In the PMS system activated by MnFe 2 O 4 @biochar composite, the removal rate and mineralization rate of 20 mg/L BPA reached 100% and 95.9% within 30 min, respectively. The quenching experiments and electron paramagnetic resonance (EPR) study verified the coexistence of free-radical and non-radical pathways in the MnFe 2 O 4 @biochar/PMS system, with O 2 •- as the dominant active species, followed by singlet oxygen ( 1 O 2 ). The catalytic degradation process could adapt a wide pH range from weak acid to the alkaline matrix and showed negligible influence by anions and humic acid. The characterization results confirmed the synergistic effect of the bimetal, proving that the introduction of biochar and second metal source into iron-based catalyst played an important role in the composite. Overall, the MnFe 2 O 4 @biochar showed promising performance in activating PMS for organic pollutant degradation in water with high stability and safe performance.
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Qiuling Ma,Huixuan Zhang,Xinyi Zhang,Bo Li,Ruonan Guo,Qingfeng Cheng,Xiuwen Cheng
Magnetic CuO/MnFe 2 O 4 nanocomposite were synthesized and characterized as a heterogeneous catalyst. Subsequently, it was used to activate persulfate (PS) for levofloxacin (LVF) removal with the operating parameters optimized. Results reveled that the sample of CuO/MnFe 2 O 4 -9% showed higher catalytic performance than pure CuO, pure MnFe 2 O 4 and other fabricated CuO/MnFe 2 O 4 nanocomposites. And under the optimized conditions of 1 g·L −1 CuO/MnFe 2 O 4 -9% and PS at pH 9 and 25 °C, 91.3% of LVF could be decomposed within 120 min. Besides, the underlying mechanism of CuO/MnFe 2 O 4 nanocomposite activating PS was proposed by free radical quenching experiment and XPS results. Eventually, several degradation intermediates of LVF were identified and three decomposition pathways were proposed. Especially, the CuO/MnFe 2 O 4 nanocomposite exhibited superparamagnetic property and good stability, which favored the catalyst to be efficiently recovered through the applied magnetic field and reused from aquatic environment. Thus, the as-prepared CuO/MnFe 2 O 4 nanocomposite might be applied to the removal of refractory organics in environmental remediation.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2021
·Vol. 11
·期 12
·1550
·
IF 4.146
Hongzhou Dong,Yingjie Chen,Chong Gong,Lina Sui,Qiong Sun,Kangle Lv,Lifeng Dong
Due to slow kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) during discharging and charging processes, it is essential to rationally design and synthesize non-precious metal bifunctional electrocatalysts with good performance for metal-air batteries. Herein, Ag-MnFe2O4heterojunction nanoparticles supported on N, S, P-codoped graphene (NSPG) are developed with enhanced ORR and OER bifunctional electrocatalytic activities and stability. In contrast, S, P-doped graphene (SPG) and N, P-doped graphene (NPG) show less stabilization for the heterojunction particles. For example, under alkaline conditions, the ORR half-wave potential of Ag-MnFe2O4/NSPG can reach 0.831 V, and the over potential for OER is 0.56 V at the current density 10 mA·cm−2. Furthermore, Ag-MnFe2O4/NSPG shows better methanol resistance and durability than Pt/C catalysts.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 5
·1276
·
IF 5.076
Qian Li,Xiaoyu Jiang,Yongfu Lian
The MnFe2O4/BGA (boron-doped graphene aerogel) composite was prepared by hydrothermal treatment of MnFe2O4particles, boric acid, and graphene oxide. When applied as a photo-Fenton catalyst for the degradation of rhodamine B, the MnFe2O4/BGA composite yielded a degradation efficiency much higher than the sum of those of individual MnFe2O4and BGA under identical experimental conditions, indicating a strong synergetic effect established between MnFe2O4and BGA. The catalytic degradation of rhodamine B was proved to follow pseudo first-order kinetics, and the apparent reaction rate constant on the MnFe2O4/BGA composite was calculated to be three- and seven-fold that on BGA and MnFe2O4, respectively. Moreover, the MnFe2O4/BGA composite also demonstrated good reusability and could be reused for four cycles without obvious loss of photocatalytic activity.Keywords:manganese ferrite;boron-doped graphene aerogel;degrading efficiency
研究领域:
环境科学
·
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Haichao Fu,Shuanglong Ma,Peng Zhao,Shengjun Xu,Sihui Zhan
Three novel graphitized hierarchical porous biochar (MX) and MnFe 2 O 4 magnetic composites (MnFe 2 O 4 /MX) have been prepared for degrading organic pollutants by peroxymonosulfate (PMS) activation. MX including MS, ML, MC synthesized using corn stems (S), leaves (L) and cores (C) as raw materials, respectively, possesses hierarchical porous structure, graphitization domains and tremendous surface area. The orange II removal effects of MX and MnFe 2 O 4 /MX outperform the corresponding carbonization products, despite that adsorption probably undertakes the major removal efficiency for MX and degradation contributes the most for MnFe 2 O 4 /MX. A structure-dependent degradation efficiency is discovered for MX and MnFe 2 O 4 /MX, among of which both MS and MnFe 2 O 4 /MS present the best removal effect, by electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). The lowest EIS owning to its better balance between graphitization degree and specific surface area and micropore volume of MnFe 2 O 4 /MS among MnFe 2 O 4 /MX explains its best catalytic activity. The catalytic degradation occurs by the following three ways. First, the radical-induced oxidation is attained by surface-bound SO 4 − and OH on MnFe 2 O 4 nanoclusters and hierarchical porous carbon nanosheets generated by one-electron reduction of PMS under the participating and coupling of Mn(III)/Mn(II), Fe(III)/Fe(II), O 2 / O 2 − , and active sites on carbon surface. Second, non-radical pathway involves the contribution of 1 O 2 , which is produced in a large quantity by promoted self-decomposition of PMS in presence of MnFe 2 O 4 /MS. Third, non-radical pathway is achieved through electron transfer from organic compounds as electron donator to PMS as electron acceptor mediated by graphitization structures. Taking into consideration the excellent degradation performance, easy magnetic separation, and bulk availability of MnFe 2 O 4 /MS, this work is expected to pave a new way for precision utilization of corn biomass-based biochar for environmental application.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）