Three-dimensional(3D)graphene monoliths are a new carbon material,that has tremendous potential in the fields of energy conversion and storage.They can solve the limitations of two-dimensional(2D)graphene sheets,inclu...Three-dimensional(3D)graphene monoliths are a new carbon material,that has tremendous potential in the fields of energy conversion and storage.They can solve the limitations of two-dimensional(2D)graphene sheets,including interlayer restacking,high contact resistance,and insufficient pore accessibility.By constructing interconnected porous networks,3D graphenes not only retain the intrinsic advantages of 2D graphene sheets,such as high specific surface area,excellent electrical and thermal conductivities,good mechanical properties,and outstanding chemical stability,but also enable efficient mass transport of external fluid species.We summarize the fabrication methods for 3D graphenes,with a particular focus on their applications in energy-related systems.Techniques including chemical reduction assembly,chemical vapor deposition,3D printing,chemical blowing,and zinc-tiered pyrolysis have been developed to change their pore structure and elemental composition,and ways in which they can be integrated with functional components.In terms of energy conversion and storage,they have found broad use in buffering mechanical impacts,suppressing noise,photothermal conversion,electromagnetic shielding and absorption.They have also been used in electrochemical energy systems such as supercapacitors,secondary batteries,and electrocatalysis.By reviewing recent progress in structural design and new applications,we also discuss the problems these materials face,including scalable fabrication and precise pore structure control,and possible new applications.展开更多
The Majorana zero modes in vortex cores are of extensive interest in the context of topological quantum computing.However,a zero-energy bound state may arise accidentally but is not necessarily a Majorana zero mode.Su...The Majorana zero modes in vortex cores are of extensive interest in the context of topological quantum computing.However,a zero-energy bound state may arise accidentally but is not necessarily a Majorana zero mode.Such accidental zero modes should be carefully ruled out in experiment in order to identify the genuine Majorana zero modes.We show that in a spin-orbital coupled multi-band superconductor,such as the iron-selenide superconductor,accidental zero modes indeed arise in the vortex core if the pairing symmetry is the so-called nodeless d-wave(defined in the absence of spin-orbital coupling).Instead,if the pairing sym-metry is s_(++)or s_(+−)with respect to the Fermi pockets split by the spin-orbital coupling,the accidental zero modes do not appear in the limit of weak spin-orbital coupling.Our results are not only important in the experimental identification of Majorana zero modes,but also provide an avenue to pinpoint the pairing symmetry of the iron-selenide superconductor.展开更多
基金supported by National Natural Science Foundation of China(52272039,U23B2075,51972168)Key Research and Development Program in Jiangsu Province(BE2023085)Natural Science Foundation of Jiangsu Province of China(BK20231406)。
文摘Three-dimensional(3D)graphene monoliths are a new carbon material,that has tremendous potential in the fields of energy conversion and storage.They can solve the limitations of two-dimensional(2D)graphene sheets,including interlayer restacking,high contact resistance,and insufficient pore accessibility.By constructing interconnected porous networks,3D graphenes not only retain the intrinsic advantages of 2D graphene sheets,such as high specific surface area,excellent electrical and thermal conductivities,good mechanical properties,and outstanding chemical stability,but also enable efficient mass transport of external fluid species.We summarize the fabrication methods for 3D graphenes,with a particular focus on their applications in energy-related systems.Techniques including chemical reduction assembly,chemical vapor deposition,3D printing,chemical blowing,and zinc-tiered pyrolysis have been developed to change their pore structure and elemental composition,and ways in which they can be integrated with functional components.In terms of energy conversion and storage,they have found broad use in buffering mechanical impacts,suppressing noise,photothermal conversion,electromagnetic shielding and absorption.They have also been used in electrochemical energy systems such as supercapacitors,secondary batteries,and electrocatalysis.By reviewing recent progress in structural design and new applications,we also discuss the problems these materials face,including scalable fabrication and precise pore structure control,and possible new applications.
基金supported by National Key R&D Program of China(Grant No.2022YFA1403201)and National Natural Science Foundation of China(Grant No.12374147,12274205 and 92365203).
文摘The Majorana zero modes in vortex cores are of extensive interest in the context of topological quantum computing.However,a zero-energy bound state may arise accidentally but is not necessarily a Majorana zero mode.Such accidental zero modes should be carefully ruled out in experiment in order to identify the genuine Majorana zero modes.We show that in a spin-orbital coupled multi-band superconductor,such as the iron-selenide superconductor,accidental zero modes indeed arise in the vortex core if the pairing symmetry is the so-called nodeless d-wave(defined in the absence of spin-orbital coupling).Instead,if the pairing sym-metry is s_(++)or s_(+−)with respect to the Fermi pockets split by the spin-orbital coupling,the accidental zero modes do not appear in the limit of weak spin-orbital coupling.Our results are not only important in the experimental identification of Majorana zero modes,but also provide an avenue to pinpoint the pairing symmetry of the iron-selenide superconductor.
