We proposed a new way to synthesize a nanocomposite consisted of cementite Fe3C nanoparticles and amorphous carbon by radio frequency plasma-enhanced chemical vapor deposition. Transmission electron microscope images ...We proposed a new way to synthesize a nanocomposite consisted of cementite Fe3C nanoparticles and amorphous carbon by radio frequency plasma-enhanced chemical vapor deposition. Transmission electron microscope images show the existence of nanometric dark grains（Fe3C） embedded in a light matrix（amorphous carbon） in the samples. X-ray photoelectron spectroscopy experiment exhibit that the chemical bonding state in the films corresponded to sp3/sp2 amorphous carbon, sp^3 C-N（287.3 eV） and C15 in Fe3C（283.5 eV）. With increasing deposition time, the ratio of amorphous carbon increased. The magnetic measurements show that the value of in-lane coercivity increased with increasing carbon matrix concentration（from about 6.56× 10^3 A/m for film without carbon structures to approximately 2.77× 10^4 and 5.81 × 10^4 AJm for nanocomposite films at room temperature and 10 K, respectively）. The values of saturation magnetization for the synthesized nanocomposites were lower than that of the bulk Fe3C （ 140 Am^2/kg）.展开更多
Fe3C-functionalized three-dimensional （3D） porous nitrogen-doped graphite carbon composites （Fe3C/ NG） were synthesized via a facile solution-based impreg- nation and pyrolysis strategy using the commercially avai...Fe3C-functionalized three-dimensional （3D） porous nitrogen-doped graphite carbon composites （Fe3C/ NG） were synthesized via a facile solution-based impreg- nation and pyrolysis strategy using the commercially available melamine foam and FeC13 as precursors. The structural characterizations confirmed that Fe3C nanoparticles with an average core size about 122 nm were assembled on the surface of the carbonized melamine foam （CMF） skeletons. The electrochemical measurements demonstrated the superior electrocatalytic activity of the advanced Fe3C/NG composite for hydrogen peroxide reduction reaction in 0.1 mol/L PBS electrolyte and the limit of detection of H2O2 is estimated to be 0.035 mmol/L at a signal-to-noise ratio of 3 with a wide linear detection range from 50 μmol/L to 15 mmol/L （R^2 = 0.999）. Compared with the pure CMF, the Fe3C/NG exhibited higher catalytic activity, more stable response, lower detection limit, higher selectivity and a wider detection range, which could be attributed to the synergic effect between the two types of active sites from the iron carbide species and the nitrogen-doped graphite carbon. Meanwhile, the large surface area, high conductivity and the improved mass transport from the 3D porous material can also promote the electrochemical sensing performance. Moreover, the Fe3C/ NG-based electrochemical sensor showed high anti-interference ability and stability for H2O2 detection. Thus, the novel and low-cost Fe3C/NG composite may be a prom- ising alternative to noble metals and offer potential appli- cations in various types of electrochemical sensors, bioelectronic devices and catalysts.展开更多
基金Supported by the National Natural Science Foundation of China(No.50832001)the Science and Technology Develop-ment Program of Jilin Province, China(No.20070501)
文摘We proposed a new way to synthesize a nanocomposite consisted of cementite Fe3C nanoparticles and amorphous carbon by radio frequency plasma-enhanced chemical vapor deposition. Transmission electron microscope images show the existence of nanometric dark grains（Fe3C） embedded in a light matrix（amorphous carbon） in the samples. X-ray photoelectron spectroscopy experiment exhibit that the chemical bonding state in the films corresponded to sp3/sp2 amorphous carbon, sp^3 C-N（287.3 eV） and C15 in Fe3C（283.5 eV）. With increasing deposition time, the ratio of amorphous carbon increased. The magnetic measurements show that the value of in-lane coercivity increased with increasing carbon matrix concentration（from about 6.56× 10^3 A/m for film without carbon structures to approximately 2.77× 10^4 and 5.81 × 10^4 AJm for nanocomposite films at room temperature and 10 K, respectively）. The values of saturation magnetization for the synthesized nanocomposites were lower than that of the bulk Fe3C （ 140 Am^2/kg）.
基金supported by the National Natural Science Foundation of China (21275136)the Natural Science Foundation of Jilin Province (201215090)
文摘Fe3C-functionalized three-dimensional （3D） porous nitrogen-doped graphite carbon composites （Fe3C/ NG） were synthesized via a facile solution-based impreg- nation and pyrolysis strategy using the commercially available melamine foam and FeC13 as precursors. The structural characterizations confirmed that Fe3C nanoparticles with an average core size about 122 nm were assembled on the surface of the carbonized melamine foam （CMF） skeletons. The electrochemical measurements demonstrated the superior electrocatalytic activity of the advanced Fe3C/NG composite for hydrogen peroxide reduction reaction in 0.1 mol/L PBS electrolyte and the limit of detection of H2O2 is estimated to be 0.035 mmol/L at a signal-to-noise ratio of 3 with a wide linear detection range from 50 μmol/L to 15 mmol/L （R^2 = 0.999）. Compared with the pure CMF, the Fe3C/NG exhibited higher catalytic activity, more stable response, lower detection limit, higher selectivity and a wider detection range, which could be attributed to the synergic effect between the two types of active sites from the iron carbide species and the nitrogen-doped graphite carbon. Meanwhile, the large surface area, high conductivity and the improved mass transport from the 3D porous material can also promote the electrochemical sensing performance. Moreover, the Fe3C/ NG-based electrochemical sensor showed high anti-interference ability and stability for H2O2 detection. Thus, the novel and low-cost Fe3C/NG composite may be a prom- ising alternative to noble metals and offer potential appli- cations in various types of electrochemical sensors, bioelectronic devices and catalysts.
