The orientation construction of S-doped porous carbon fibers(SPCFs)is realized by the facile template-directed methodology using asphalt powder as carbon source.The unique fiber-like morphology without destruction can...The orientation construction of S-doped porous carbon fibers(SPCFs)is realized by the facile template-directed methodology using asphalt powder as carbon source.The unique fiber-like morphology without destruction can be well duplicated from the template by the developed methodology.MgSO4 fibers serve as both templates and S dopant,realizing the in-situ S doping into carbon frameworks.The effects of different reaction temperatures on the yield and S doping level of SPCFs are investigated.The S doping can not only significantly enhance the electrical conductivity,but also introduce more defects or disorders.As anode material for lithium ion batteries(LIBs),SPCFs electrode delivers better rate capability than undoped PCFs.And the capacity of SPCFs electrode retains around 90%after 300 cycles at 2 A g1,exhibiting good cycling stability.As the electrocatalysts for fuel cells,the onset potentials of SPCFs obtained at 800 and 900C are concentrated at 0.863 V,and the higher kinetic current densities at 0.4 V of them are larger than that of PCFs,demonstrating the superior electrocatalytic performance.Due to the synergistic effect of abundant pore channels and S doping,SPCFs electrode exhibits superior electrochemical performances as anode for LIBs and elecctrocatalyst for fuel cells,respectively.Additionally,the oriented conversion of asphalt powder into high-performance electrode material in this work provides a new way for the high value application of asphalt.展开更多
An inclusion complex of cyclic bis(zinc porphyrin) 1 with 5,15-dipyridylporphyrin derivative 3 has been designed and constructed. The complex formation is induced by Zn-N coordination, and is robust (Kassoc ~ 106 L/mo...An inclusion complex of cyclic bis(zinc porphyrin) 1 with 5,15-dipyridylporphyrin derivative 3 has been designed and constructed. The complex formation is induced by Zn-N coordination, and is robust (Kassoc ~ 106 L/mol) due to the presence of the cage effect of cyclic bis(zinc porphyrin). The cage-like complex as an entity is stable enough, and also convenient to achieve relative movement between the bis(zinc porphyrin) host and the dipyridylporphyrin vip connected by Zn-N coordination. The characteristics of these assemblies have been demonstrated by 1 H NMR, UV-vis, and fluorescence spectra. The results show its potential applications as a molecular gyroscope in molecular machines.展开更多
文摘The orientation construction of S-doped porous carbon fibers(SPCFs)is realized by the facile template-directed methodology using asphalt powder as carbon source.The unique fiber-like morphology without destruction can be well duplicated from the template by the developed methodology.MgSO4 fibers serve as both templates and S dopant,realizing the in-situ S doping into carbon frameworks.The effects of different reaction temperatures on the yield and S doping level of SPCFs are investigated.The S doping can not only significantly enhance the electrical conductivity,but also introduce more defects or disorders.As anode material for lithium ion batteries(LIBs),SPCFs electrode delivers better rate capability than undoped PCFs.And the capacity of SPCFs electrode retains around 90%after 300 cycles at 2 A g1,exhibiting good cycling stability.As the electrocatalysts for fuel cells,the onset potentials of SPCFs obtained at 800 and 900C are concentrated at 0.863 V,and the higher kinetic current densities at 0.4 V of them are larger than that of PCFs,demonstrating the superior electrocatalytic performance.Due to the synergistic effect of abundant pore channels and S doping,SPCFs electrode exhibits superior electrochemical performances as anode for LIBs and elecctrocatalyst for fuel cells,respectively.Additionally,the oriented conversion of asphalt powder into high-performance electrode material in this work provides a new way for the high value application of asphalt.
基金Supported by the 973 Program (Grant No. 2006CB932900)National Natural Science Foundation of China (Grant Nos. 20802038 and 20721062)Tianjin Natural Science Foundation (Grant No. 07QTPTJC29700).
文摘An inclusion complex of cyclic bis(zinc porphyrin) 1 with 5,15-dipyridylporphyrin derivative 3 has been designed and constructed. The complex formation is induced by Zn-N coordination, and is robust (Kassoc ~ 106 L/mol) due to the presence of the cage effect of cyclic bis(zinc porphyrin). The cage-like complex as an entity is stable enough, and also convenient to achieve relative movement between the bis(zinc porphyrin) host and the dipyridylporphyrin vip connected by Zn-N coordination. The characteristics of these assemblies have been demonstrated by 1 H NMR, UV-vis, and fluorescence spectra. The results show its potential applications as a molecular gyroscope in molecular machines.
