Well aligned nanotubes with diameter of 30—50 nm have been synthesized on a porous alumina template by microwave plasma enhanced chemical vapor deposition (MW PECVD). By this means, the control over either diameter o...Well aligned nanotubes with diameter of 30—50 nm have been synthesized on a porous alumina template by microwave plasma enhanced chemical vapor deposition (MW PECVD). By this means, the control over either diameter or length of the nanotubes could be realized. The hollow structure and vertically aligned features have been verified by scanning electron and transmission electron microscopic images. In comparison with the reported fabrication methods, lower synthesis temperature (below 520 ℃) and simpler process (no negative dc bias applied) have been achieved, which could be of great importance for both theoretical research and pratical applications.展开更多
Hierarchical nitrogen-doped carbon nanocages （hNCNC） with large specific surface areas were used as a catalyst support to immobilize Pt nanoparticles by a microwave-assisted polyol method. The Pt/hNCNC catalyst with...Hierarchical nitrogen-doped carbon nanocages （hNCNC） with large specific surface areas were used as a catalyst support to immobilize Pt nanoparticles by a microwave-assisted polyol method. The Pt/hNCNC catalyst with 20 wt% loading has a homogeneous dispersion of Pt nanoparticles with the average size of 3.3 nm, which is smaller than 4.3 and 4.9 nm for the control catalysts with the same loading supported on hierarchical carbon nanocages （hCNC） and commercial Vulcan XC-72, respec- tively. Accordingly, Pt/hNCNC has a larger electrochemical surface area than Pt/hCNC and Pt/XC-72. The Pt/hNCNC catalyst exhibited excellent electrocatalytic activity and stability for methanol oxidation, which was better than the control catalysts. This was attributed to the en- hanced interaction between Pt and hNCNC due to nitrogen participation in the anchoring function. By making use of the unique advantages of the hNCNC support, a heavy Pt loading up to 60 wt% was prepared without serious agglomeration, which gave a high peak-current density per unit mass of catalyst of 95.6 mA/mg for achieving a high power density. These results showed the potential of the Pt/hNCNC catalyst for methanol oxidation and of the new hNCNC support for wide applications.展开更多
Quasi - periodically intermittent hollow - cavity - stacked one - dimensional carbon nanostructures were obtained by microwave plasma chemical vapor deposition from the mixture of CH 4 and N 2 on Fe/γ - Al 2 O 3 cata...Quasi - periodically intermittent hollow - cavity - stacked one - dimensional carbon nanostructures were obtained by microwave plasma chemical vapor deposition from the mixture of CH 4 and N 2 on Fe/γ - Al 2 O 3 catalyst.This structure was characterized by transmission electron microscope(TEM),high - resolution TEM and X - ray energy dispersive spectral analysis.The results indicate that the trace impurity of nitrogen might account mainly for the formation of these novel nanostructures.The structural units in these one - dimensional carbon nanostructures are full of nanocavities,which may be of potential importance in hydrogen storage.展开更多
A multifunctional apparatus for microwave plasma reaction has been set up, which can be used in the fields such as Chemical synthesis, surface modification, and heterogeneous catalysis. This apparatus has laid an exp...A multifunctional apparatus for microwave plasma reaction has been set up, which can be used in the fields such as Chemical synthesis, surface modification, and heterogeneous catalysis. This apparatus has laid an experimental foundation for new methods, new technologies, and new train of thoughts to be explored.展开更多
文摘Well aligned nanotubes with diameter of 30—50 nm have been synthesized on a porous alumina template by microwave plasma enhanced chemical vapor deposition (MW PECVD). By this means, the control over either diameter or length of the nanotubes could be realized. The hollow structure and vertically aligned features have been verified by scanning electron and transmission electron microscopic images. In comparison with the reported fabrication methods, lower synthesis temperature (below 520 ℃) and simpler process (no negative dc bias applied) have been achieved, which could be of great importance for both theoretical research and pratical applications.
基金supported by the National Natural Science Foundation of China(21473089,51232003,21373108,51571110,21573107)the Nation-al Basic Research Program of China(973 Program,2013CB932902)+2 种基金Suzhou Science and Technology Projects(ZXG2013025)Changzhou Science and Technology Projects(CE20130032)supported by a Project Funded by the Technology Support Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Hierarchical nitrogen-doped carbon nanocages （hNCNC） with large specific surface areas were used as a catalyst support to immobilize Pt nanoparticles by a microwave-assisted polyol method. The Pt/hNCNC catalyst with 20 wt% loading has a homogeneous dispersion of Pt nanoparticles with the average size of 3.3 nm, which is smaller than 4.3 and 4.9 nm for the control catalysts with the same loading supported on hierarchical carbon nanocages （hCNC） and commercial Vulcan XC-72, respec- tively. Accordingly, Pt/hNCNC has a larger electrochemical surface area than Pt/hCNC and Pt/XC-72. The Pt/hNCNC catalyst exhibited excellent electrocatalytic activity and stability for methanol oxidation, which was better than the control catalysts. This was attributed to the en- hanced interaction between Pt and hNCNC due to nitrogen participation in the anchoring function. By making use of the unique advantages of the hNCNC support, a heavy Pt loading up to 60 wt% was prepared without serious agglomeration, which gave a high peak-current density per unit mass of catalyst of 95.6 mA/mg for achieving a high power density. These results showed the potential of the Pt/hNCNC catalyst for methanol oxidation and of the new hNCNC support for wide applications.
文摘Quasi - periodically intermittent hollow - cavity - stacked one - dimensional carbon nanostructures were obtained by microwave plasma chemical vapor deposition from the mixture of CH 4 and N 2 on Fe/γ - Al 2 O 3 catalyst.This structure was characterized by transmission electron microscope(TEM),high - resolution TEM and X - ray energy dispersive spectral analysis.The results indicate that the trace impurity of nitrogen might account mainly for the formation of these novel nanostructures.The structural units in these one - dimensional carbon nanostructures are full of nanocavities,which may be of potential importance in hydrogen storage.
文摘A multifunctional apparatus for microwave plasma reaction has been set up, which can be used in the fields such as Chemical synthesis, surface modification, and heterogeneous catalysis. This apparatus has laid an experimental foundation for new methods, new technologies, and new train of thoughts to be explored.
