APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Qizhao Wang,Jijuan He,Yanbiao Shi,Shuling Zhang,Tengjiao Niu,Houde She,Yingpu Bi,Ziqiang Lei
The leaf-like structure BiVO 4 electrode and MFe 2 O 4 /BiVO 4 (M = Ni, Co) composite photoelectrodes were prepared by electrochemical deposition, ensuing heating treatment and electrophoretic deposition technology. The characterizations of SEM, XRD and DRS indicated that the BiVO 4 derivatives mainly existed in small nanoparticles with monoclinic phase and exhibited stronger light absorption capability than that of pure BiVO 4 . Hereon, the respective photoelectrochemical (PEC) activities of BiVO 4 and its derived composites were systematically studied. The results suggested that the NiFe 2 O 4 /BiVO 4 and CoFe 2 O 4 /BiVO 4 not only showed higher photocurrent response values at 1.23 V vs. NHE than pure BiVO 4 electrode under visible light illumination, but also played a superior PEC hydrogen evolution performance, which was considered owing to their strong absorption to light, reduction combination of carriers and effective separation of electrons and holes.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Yingjie Chen,Shiben Liu,Liyan Yu,Qiuhong Liu,Yongtao Wang,Lifeng Dong
Nanoparticles with core–shell or hollow interiors have immense potential for catalysis. Herein, Ag@M x Fe 3− x O 4 (M = Co, Mn) core–shell nanoparticles were firstly synthesized through a seed-mediated method. These particles were then loaded onto carbon catalyst supports to form Ag@M x Fe 3− x O 4 /C. Then, hollow-M x Fe 3− x O 4 /C was prepared with the diffusion of Ag from Ag@M x Fe 3− x O 4 /C in saturated NaCl solution at room temperature . As a result, Ag@MnFe 2 O 4 /C demonstrates better oxygen reduction reaction (ORR) activity than Ag@CoFe 2 O 4 /C and other Ag@Mn x Fe 3− x O 4 /C with various Mn/Fe ratios. Moreover, Ag@MFe 2 O 4 /C shows superior ORR catalytic activities over hollow-MFe 2 O 4 /C, which can be due to electronic coupling between Ag core and MFe 2 O 4 shell. Furthermore, Ag@MnFe 2 O 4 /C catalysts demonstrate high durability for the ORR in alkaline media and insensitivity to methanol. These findings will provide helpful guidance for design and fabrication of carbon-supported core–shell catalysts for ORR in the future.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2018
·
IF 2.21
Zhixiang Jiang,Yue Zhao,Ping Yang
Wire-in-tube and tube-in-tube structures have been prepared using single-spinneret electrospinning method through adjusting the preparation parameters of precursors and subsequent calcined process. Cobalt ferrite (CoFe 2 O 4 ) samples revealed wire-in-tube morphology using a Co/Fe molar ratio of 1/2. In the case of other a Co/Fe molar ratio, belt and porous fiber morphologies were created. Manganese ferrite (MnFe 2 O 4 ) sample exhibited tube-in-tube structure while nickel ferrite (NiFe 2 O 4 ) sample just exhibited tube structure. Because of no template in electrospun polymer composite nanofibers , the precursor diffusion process during calcination plays an important role for morphology controlling. The magnetic properties of samples were examined. The cobalt ferrite (CoFe 2 O 4 ) wire-in-tube sample revealed the highest saturation magnetization (60 emu/g). After growing with AlOOH on the surface, CoFe 2 O 4 wire-in-tube sample revealed a high efficiency for the removal of Congo red pollutant. These nanostructures are particularly attractive for use in the field of nano-fluidic and nano-energy harvesting devices.
研究领域:
材料科学
·
环境科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Superconductivity and Novel Magnetism
·
2023
·Vol. 36
·期 2
·711-719
·
IF 1.8
Huang Danqiang,Wen Xinchao,Dai Jianfeng,Wang Qing,Liu Hui,Li Zengpeng
In this study, SrFe 12 O 19 @MFe 2 O 4 (M = Co, Ni, Zn) core–shell nanofibers were fabricated by coaxial electrostatic spinning. The composites obtained at an annealing temperature of 900 °C are composed of SrFe 12 O 19 in pure phase and MFe 2 O 4 (M = Co, Ni, Zn) in different spinels. X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and transmission electron microscope (TEM) were used to describe the structure and morphology of nanofibers. Magnetic Property Measurement Systems (MPMS) are used to characterize the magnetic properties of nanofibers. Sr@Ni and Sr@Zn fibers all exhibit a unique core–shell structure, while Sr@Co fibers are connected by a lamellar structure. The single-phase hysteresis lines for each composite indicate the presence of exchange coupling effects between the hard/soft magnetic composite phases. The magnetic properties of the composites change as the soft magnetic material in the shell layer changes. Sr@Co has the highest M s (69.43 emu/g) and M r (33.82 emu/g), whereas Sr@Zn has the highest H c (2927 Oe). The switching plant curves indicate that the best exchange coupling of the three groups of samples is for Sr@Co. The magnetic properties of the composites are explained in terms of the nanofiber diameter, the exchange coupling between the two phases, and the nature of the soft magnetic phase itself. It is shown that the exchange coupling of composites is closely related to the type of composite.
研究领域:
材料科学
·
磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Li Lv,Yinglin Wang,Pengfei Cheng,Yue Zhang,Yaoqiong Zhang,Zhaohui Lei,Luping Xu,Zhi Weng
In this study, a one-step chemical vapor deposition (CVD) method was used, utilizing template NaCl and dextrin as the porogen and structural support. The synthesized spinel MFe 2 O 4 (M = Zn, Ni, Cu, Co and Mn) microspheres with multiple cavities structure were applied to the acetone gas sensor detection. Through the characterization of the sensitive materials, the average pore diameter of the microspheres was about 60 nm. Compare with other metal cations , when M = Zn or Ni, the MFe 2 O 4 samples revealed the super gas sensitivity at working temperatures of 250 °C and 175 °C, and the response values to 100 ppm acetone were 25 and 24.3, respectively. In addition, they also exhibited excellent selectivity and long-term stability to acetone. The excellent gas sensitivity of ZnFe 2 O 4 and NiFe 2 O 4 could be attributed to the replacement of Fe with Zn and Ni ions to obtain a higher Fe 3+ /Fe 2+ atomic ratio, thereby increasing the content of adsorbed oxygen. In summary, the gas sensing performance of spinel MFe 2 O 4 oxide had been systematically studied by replacing Fe with other transition metals. The iron-containing spinel oxides are expected to be promising sensing material for gas sensors due to their rich elements and excellent activity.
研究领域:
材料科学
·
传感器技术
✓ 已验证
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2023
·
IF 6.1
Hao Cai,Tianci Zhao,Zichuan Ma
Nanoscale magnetic spinel ferrite composites with the general formula MFe 2 O 4 @PC (M = Fe, Cu, Co, and Mn; PC = biochar) were prepared by a facile impregnation and pretreatment method. MFe 2 O 4 @PC particles were deliberated by X-ray Diffractometer (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), Brunauer–Emmett–Teller adsorption–desorption isotherm (BET), X-ray Photoelectron Spectroscopy (XPS) and Vibrating Sample Magnetometer. The results showed that MFe 2 O 4 coating, which is evenly distributed on the surface of HNO 3 -pretreated biochar, can provide more active sites to enable MFe 2 O 4 @PC to be activated by visible light. The XRD confirmed that the crystallite sizes of MFe 2 O 4 ranged from 10.0 to 27.9 nm. With the help of surface-OH, PCoF has a rapid adsorption performance on metronidazole (MNZ) and can degrade 99% of MNZ within 20 minutes at an optimal pH of 3.0. Meanwhile, the PCuF composites showed excellent photo-Fenton catalytic performance for the degradation of MNZ under neutral pH conditions, and 96.0% of MNZ (300 mg/L) could be removed within 120 min. This study confirmed OH is the main reactant, while O 2 − and h + contributed to the degradation of MNZ during photocatalysis . MFe 2 O 4 @PC composite can be separated easily by an external magnetic field. The synthesized PCoF was reused for 5 cycles and it was clear that it had no significant loss, indicating its excellent ability to remove MNZ from wastewater.
研究领域:
环境科学
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材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 45
·23641-23650
·
IF 8.867
Zhong-Jie Jiang,Si Cheng,Haibo Rong,Zhongqing Jiang,Jianlin Huang
A general method has been developed for the synthesis of the spindle-like MFe2O4/C (M = Zn, Co, Ni, Mn). The synthetic procedure involves the preparation of mixed metal organic frameworks (i.e. Fe2M-MOFs) and their subsequent calcination. The obtained MFe2O4/C spindles show an intriguing structure, which consists of carbon coated secondary MFe2O4 nanoparticles with an interconnected carbon network. This makes them highly promising as the active materials for various applications with enhanced performance. For example, when used as the anode for lithium ion batteries (LIBs), the MFe2O4/C spindles exhibit higher reversible capacities and higher cycling stability in comparison to the MFe2O4 materials reported previously. Most interestingly, these MFe2O4/C spindles exhibit good morphology preservation during cycling. This shows that the volumetric expansion of MFe2O4 upon lithiation leads to the leaching of some active materials to the surface of the MFe2O4/C spindles along the percolation channels. This alleviates the volumetric expansion energy and prevents the structural destruction of MFe2O4/C spindles. The leached active materials do not detach from the MFe2O4/C spindles and participate in the lithiation/delithiation reactions throughout the whole cycling process, giving the MFe2O4/C spindles with high specific capacity and good durability. The approach reported here is highly versatile and might be applicable to the synthesis of other MFe2O4/C spindles for various applications.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2019
·
IF 3.89
Wenning Yang,Jia Li,Min Liu,Dickon H.L. Ng,Yong Liu,Xiaofan Sun,Jie Yang
Novel hierarchically porous CoAl-LDH (layered double hydroxides)/MFe 2 O 4 (Ni, Zn, Co) hybrids with excellent peroxidase-like catalytic activity , high selectivity and reusability were first fabricated by using natural cotton as a bio-template. Among them, CoAl-LDH/NiFe 2 O 4 exhibited the best intrinsic peroxidase-like property due to its 3D hierarchically porous structure with more exposed active sites, which could effectively catalyze peroxidase substrate 3,3′,5,5′- tetramethylbenzidine (TMB) in the presence of H 2 O 2 to produce typical blue color reaction. A facile and visual system for glucose detection using glucose oxidase was successfully established, which exhibited a sensitive response to glucose in the range of 25–400 μM with detection limit of 13 μM based on the hydroxyl radical originated from the decomposition of H 2 O 2 by the catalysis of CoAl-LDH/MFe 2 O 4 (Ni, Co, Zn) hybrids. This work offered an effective strategy to achieve morphology-controllable hierarchically porous materials and provided a new insight into seeking novel enzyme mimetics with enhanced catalytic activities.
研究领域:
材料科学
·
分析化学
·
生物传感器
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2023
·
IF 6.2
A.V. Ravindra,M. Chandrika,Andem Sandeep
This work presents the effectual degradation of MB and MO dyes in an aqueous solution under UV light irradiation on nano ZnFe 2 O 4 , NiFe 2 O 4 , and Fe 3 O 4 without using any supplementary oxidants has been reported. Nano ZnFe 2 O 4 , NiFe 2 O 4 , and Fe 3 O 4 are successfully prepared via a co-precipitation technique utilizing biodegradable starch as a surfactant . XRD patterns reveal a pure spinel phase for all the samples. FTIR spectra confirm the successful embedding of the starch surfactant. SEM micrographs exhibit tiny spherical particles of size 5–8 and 4–6 nm for ZnFe 2 O 4 and NiFe 2 O 4 but spherical particles of 8–10 nm and flake-like particles of ∼14 nm thick for Fe 3 O 4 . N 2 sorption studies show type-IV isotherms typical of mesoporous structures. The direct bandgap of these ferrite nanoparticles is 2.03–2.15 eV, related to the metal D-d onsite transfers, which are permitted by spin but prohibited by parity. MB decolorization of 99% is achieved in less than 2 h for all the samples; in contrast, MO decolorization takes relatively longer irradiation. The decolorization kinetics suggests that the pseudo-second-order model is more appropriate to explain the decolorization process of MB and MO by the catalysts. The order of photocatalytic activity evaluated from rate constant (k 1 ) per SSA values is Fe 3 O 4 < ZnFe 2 O 4 < NiFe 2 O 4 for both MB and MO decolorization. NiFe 2 O 4 photocatalyst shows the best effect on the decolorization of both dyes due to its low bandgap and high surface area. All the ferrite catalysts demonstrate high stability with no substantial deterioration of photocatalytic activity even after three cycles. The results of this study endorse that the nano ferrites prepared in this work are potential candidates for the photocatalytic degradation of aqueous solutions of MB and MO.
研究领域:
环境科学
·
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Russian Journal of Physical Chemistry A
·
2022
·Vol. 96
·期 8
·1761-1767
·
IF 0.791
Chen Yu,Liu Miao
Abstract A modified polyacrylamide gel route with urea used as fuel was used to synthesize the MFe 2 O 4 (M = Mg, Ca, Ba) iron oxides with high adsorption capacity for removal of Cd(II) from water treatment. The phase structure, functional group, porous structure and adsorption performance of MFe 2 O 4 (M = Mg, Ca, Ba) iron oxides were characterized by X-ray-diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), N 2 adsorption–desorption isotherm and 721 spectrophotometer. The result indicates that the phase forming temperature of MFe 2 O 4 , the content of carbonate ion in MFe 2 O 4 increases with the increasing of the radius of M-site metal ion. The E g value, BET surface area and adsorption capacity for removal of Cd(II) from water treatment decreases with the increasing of the radius of M-site metal ion. The experimental isotherm of MFe 2 O 4 (M = Mg, Ca, Ba) iron oxides were described by the Langmuir model. MgFe 2 O 4 iron oxide exhibits a best adsorption performance for removal of Cd(II) from water treatment by the adsorption process, with a maximum adsorption capacity of ca. 221.36 mg/g than that of other iron oxides. The present synthetic route could be possibly extended to synthesize other porous metal oxide materials with special porous structures for various applications.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2015
·
IF 3.453
M. Penchal Reddy,A.M.A. Mohamed
A series of metal ferrite mesoporous MFe 2 O 4 (M = Mn, Co, and Ni) nanospheres with an average diameter of about 100–300 nm were synthesized through a one-pot template-free solvothermal method in ethylene glycol (EG) solution. The effect of reaction parameters on products was characterized in detail by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, physical property measurement system, X-ray photoelectron spectroscopy and volumetric nitrogen adsorption. The XRD patterns indicate that all the samples were formed in single phase spinel structure. By changing Co 2+ to different cations, MnFe 2 O 4 , NiFe 2 O 4 , and ZnFe 2 O 4 with different magnetic properties could be obtained. The mesoporous MnFe 2 O 4 with a large surface area of 140.8 m 2 /g and an average pore size of 12.6 nm were obtained. Furthermore, magnetic properties of M-ferrite nanospheres could be tuned by changing substituted metal cations. The possible growth mechanism of mesoporous nanospheres was discussed on the basis of the investigation of reaction parameters.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2017
·Vol. 164
·期 13
·F1483
·
IF 3.259
Yingjie Chen,Shiben Liu,Zhihao Shi,Jianhua Yu,Hongzhou Dong,Yong Qin,Liyan Yu,Lifeng Dong
Ag-MFe2O4 (M = Co, Mn) nanocomposites were synthesized and loaded onto carbon supports. As-prepared Ag-MFe2O4/C demonstrated higher catalytic activity for oxygen reduction reaction (ORR) than Ag+MFe2O4/C. The direct coupling and electron transfer between Ag and MFe2O4 in nanocomposites were proposed to enhance their catalytic activities. The Koutecky-Levich plots confirmed a direct four-electron reaction pathway for the ORR on Ag-MFe2O4/C. Furthermore, Ag-MFe2O4/C showed superior catalytic activities and excellent stability for oxygen evolution reaction (OER). Thus, Ag-MFe2O4/C nanoparticle are potential non-Pt candidates with bi-functional catalytic activity for ORR and OER.
研究领域:
材料科学
·
电化学
✓ 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）