ACS Applied Nano Materials
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2018
·
IF 0
Wuzhu Sun,Weiyi Yang,Zhengchao Xu,Qi Li
A novel and environmentally benign approach was developed to create a Fe3O4@SiO2 core–shell structure supported Pd catalyst consisting of a superparamagnetic Fe3O4 nanosphere core, a SiO2 shell with a rough surface, Pd nanoparticles deposited on a SiO2 shell, and a cross-linked polyvinylpyrrolidone (PVP) layer. It was found that both adsorbed PVP and SiO2 shell with a rough surface from the surface-protected etching process were critical to obtain the uniform PdO deposition, while the cross-linked PVP layer could effectively anchor and protect active Pd nanoparticles to enhance their stability to resist detachment from the catalyst support and improve the reusability of the catalyst. Because of its superparamagnetic behavior, it could disperse well in aqueous solution without external magnetic field and be separated easily from aqueous solution when an external magnetic field was present. It demonstrated a high catalytic activity, desirable N2 product selectivity over 99.7%, and good reusability for the catalytic nitrite reduction in aqueous solution.
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Journal of Applied Spectroscopy
·
2018
·Vol. 85
·期 1
·160-165
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IF 0.611
Neng Jing,Wang Xujun,Jia Kan,Sun Peilong
Fe 3 O 4 nanoparticles were first modified with tetraethoxylsilane to form Fe 3 O 4 /SiO 2 nanoparticles, followed by the addition of 3-aminopropyltriethoxysilane and 3-thiolpropyltriethoxysilane to introduce –NH 2 and –SH groups to the surface of Fe 3 O 4 /SiO 2 nanoparticles. Gold nanoparticles were further assembled on the surface of Fe 3 O 4 /SiO 2 via the electrostatic adsorption of –NH 2 and the Au–S bond to produce stable core–shell Fe 3 O 4 /SiO 2 /Au gold/magnetic nanoparticles. These Fe 3 O 4 /SiO 2 /Au gold/magnetic nanoparticles were characterized by a variety of techniques such as transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX), and afterwards conjugated with tetrodotoxin antibodies (Ab) and used as a Raman active substrate (Fe 3 O 4 /SiO 2 /Au–Ab) with Rhodamine B (RhB)-labeled tetrodotoxin antibody as a Raman reporter (Ab–RhB). Upon mixing these reagents with tetrodotoxin (TTX), a sandwich complex [Fe 3 O 4 /SiO 2 /Au–Ab···TTX···Ab–RhB] was generated due to the specific antibody–antigen interactions. The immunocomplex was subsequently separated by an externally applied magnetic source and concentrated into a pellet point, where the laser interrogation of the pellet produced a strong signal characteristic of RhB. The logarithmic intensity of the signal was found to be proportional to the concentration of TTX with a limit of detection of 0.01 μg/mL and a detection linearity range of ~ 0.01–0.5 μg/mL. The established method eliminates the complicated procedures of traditional centrifuging, column separation, and incubation and achieves a rapid detection of tetrodotoxin with improved detection sensitivity.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2013
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IF 3.473
Baocun Zhu,Jie Zhao,Haiqin Yu,Liangguo Yan,Qin Wei,Bin Du
A novel 1,8-naphthalimide-functionalized Fe 3 O 4 @SiO 2 core/shell magnetic fluorescent nanoparticles ( MFNPs ) for simultaneous detection and adsorption of Hg 2+ was designed and synthesized. A series of adsorption studies were carried out with various Hg 2+ concentrations, temperature, time and pH. The maximum adsorption capacity is higher than 30 mg/g over a broad temperature (0 °C, 25 °C, and 50 °C) and pH (4–10). The results showed that MFNPs possesses an excellent reusability and the high adsorption specificity toward Hg 2+ . The detection limit for Hg 2+ is 3.4 nM. In addition, owing to the aggregation of MFNPs occurring in the Hg 2+ aqueous solution, the adsorbent was separated easily by the settlement or the external magnetic field, which facilitated the removal of Hg 2+ .
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2012
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IF 4.173
Zhuqing Wang,Dayu Wu,Genhua Wu,Ningning Yang,Aiguo Wu
Rhodamine hydrazide modifying Fe 3 O 4 microspheres (Fe 3 O 4 -R6G) was developed for selective detection and removal of mercury ion from water. With a saturation magnetization of 74.2 emu/g, the Fe 3 O 4 -R6G could be simply recollected from water with magnetic separation within a few minutes. The selectivity and adsorption ability of Fe 3 O 4 -R6G for metal cations were studied by fluorophotometry and atomic absorption spectrometry, respectively. The results showed that Fe 3 O 4 -R6G exhibited excellent selectivity for sensing mercury ion over other metal ions in aqueous solution, and also adsorbed 91% of mercury ion. The maximum adsorption capacity of the Fe 3 O 4 -R6G for Hg 2+ ion was 37.4 μmol g −1 . The Fe 3 O 4 -R6G was successfully applied to the determination of Hg 2+ in environmental samples, and could be used repeatedly by treatment with tetrabutylammonium hydroxide.
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PubMed
高影响因子
RSC Advances
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2015
·Vol. 5
·期 50
·39964-39972
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IF 3.84
Fubo Gu,Man Liang,Dongmei Han,Zhihua Wang
Two multifunctional sandwich-like mesoporous silica–graphene oxide (GO@mSiO2) and mesoporous silica–Fe3O4–graphene oxide (Fe3O4/GO@mSiO2) adsorbents were synthesized, and the adsorption equilibrium and kinetics of methylene blue on both of them were investigated. The structural and physical properties of the adsorbents were investigated by transmission electron microscopy, X-ray diffraction, vibrating magnetometry, nitrogen adsorption–desorption measurement and their chemical properties were analyzed by X-ray photoelectron spectroscopy, infrared spectroscopy, and Raman spectroscopy. GO@mSiO2 exhibited a high specific surface area of 634 m2 g−1 and its maximum adsorption capacity for methylene blue was 305.3 mg g−1. The specific surface and the maximum adsorption capacity were 179 m2 g−1 and 125.1 mg g−1 to Fe3O4/GO@mSiO2, which could be recycled by using an external magnetic field because of its magnetic property. Moreover, both adsorbents exhibited photothermal properties. A second-order kinetic equation could best describe the adsorption kinetics. Thermodynamic parameters indicated that the adsorption of methylene blue onto both adsorbents was thermodynamically feasible and could occur spontaneously.
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高影响因子
RSC Advances
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2015
·Vol. 5
·期 126
·103943-103955
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IF 3.84
Yongbo Shao,Tao Jing,Jingzhi Tian,Yongjie Zheng
Nano- and hybrid materials have recently emerged as a new approach for improving enzyme activity and stability, and are suitable for commercial applications. In this paper, graphene oxide-based magnetic hybrids were prepared successfully. A chloropropyl-functionalized graphene oxide decorated with Fe3O4 nanoparticles was made, denoted as CPS/GO-Fe3O4@MCM-41. This was characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometry, thermogravimetry and N2 adsorption/desorption. Then, porcine pancreas lipase (PPL) was immobilized onto the graphene oxide-based magnetic nanoparticles via covalent bonding. The results show that the novel supporting material CPS/GO-Fe3O4@MCM-41 was the best for PPL immobilization compared to two other nanomaterials (GO-Fe3O4@MCM-41 and GO-Fe3O4). The supporting material CPS/GO-Fe3O4@MCM-41 exhibited enhanced immobilization efficiency (up to 98%), maximum relative activity (up to 97.9%), high stability and reusability (85% after 56 d and 87% after 10 cycles respectively, both at 30 °C). Additionally, it offered some other advantages, such as easy recycling and reuse, complying with the requirements of green chemistry. Therefore, it is proposed that CPS/GO-Fe3O4@MCM-41 provides a new approach for commercial applications.
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高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
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2015
·
IF 1.97
Liuhua Yu,Gazi Hao,Junjun Gu,Shuai Zhou,Ning Zhang,Wei Jiang
In this work, Fe 3 O 4 /PS composites with a rough surface and different coating rates were successfully designed and synthesized by emulsion polymerization. We carried out some comparative experiments to compare magnetic properties and oil absorption properties of the nano-magnetic materials. It had been found that several prepared groups of magnetic nanocomposites have a core–shell structure and good coating rates. These nanoparticles combined with unsinked, highly hydrophobic and superoleophilic properties. The absorption capacity of Fe 3 O 4 /PS composites for organic solvents and the composites could absorb diesel oil up to 2.492 times of its own weight. It is more important that the oil could be readily removed from the surfaces of nanoparticles by a simple ultrasonic treatment whereas the nanocomposites particles still kept highly hydrophobic and superoleophilic characteristics. With a combination of simple synthesis process, low density, magnetic responsibility and excellent hydrophobicity , Fe 3 O 4 /PS nanocomposites as a promising absorbent have great potential in the application of spilled oil recovery and environmental protection.
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高影响因子
RSC Advances
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2015
·Vol. 5
·期 70
·56478-56485
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IF 3.84
Guozhi Fan,Shanshan Luo,Qiang Wu,Tao Fang,Jianfen Li,Guangsen Song
A magnetic Fe3O4@SiO2–ZnBr2 catalyst was prepared by supporting ZnBr2 on silica-coated magnetic nanoparticles of Fe3O4 and used as a recoverable catalyst for the direct synthesis of diphenyl carbonate (DPC) from CO2 and phenol in the presence of carbon tetrachloride. The as-prepared catalyst was characterized by infrared spectroscopy (IR), powder X-ray diffraction (XRD), a X-ray photoelectron spectrometer (XPS) and BET. Zn loading in the supported catalyst and leaching during the reaction process were determined by atomic absorption spectroscopy (AAS). It was found that Fe3O4@SiO2–ZnBr2 showed higher catalytic activity than homogenous ZnCl2 and ZnI2 as well as homogenous ZnBr2. With this new catalyst under optimized conditions, a yield of DPC at 28.1% was obtained. The heterogeneous catalyst Fe3O4@SiO2–ZnBr2 can also be recovered by a permanent magnet after the reaction and reused up to 4 times without noticeable deactivation.
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高影响因子
MEASUREMENT
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2014
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IF 1.526
Yixin Liu,Wenjuan Zhu,Dan Wu,Qin Wei
Amino-group functionalized mesoporous Fe 3 O 4 nanoparticles were prepared by a simple solvothermal method. Palladium (Pd)-loaded amino-group functionalized mesoporous Fe 3 O 4 nanoparticles (Pd@Fe 3 O 4 ) were prepared with ethanol as the reductant. Pd@Fe 3 O 4 modified the glassy carbon electrode (GCE) exhibited excellent electrochemical catalytic activities towards dopamine (DA) due to the synergetic effect between Pd and Fe 3 O 4 . Electrochemical behavior of Pd@Fe 3 O 4 /GCE towards DA was studied using square wave voltammetry and the selective determination of DA was carried out successfully at high concentration of uric acid. A wide concentration range (0.96–107 μmol/L) and low detection limit (0.41 μmol/L, S/N = 3) for the determination of DA were obtained. The advantageous properties of this electrode for the DA determination lie in its excellent catalytic activity, selectivity and simplicity. The prepared sensor had been applied to the analysis of DA in human serum samples with satisfactory results.
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高影响因子
CATALYSIS COMMUNICATIONS
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2014
·
IF 3.32
Xuanduong Le,Zhengping Dong,Zhicheng Jin,Qingqing Wang,Jiantai Ma
In this study, a novel Pd(II) complex functionalized core–shell magnetic mesoporous catalyst (Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II)) was synthesized by a simple cost effective procedure. It was characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, vibrating sample magnetometer, and nitrogen physical adsorption. The Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II) catalyst offered high surface area and exhibited excellent activity towards Suzuki–Miyaura cross-coupling reaction of halides with aryl boronic acids in ethanol in air. The Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II) catalyst was stable, reusable, and conveniently recovered by applying an external magnetic field. Moreover, it provided 91% conversion after the sixth catalytic run. The Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II) catalyst examined in this study combined both the efficiency of a homogeneous catalyst and the durability of a heterogeneous catalyst. The results revealed that the Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II) catalyst is promising as a candidate for various Pd-based catalytic applications.
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高影响因子
CARBON
·
2015
·
IF 6.196
Xiangcun Li,Le Zhang,Gaohong He
Double-shelled hollow carbon spheres with multiporosity, highly conductive graphite structure and Fe 3 O 4 species was initially prepared (C–C–Fe 3 O 4 ). The seamless combination between the Fe 3 O 4 species and the porous carbon network leads to a remarkably high capacitivity (1153 F g −1 at 2 A g −1 ) and good rate capability (514 F g −1 at 100 A g −1 ) of pseudocapacitive. In addition, the C–C–Fe 3 O 4 assembled asymmetric supercapacitor demonstrates excellent cycling stability (96.7% retention of the initial capacitance after 8000 cycles) and achieves high energy density (17–45 W h kg −1 ) at powder density of 400–8000 W kg −1 . The unique porous carbon structure and seamlessly integration between carbon and Fe 3 O 4 species generate synergistic effect to boost high performance and ideal durability, and high conductivity of the graphitized carbon, the large specific surface area of the hierarchical pore network and the perfectly distributed Fe 3 O 4 redox species in the carbon content also account for its ideal capacitive properties. The multiporous structure could allow efficient diffusion of electrolyte and promote interfacial redox reactions of supercapacitor by facilitating the accessibility of redox active sites, and the highly uniform distribution of Fe 3 O 4 species in the porous carbon makes the best use of conductive carbon network and facilitates good rate capability.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2017
·
IF 2.843
Meijuan Wang,Wenjun Yan,Wei Kong,Zhijun Wu,Xiaowei An,Zhongde Wang,Xiaogang Hao,Guoqing Guan
An electrochemically regenerable Fe3O4@polypyrrole (PPy) core–shell nanocomposite with superparamagnetism for selective fluoride ion removal from wastewater is fabricated. The rapid fluoride ion uptake kinetics is realized in a batch experiment due to the good affinity of PPy toward fluoride ions. It is found that the pseudo-second-order model can well describe the adsorption kinetics and the equilibrium data fits well with the Freundlich isotherm model. The spontaneity and exothermic nature of the fluoride ion adsorption are confirmed based on thermodynamic parameter analysis. In an electromagnetic coupling system, the nanocomposites exhibit a high regeneration efficiency around 95% in each cycle and only a slight drop in the capacity retention rate of fluoride ion adsorption even after 20 adsorption–regeneration cycles. This intelligently magnetic nanocomposite should be a promising alternative material for fluoride ion removal from wastewater.
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高影响因子
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