A novel and efficient route for preparing carbon encapsulated metal nanomaterials using staple biopolymer-starch as the carbon precursor was presented. Fe particles can be effectively encapsulated inside carbon shells...A novel and efficient route for preparing carbon encapsulated metal nanomaterials using staple biopolymer-starch as the carbon precursor was presented. Fe particles can be effectively encapsulated inside carbon shells by carbonizing composite of starch and iron oxide under hydrogen in a controllable way. Transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) were employed to characterize carbon encapsulated nanomaterials. The α-Fe and γ-Fe phases were clearly identified in those carbon encapsulated nanoparticles. The growth mechanism of carbon encapsulated metal nanoparticles was briefly discussed.展开更多
Carbon encapsulated iron nanoparticles （CEINPs） with very thin shells and good core-shell structures were prepared by DC arc discharge at argon intake temperature （AIT） of 800 ℃. The results of high resolution tr...Carbon encapsulated iron nanoparticles （CEINPs） with very thin shells and good core-shell structures were prepared by DC arc discharge at argon intake temperature （AIT） of 800 ℃. The results of high resolution transmission electron microscope （HRTEM）, energy dispersive X-ray （EDX） spectroscope, X-ray diffraction （XRD）, and X-ray photoelectron spectroscope （XPS） characterizations on the product B show that the thickness of the carbon shells of CEINPs in the product B is in the range of ca. 0.5-5.3 nm, i. e., which can be as thin as only two layers of graphite. The average diameter of the CEINPs is about 24. 7 nm. The total content of Fe element in the product B is 77.0 wt%. The saturation magnetization （Ms） and coercivity （Hc） of the product B are 107.4 emu/g and 143 Oe. resnectivelv. The formation of the CEINPs in the oroduct B is discussed briefly.展开更多
Carbon encapsulated magnetic nanoparticles （CEMNs） were synthesized by heating an aqueous glucose solution containing Fe-Au （Au coated Fe nanoparticles） nanoparticles at 160-180 ℃ for 2 h. This novel hydrothermal...Carbon encapsulated magnetic nanoparticles （CEMNs） were synthesized by heating an aqueous glucose solution containing Fe-Au （Au coated Fe nanoparticles） nanoparticles at 160-180 ℃ for 2 h. This novel hydrothermal approach is not only simple but also provides the surface of CEMNs with functional groups like--OH. The formation of carbon encapsulated magnetic nanoparticles was not favored when using pure Fe nanoparticles as cores because of the oxidation of Fe nanoparticles by 1-120 during the reaction and, therefore, the surfaces of the naked Fe nanoparticles had to be coated by Au shell in advance. TEM, XRD, XPS and VSM measurments characterized that they were uniform carbon spheres containing some embedded Fe-Au nanoparticles, with a saturation of 14.6 emu/g and the size of the typical product is -350 nm.展开更多
基金the National Natural Science Foundation of China (20174017)
文摘A novel and efficient route for preparing carbon encapsulated metal nanomaterials using staple biopolymer-starch as the carbon precursor was presented. Fe particles can be effectively encapsulated inside carbon shells by carbonizing composite of starch and iron oxide under hydrogen in a controllable way. Transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) were employed to characterize carbon encapsulated nanomaterials. The α-Fe and γ-Fe phases were clearly identified in those carbon encapsulated nanoparticles. The growth mechanism of carbon encapsulated metal nanoparticles was briefly discussed.
文摘Carbon encapsulated iron nanoparticles （CEINPs） with very thin shells and good core-shell structures were prepared by DC arc discharge at argon intake temperature （AIT） of 800 ℃. The results of high resolution transmission electron microscope （HRTEM）, energy dispersive X-ray （EDX） spectroscope, X-ray diffraction （XRD）, and X-ray photoelectron spectroscope （XPS） characterizations on the product B show that the thickness of the carbon shells of CEINPs in the product B is in the range of ca. 0.5-5.3 nm, i. e., which can be as thin as only two layers of graphite. The average diameter of the CEINPs is about 24. 7 nm. The total content of Fe element in the product B is 77.0 wt%. The saturation magnetization （Ms） and coercivity （Hc） of the product B are 107.4 emu/g and 143 Oe. resnectivelv. The formation of the CEINPs in the oroduct B is discussed briefly.
文摘Carbon encapsulated magnetic nanoparticles （CEMNs） were synthesized by heating an aqueous glucose solution containing Fe-Au （Au coated Fe nanoparticles） nanoparticles at 160-180 ℃ for 2 h. This novel hydrothermal approach is not only simple but also provides the surface of CEMNs with functional groups like--OH. The formation of carbon encapsulated magnetic nanoparticles was not favored when using pure Fe nanoparticles as cores because of the oxidation of Fe nanoparticles by 1-120 during the reaction and, therefore, the surfaces of the naked Fe nanoparticles had to be coated by Au shell in advance. TEM, XRD, XPS and VSM measurments characterized that they were uniform carbon spheres containing some embedded Fe-Au nanoparticles, with a saturation of 14.6 emu/g and the size of the typical product is -350 nm.
