Two important iron oxides： Fe304 and Fe203, as well as Fe304 and Fe203 nanoparticles mingling with Ag were successfully synthesized via a hydrothermal procedure. The samples were confirmed and characterized by X-ray ...Two important iron oxides： Fe304 and Fe203, as well as Fe304 and Fe203 nanoparticles mingling with Ag were successfully synthesized via a hydrothermal procedure. The samples were confirmed and characterized by X-ray diffraction （XRD）, and X-ray photoelectron spectroscopy （XPS）. The morphology of the samples was observed by transmission electron microscopy （TEM）. The results indicated Fe304, Fe203, Ag/Fe304 and Ag/Fe203 samples all were nanoparticles with smaller sizes. The samples were modified on a glassy carbon electrode and their elctrocatalytic properties for p-nitropbenol in a basic solution were investigated. The results revealed all the samples showed enhanced catalytic performances by comparison with a bare glassy carbon electrode. Furthermore, p-nitrophenol could be reduced at a lower peak potential or a higher peak current on a glassy carbon electrode modified with Ag/Fe304 or Ag/Fe203 composite nanoparticles.展开更多
Some factors effected on heterogeneous hydrothermal stripping from iron-loaded organic phase of naphthenic acid-isooctyl alcohol-kerosene,such as the concentrations of initial iron and naphthenic acid,the weight of&qu...Some factors effected on heterogeneous hydrothermal stripping from iron-loaded organic phase of naphthenic acid-isooctyl alcohol-kerosene,such as the concentrations of initial iron and naphthenic acid,the weight of"seed"of Fe2O3,temperature and time,were investigated.The process rate equation and the relation between stripping percent and time needed were established.The results showed the proces activation energy was 114 kJ·mol-1 and the heterogeneous hydrothermal stripping was controlled by the hydrolysis of naphthenic compound of iron.展开更多
In this work, compressive, flexural and split tensile strength together with coefficient of water absorption of high performance self-compacting concrete containing different amount of Fe2Os nanoparticles have been in...In this work, compressive, flexural and split tensile strength together with coefficient of water absorption of high performance self-compacting concrete containing different amount of Fe2Os nanoparticles have been investigated. The strength and the water permeability of the specimens have been improved by adding Fe2Os nanoparticles in the cement paste up to 4.0 wt%. Fe203 nanoparticle as a foreign nucleation site could accelerate C-S-H gel formation as a result of increased crystalline Ca（OH）2 amount especially at the early age of hydration and hence increase the strength of the specimens. In addition, Fe203 nanoparticles are able to act as nanofillers and recover the pore structure of the specimens by decreasing harmful pores to improve the water permeability. Several empirical relations have been presented to predict the flexural and the split tensile strength of the specimens by means of the corresponding compressive strength at a certain age of curing. Accelerated peak appearance in conduction calorimetry tests, more weight loss in thermogravimetric analysis and more rapid appearance of peaks related to hydrated products in X-ray diffraction results indicate that Fe203 nanoparticles up to 4 wt% could improve the mechanical and the physical properties of the specimens.展开更多
Fe203 particle catalysts were experimentally studied in the low temperature selective catalytic reduction （SCR） of NO with NH3. The effects of reaction temperature, oxygen concentration, [NH3]/[NO] molar ratio and r...Fe203 particle catalysts were experimentally studied in the low temperature selective catalytic reduction （SCR） of NO with NH3. The effects of reaction temperature, oxygen concentration, [NH3]/[NO] molar ratio and residence time on SCR activity were studied. It was found that Fe203 catalysts had high activity for the SCR of NO with NH3 in a broad temperature range of 150-270℃, and more than 95% NO conversion was obtained at 180℃ when the molar ratio [NH3]/[NO] = 1, the residence time was 0.48 seconds and 02 volume fraction was 3%. In addition, the effect of SO2 on SCR catalytic activity was also investigated at the temperature of 180℃. The results showed that deactivation of the Fe2O3 particles occurred due to the presence of SO2 and the NO conversion decreased from 99.2% to 58% in 240 min, since SO2 gradually decreased the catalytic activity of the catalysts. In addition, X-ray diffraction, Thermogravimetric analysis and Fourier transform infrared spectroscopy were used to characterize the fresh and deactivated Fe2O3 catalysts. The results showed that the deactivation caused by SO2 was due to the formation of metal sulfates and ammonium sulfates on the catalyst surface during the de-NO reaction, which could cause pore plugging and result in suppression of the catalytic activity.展开更多
To improve the initial coulombic efficiency and bulk density of ordered mesoporous carbons, active Fe203 nanoparticles were introduced into tubular mesopore channels of CMK-5 carbon, which possesses high specific surf...To improve the initial coulombic efficiency and bulk density of ordered mesoporous carbons, active Fe203 nanoparticles were introduced into tubular mesopore channels of CMK-5 carbon, which possesses high specific surface area （〉1700 m2.g-1） and large pore volume （〉1.8 cm3-g-1）. Fine Fe203 nanoparticles with sizes in the range of 5-7 nm were highly and homogenously encapsulated into CMK-5 matrix through ammonia-treatment and subsequent pyrolysis method. The Fe203 loading was carefully tailored and designed to warrant a high Fe203 content and adequate buffer space for improving the electrochemical performance. In particular, such Fe203 and mesoporous carbon composite with 47 wt% loading exhibits a considerably stable cycle performance （683 mAh.g-1 after 100 cycles, 99% capacity retention against that of the second cycle） as well as good rate capability. The fabrication strategy can effectively solve the drawback of single material, and achieve a high-performance lithium electrode material.展开更多
Iron oxide nanoparticles are the most popular magnetic nanoparticles used in biomedical applications due to their low cost, low toxicity, and unique magnetic property. Magnetic iron oxide nanoparticles, including magn...Iron oxide nanoparticles are the most popular magnetic nanoparticles used in biomedical applications due to their low cost, low toxicity, and unique magnetic property. Magnetic iron oxide nanoparticles, including magnetite （Fe304） and maghemite （γ-Fe203）, usually exhibit a superparamagnetic property as their size goes smaller than 20 nm, which are often denoted as superparamagnetic iron oxide nanoparticles （SPIONs） and utilized for drug delivery, diagnosis, therapy, and etc. This review article gives a brief introduction on magnetic iron oxide nanoparticles in terms of their fundamentals of magnetism, magnetic resonance imaging （MRI）, and drug delivery, as well as the synthesis approaches, surface coating, and application examples from recent key literatures. Because the quality and surface chemistry play important roles in biomedical applications, our review focuses on the synthesis approaches and surface modifications of iron oxide nanopar- ticles. We aim to provide a detailed introduction to readers who are new to this field, helping them to choose suitable synthesis methods and to optimize the surface chemistry of iron oxide nanoparticles for their interests.展开更多
文摘Two important iron oxides： Fe304 and Fe203, as well as Fe304 and Fe203 nanoparticles mingling with Ag were successfully synthesized via a hydrothermal procedure. The samples were confirmed and characterized by X-ray diffraction （XRD）, and X-ray photoelectron spectroscopy （XPS）. The morphology of the samples was observed by transmission electron microscopy （TEM）. The results indicated Fe304, Fe203, Ag/Fe304 and Ag/Fe203 samples all were nanoparticles with smaller sizes. The samples were modified on a glassy carbon electrode and their elctrocatalytic properties for p-nitropbenol in a basic solution were investigated. The results revealed all the samples showed enhanced catalytic performances by comparison with a bare glassy carbon electrode. Furthermore, p-nitrophenol could be reduced at a lower peak potential or a higher peak current on a glassy carbon electrode modified with Ag/Fe304 or Ag/Fe203 composite nanoparticles.
文摘Some factors effected on heterogeneous hydrothermal stripping from iron-loaded organic phase of naphthenic acid-isooctyl alcohol-kerosene,such as the concentrations of initial iron and naphthenic acid,the weight of"seed"of Fe2O3,temperature and time,were investigated.The process rate equation and the relation between stripping percent and time needed were established.The results showed the proces activation energy was 114 kJ·mol-1 and the heterogeneous hydrothermal stripping was controlled by the hydrolysis of naphthenic compound of iron.
文摘In this work, compressive, flexural and split tensile strength together with coefficient of water absorption of high performance self-compacting concrete containing different amount of Fe2Os nanoparticles have been investigated. The strength and the water permeability of the specimens have been improved by adding Fe2Os nanoparticles in the cement paste up to 4.0 wt%. Fe203 nanoparticle as a foreign nucleation site could accelerate C-S-H gel formation as a result of increased crystalline Ca（OH）2 amount especially at the early age of hydration and hence increase the strength of the specimens. In addition, Fe203 nanoparticles are able to act as nanofillers and recover the pore structure of the specimens by decreasing harmful pores to improve the water permeability. Several empirical relations have been presented to predict the flexural and the split tensile strength of the specimens by means of the corresponding compressive strength at a certain age of curing. Accelerated peak appearance in conduction calorimetry tests, more weight loss in thermogravimetric analysis and more rapid appearance of peaks related to hydrated products in X-ray diffraction results indicate that Fe203 nanoparticles up to 4 wt% could improve the mechanical and the physical properties of the specimens.
基金supported by the National Natural Science Foundation of China(No.51276039)
文摘Fe203 particle catalysts were experimentally studied in the low temperature selective catalytic reduction （SCR） of NO with NH3. The effects of reaction temperature, oxygen concentration, [NH3]/[NO] molar ratio and residence time on SCR activity were studied. It was found that Fe203 catalysts had high activity for the SCR of NO with NH3 in a broad temperature range of 150-270℃, and more than 95% NO conversion was obtained at 180℃ when the molar ratio [NH3]/[NO] = 1, the residence time was 0.48 seconds and 02 volume fraction was 3%. In addition, the effect of SO2 on SCR catalytic activity was also investigated at the temperature of 180℃. The results showed that deactivation of the Fe2O3 particles occurred due to the presence of SO2 and the NO conversion decreased from 99.2% to 58% in 240 min, since SO2 gradually decreased the catalytic activity of the catalysts. In addition, X-ray diffraction, Thermogravimetric analysis and Fourier transform infrared spectroscopy were used to characterize the fresh and deactivated Fe2O3 catalysts. The results showed that the deactivation caused by SO2 was due to the formation of metal sulfates and ammonium sulfates on the catalyst surface during the de-NO reaction, which could cause pore plugging and result in suppression of the catalytic activity.
基金supported by the Fundamental Research Funds for the Central Universities (Grant No. DUT12ZD218)the National Natural Science Foundation of China (Grant No. 21103184)the Ph. D. Programs Foundation (Grant No. 20100041110017) of Ministry of Education of China
文摘To improve the initial coulombic efficiency and bulk density of ordered mesoporous carbons, active Fe203 nanoparticles were introduced into tubular mesopore channels of CMK-5 carbon, which possesses high specific surface area （〉1700 m2.g-1） and large pore volume （〉1.8 cm3-g-1）. Fine Fe203 nanoparticles with sizes in the range of 5-7 nm were highly and homogenously encapsulated into CMK-5 matrix through ammonia-treatment and subsequent pyrolysis method. The Fe203 loading was carefully tailored and designed to warrant a high Fe203 content and adequate buffer space for improving the electrochemical performance. In particular, such Fe203 and mesoporous carbon composite with 47 wt% loading exhibits a considerably stable cycle performance （683 mAh.g-1 after 100 cycles, 99% capacity retention against that of the second cycle） as well as good rate capability. The fabrication strategy can effectively solve the drawback of single material, and achieve a high-performance lithium electrode material.
基金Project supported by Start-up Grant of Nanyang Technological UniversityTier 1 Grant of Ministry of Education,Singapore(RGT8/13)
文摘Iron oxide nanoparticles are the most popular magnetic nanoparticles used in biomedical applications due to their low cost, low toxicity, and unique magnetic property. Magnetic iron oxide nanoparticles, including magnetite （Fe304） and maghemite （γ-Fe203）, usually exhibit a superparamagnetic property as their size goes smaller than 20 nm, which are often denoted as superparamagnetic iron oxide nanoparticles （SPIONs） and utilized for drug delivery, diagnosis, therapy, and etc. This review article gives a brief introduction on magnetic iron oxide nanoparticles in terms of their fundamentals of magnetism, magnetic resonance imaging （MRI）, and drug delivery, as well as the synthesis approaches, surface coating, and application examples from recent key literatures. Because the quality and surface chemistry play important roles in biomedical applications, our review focuses on the synthesis approaches and surface modifications of iron oxide nanopar- ticles. We aim to provide a detailed introduction to readers who are new to this field, helping them to choose suitable synthesis methods and to optimize the surface chemistry of iron oxide nanoparticles for their interests.
