We numerically investigate the effect of in-plane bending strain on valley-resolved conductance and valley polarization in a graphene nanoribbon with zigzag edges.The central region of the nanoribbon is bent into an a...We numerically investigate the effect of in-plane bending strain on valley-resolved conductance and valley polarization in a graphene nanoribbon with zigzag edges.The central region of the nanoribbon is bent into an arc with central angleφ.We find that the bending strain reduces the conductance but enhances the valley polarization.In the valley-resolved conductance spectra,there exist single-valley plateaus near the Dirac points and distinct Fano-type dips.Accordingly,a plateau of full valley polarization appears,which expands significantly at largeφ.At valleyresolved conductance dips,the valley polarization can be much larger than that in the unstrained case.The bending-induced enhancement of valley polarization can be explained by the features of pseudo-Landau levels in the bent region.Strain-induced valley polarization depends nonmonotonously on the nanoribbon width.These findings could be helpful in designing valleytronic devices with flexibility.展开更多
Adsorption as an effective technique for the remediation of wastewater has been widely used in industrial wastewater treatment due to the advantage of cost-effectiveness,availability of the adsorbent and ease of opera...Adsorption as an effective technique for the remediation of wastewater has been widely used in industrial wastewater treatment due to the advantage of cost-effectiveness,availability of the adsorbent and ease of operation.However,the low adsorption capacity of the reported adsorbents is still a challenge for wastewater treatment with highefficiency.Here,we developed a super adsorbent(SUA-1),which was a kind of porous carbon nanofibers derived from a composite of PAN-based electrospinning and ZIF-8(PAN/ZIF-8)via simple heat treatment process.The asprepared SUA showed an ultra-high adsorption capacity for adsorbing methyl blue(MB)at nearly three times its own weight,as high as 2998.18 mg/g.A series tests demonstrated that the pore-making effect of ZIF-8 during heat treatment process endowed high BET surface area and generated ZnO components as chemical adsorption center.Under the synergistic effect of bonding and non-bonding forces including ionic bond,electrostatic interaction,andπ-πinteraction,the adsorption capacity has been greatly improved.In view of promising efficiency,this work provides guidance and insights for the preparation of highly efficient adsorbents based on electrospinning derived porous carbon nanofibers.展开更多
基金supported by the public welfare project(Normal Education Quality Improvement Plan)by the China Education Development Foundation(Grant No.TZJH202202)the National Natural Science Foundation of China(Grant No.12274370)。
文摘We numerically investigate the effect of in-plane bending strain on valley-resolved conductance and valley polarization in a graphene nanoribbon with zigzag edges.The central region of the nanoribbon is bent into an arc with central angleφ.We find that the bending strain reduces the conductance but enhances the valley polarization.In the valley-resolved conductance spectra,there exist single-valley plateaus near the Dirac points and distinct Fano-type dips.Accordingly,a plateau of full valley polarization appears,which expands significantly at largeφ.At valleyresolved conductance dips,the valley polarization can be much larger than that in the unstrained case.The bending-induced enhancement of valley polarization can be explained by the features of pseudo-Landau levels in the bent region.Strain-induced valley polarization depends nonmonotonously on the nanoribbon width.These findings could be helpful in designing valleytronic devices with flexibility.
基金Natural Science Foundation of China(22134005,22204011)Chongqing Talents Program for Outstanding Scientists(cstc2021ycjh-bgzxm0179)。
文摘Adsorption as an effective technique for the remediation of wastewater has been widely used in industrial wastewater treatment due to the advantage of cost-effectiveness,availability of the adsorbent and ease of operation.However,the low adsorption capacity of the reported adsorbents is still a challenge for wastewater treatment with highefficiency.Here,we developed a super adsorbent(SUA-1),which was a kind of porous carbon nanofibers derived from a composite of PAN-based electrospinning and ZIF-8(PAN/ZIF-8)via simple heat treatment process.The asprepared SUA showed an ultra-high adsorption capacity for adsorbing methyl blue(MB)at nearly three times its own weight,as high as 2998.18 mg/g.A series tests demonstrated that the pore-making effect of ZIF-8 during heat treatment process endowed high BET surface area and generated ZnO components as chemical adsorption center.Under the synergistic effect of bonding and non-bonding forces including ionic bond,electrostatic interaction,andπ-πinteraction,the adsorption capacity has been greatly improved.In view of promising efficiency,this work provides guidance and insights for the preparation of highly efficient adsorbents based on electrospinning derived porous carbon nanofibers.
