Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of normal metal/dx2-y2 + idxy mixed wave superconductor graphene junctions. It is found that the conductance spectra vary ...Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of normal metal/dx2-y2 + idxy mixed wave superconductor graphene junctions. It is found that the conductance spectra vary strongly with the orientation of the gap and the amplitude ratio (Δ1/Δ0) of two components for dx2-y2 + idxy mixed wave. The zero bias conductance is nearly 2 and the conductance peak vanishes in doped graphene for a = 0 and Δ1/Δ0 = 1. The conductance increases with increasing the amplitude ratio of two components for α =π/4 and Δ1/Δ0 -- 1. The ZBCP becomes observable wide with 1 〈 EF/Δ0 〈 100 for α= π/4 and Δ1/Δ0 = 1. This property is different from that in normal metal/dx2-y2 wave superconductor graphene junctions.展开更多
Taking advantage of the nitrogen(N)-participation and large surface area of N-doped carbon nanocages(NCNCs),the Co Ox nanocrystals are conveniently immobilized onto the NCNCs with high dispersion.The Co Ox/NCNCs hybri...Taking advantage of the nitrogen(N)-participation and large surface area of N-doped carbon nanocages(NCNCs),the Co Ox nanocrystals are conveniently immobilized onto the NCNCs with high dispersion.The Co Ox/NCNCs hybrid exists in the mixed valence with predominant Co O over Co3O4 and demonstrates superb oxygen reduction reaction activity and stability remaining^94%current density even after operation over 100 h.These results suggest a promising strategy to develop advanced electrocatalysts with the novel NCNCs or even beyond.展开更多
Li-ion hybrid supercapacitors(Li-HSCs) have attracted increasing attention as a promising energy storage device with both high power and energy densities. We report a facile two-step hydrothermal method to prepare t...Li-ion hybrid supercapacitors(Li-HSCs) have attracted increasing attention as a promising energy storage device with both high power and energy densities. We report a facile two-step hydrothermal method to prepare the orthorhombic niobium oxide(T-Nb2O5) nanosheets supported on nitrogen and sulfur co-doped graphene(T-Nb205/NS-G) as anode for Li-HSCs. X-ray diffraction and morphological analysis show that the T-Nb2O5 nano sheets successfully and uniformly distributed on the NS-G sheets. The T-Nb2O5/NS-G hybrid exhibits great rate capability(capacity retention of63.1% from 0.05 to 5 A g^-1) and superior cycling stability(a low capacity fading of ~6.4% after 1000 cycles at 0.5 A g^-1).The full-cell consisting of T-Nb2O5/NS-G and active carbon(AC) results in high energy density(69.2 W h kg^-1 at0.1 A g^-1), high power density(9.17 kW kg^-1) and excellent cycling stability(95% of the initial energy after 3000 cycles).This excellent performance is mainly attributed to the highly conductive NS-G sheets, the uniformly distributed T-Nb2O5 nano sheets and the synergetic effects between them. These encouraging performances confirm that the obtained TNb2O5/NS-G has promising prospect as the anode for Li-HSCs.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No. 11074088
文摘Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of normal metal/dx2-y2 + idxy mixed wave superconductor graphene junctions. It is found that the conductance spectra vary strongly with the orientation of the gap and the amplitude ratio (Δ1/Δ0) of two components for dx2-y2 + idxy mixed wave. The zero bias conductance is nearly 2 and the conductance peak vanishes in doped graphene for a = 0 and Δ1/Δ0 = 1. The conductance increases with increasing the amplitude ratio of two components for α =π/4 and Δ1/Δ0 -- 1. The ZBCP becomes observable wide with 1 〈 EF/Δ0 〈 100 for α= π/4 and Δ1/Δ0 = 1. This property is different from that in normal metal/dx2-y2 wave superconductor graphene junctions.
基金supported by the National Natural Science Foundation of China(51232003,21473089,21373108,21173115)the National Basic Research Program of China(2013CB932902)+2 种基金Jiangsu Province Science and Technology Support Project(BE2012159)Suzhou Science and Technology Plan projects(ZXG2013025)National Science Fund for Talent Training in Basic Science(J1103310)
文摘Taking advantage of the nitrogen(N)-participation and large surface area of N-doped carbon nanocages(NCNCs),the Co Ox nanocrystals are conveniently immobilized onto the NCNCs with high dispersion.The Co Ox/NCNCs hybrid exists in the mixed valence with predominant Co O over Co3O4 and demonstrates superb oxygen reduction reaction activity and stability remaining^94%current density even after operation over 100 h.These results suggest a promising strategy to develop advanced electrocatalysts with the novel NCNCs or even beyond.
基金supported by the National Natural Science Foundation of China(21576138 and 51572127)China-Israel Cooperative Program (2016YFE0129900)+5 种基金Program for NCET-12-0629,PhD Program Foundation of Ministry of Education of China (20133219110018)the Natural Science Foundation of Jiangsu Province (BK20160828)Post-Doctoral Foundation(1501016B)Six Major Talent Summit (XNY-011)PAPD of Jiangsu Provincethe program for Science and Technology Innovative Research Team in Universities of Jiangsu Province,China
文摘Li-ion hybrid supercapacitors(Li-HSCs) have attracted increasing attention as a promising energy storage device with both high power and energy densities. We report a facile two-step hydrothermal method to prepare the orthorhombic niobium oxide(T-Nb2O5) nanosheets supported on nitrogen and sulfur co-doped graphene(T-Nb205/NS-G) as anode for Li-HSCs. X-ray diffraction and morphological analysis show that the T-Nb2O5 nano sheets successfully and uniformly distributed on the NS-G sheets. The T-Nb2O5/NS-G hybrid exhibits great rate capability(capacity retention of63.1% from 0.05 to 5 A g^-1) and superior cycling stability(a low capacity fading of ~6.4% after 1000 cycles at 0.5 A g^-1).The full-cell consisting of T-Nb2O5/NS-G and active carbon(AC) results in high energy density(69.2 W h kg^-1 at0.1 A g^-1), high power density(9.17 kW kg^-1) and excellent cycling stability(95% of the initial energy after 3000 cycles).This excellent performance is mainly attributed to the highly conductive NS-G sheets, the uniformly distributed T-Nb2O5 nano sheets and the synergetic effects between them. These encouraging performances confirm that the obtained TNb2O5/NS-G has promising prospect as the anode for Li-HSCs.