In this work,a novel Bi_(2)S_(3)/Bi_(5)O_(7)I p-n heterojunction with three-dimensional rod-like nanostructure was successfully constructed through an in-situ topotactic ion exchange approach.A possible evolution mech...In this work,a novel Bi_(2)S_(3)/Bi_(5)O_(7)I p-n heterojunction with three-dimensional rod-like nanostructure was successfully constructed through an in-situ topotactic ion exchange approach.A possible evolution mech-anism from Bi_(5)O_(7)I nanobelts(NBs)into Bi_(2)S_(3)/Bi_(5)O_(7)I rod-like heterostructures(BSI RHs)was proposed,depicting the self-assembly process of internal Bi_(5)O_(7)I NBs and outside networks interwoven by Bi_(2)S_(3)nanorods(NRs),which abided by the Ostwald ripening and epitaxial growth.Owing to the formation of p-n heterojunction and rich oxygen vacancies(OVs),the visible-light absorption ability and separation of photogenerated charge carriers of BSI RHs were highly promoted,leading to a greatly improved photocatalytic ability than that of Bi_(2)S_(3)and Bi_(5)O_(7)I.BSI-1 exhibited the strongest photocatalytic performance,and almost all rhodamine B(RhB)and Pseudomonas aeruginosa(P.aeruginosa)can be thoroughly removed within 90 min.Moreover,a possible photocatalytic mechanism of BSI RHs was proposed based on the tests of active species trapping,electron spin resonance(ESR),photoelectrochemistry(PEC),and photoluminescence(PL)combined with the density functional theory(DFT)simulated computation,vali-dating the dominating roles of·O_(2)^(−)and h+during the photocatalytic process.This work is expected to motivate further efforts for developing novel heterostructures with highly efficient photocatalytic performances,which presents a promising application prospect in the fields of energy and environment.展开更多
The RMn_(2)O_(5) manganite compounds represent one class of multiferroic family with magnetic origins,which has been receiving continuous attention in the past decade.So far,our understanding of the magnetic origins f...The RMn_(2)O_(5) manganite compounds represent one class of multiferroic family with magnetic origins,which has been receiving continuous attention in the past decade.So far,our understanding of the magnetic origins for ferroelectricity in RMn_(2)O_(5) is associated with the nearly collinear antiferromagnetic structure of Mn ions,while the exchange striction induced ionic displacements are the consequence of the spin frustration competitions.While this scenario may be applied to almost all RMn_(2)O_(5) members,its limitation is either clear:the temperature-dependent behaviors of electric polarization and its responses to external stimuli are seriously materials dependent.These inconsistences raise substantial concern with the state-of-the-art physics of ferroelectricity in RMn_(2)O_(5).In this mini-review,we present our recent experimental results on the roles of the 4f moments from R ions which are intimately coupled with the 3d moments from Mn ions.DyMn_(2)O_(5) is a golden figure for illustrating these roles.It is demonstrated that the spin structure accommodates two nearly collinear sublattices which generate respectively two ferroelectric(FE)sublattices,enabling DyMn_(2)O_(5) an emergent ferrielectric(FIE)system rarely identified in magnetically induced FEs.The evidence is presented from several aspects,including FIE-like phenomena and magnetoelectric responses,proposed structural model,and experimental check by nonmagnetic substitutions of the 3d and 4f moments.Additional perspectives regarding possible challenges in understanding the multiferroicity of RMn_(2)O_(5) as a generalized scenario are discussed.展开更多
基金This work was financially supported by the Basic Scientific Fund for National Public Research Institutes of China(Nos.2020S02 and 2019Y03)the Key Research and Development Program of Shandong Province(Major Scientific and Technological Innovation Project)(No.2019JZZY020711)+1 种基金the Young Elite Scientists Sponsor-ship Program by CAST(No.YESS20210201)National Natural Science Foundation of China(No.51702328).
文摘In this work,a novel Bi_(2)S_(3)/Bi_(5)O_(7)I p-n heterojunction with three-dimensional rod-like nanostructure was successfully constructed through an in-situ topotactic ion exchange approach.A possible evolution mech-anism from Bi_(5)O_(7)I nanobelts(NBs)into Bi_(2)S_(3)/Bi_(5)O_(7)I rod-like heterostructures(BSI RHs)was proposed,depicting the self-assembly process of internal Bi_(5)O_(7)I NBs and outside networks interwoven by Bi_(2)S_(3)nanorods(NRs),which abided by the Ostwald ripening and epitaxial growth.Owing to the formation of p-n heterojunction and rich oxygen vacancies(OVs),the visible-light absorption ability and separation of photogenerated charge carriers of BSI RHs were highly promoted,leading to a greatly improved photocatalytic ability than that of Bi_(2)S_(3)and Bi_(5)O_(7)I.BSI-1 exhibited the strongest photocatalytic performance,and almost all rhodamine B(RhB)and Pseudomonas aeruginosa(P.aeruginosa)can be thoroughly removed within 90 min.Moreover,a possible photocatalytic mechanism of BSI RHs was proposed based on the tests of active species trapping,electron spin resonance(ESR),photoelectrochemistry(PEC),and photoluminescence(PL)combined with the density functional theory(DFT)simulated computation,vali-dating the dominating roles of·O_(2)^(−)and h+during the photocatalytic process.This work is expected to motivate further efforts for developing novel heterostructures with highly efficient photocatalytic performances,which presents a promising application prospect in the fields of energy and environment.
基金supported by the Natural Science Foundation of China(Grant Nos.11234005 and 51431006)the National 973 Projects of China(Grant No.2011CB922101).
文摘The RMn_(2)O_(5) manganite compounds represent one class of multiferroic family with magnetic origins,which has been receiving continuous attention in the past decade.So far,our understanding of the magnetic origins for ferroelectricity in RMn_(2)O_(5) is associated with the nearly collinear antiferromagnetic structure of Mn ions,while the exchange striction induced ionic displacements are the consequence of the spin frustration competitions.While this scenario may be applied to almost all RMn_(2)O_(5) members,its limitation is either clear:the temperature-dependent behaviors of electric polarization and its responses to external stimuli are seriously materials dependent.These inconsistences raise substantial concern with the state-of-the-art physics of ferroelectricity in RMn_(2)O_(5).In this mini-review,we present our recent experimental results on the roles of the 4f moments from R ions which are intimately coupled with the 3d moments from Mn ions.DyMn_(2)O_(5) is a golden figure for illustrating these roles.It is demonstrated that the spin structure accommodates two nearly collinear sublattices which generate respectively two ferroelectric(FE)sublattices,enabling DyMn_(2)O_(5) an emergent ferrielectric(FIE)system rarely identified in magnetically induced FEs.The evidence is presented from several aspects,including FIE-like phenomena and magnetoelectric responses,proposed structural model,and experimental check by nonmagnetic substitutions of the 3d and 4f moments.Additional perspectives regarding possible challenges in understanding the multiferroicity of RMn_(2)O_(5) as a generalized scenario are discussed.
