Plasmon-induced hot electron can transfer from noble metal to its cohesive semiconductor in their heterostructure to initiate the photocatalytic reaction upon resonance excitation.However,the co-excitation of semicond...Plasmon-induced hot electron can transfer from noble metal to its cohesive semiconductor in their heterostructure to initiate the photocatalytic reaction upon resonance excitation.However,the co-excitation of semiconductor in the heterostructure would also lead to the inversus transfer of photo-electron from semiconductor to noble metal,which inevitably limits the use of active electrons.After co-excitation of both localized surface plasmon resonance(LSPR)of noble metal and interband transition of semiconductor,the interfacial electron transfer process strongly depends on the energy band configuration of their heterostructure.When the Au content in the AuAg alloy nanoparticles(NPs)changes from 0 to 100 at.%,the interfacial energy band configuration at AuAg NPs/TiO_(2) NPs in the electrospun nanofibers(NFs)shifts from Ohmic to Schottky contacts.Further investigation finds that the optimal Schottky barrier configuration in Au_(0.25)Ag_(0.75)/TiO_(2) NFs can not only boost the plasmon-induced hot electron transfer from Au_(0.25)Ag_(0.75) to TiO_(2) NPs,but also suppresses the backflow of photo-electrons from TiO_(2) to Au_(0.25)Ag_(0.75) NPs in NFs.Thus,upon UV-visible light irradiation,the CO_(2) photo-reduction activity of Au_(0.25)Ag_(0.75)/TiO_(2) NFs is~3 and~2 times higher than that of either Ag/TiO_(2) or Au/TiO_(2) NFs.展开更多
Noble metal clusters is an emerging class of fluorescent probes, avoiding most of the drawbacks of common fluorescent compounds, and they are simple to prepare and have good water solubility, good biocompatibility and...Noble metal clusters is an emerging class of fluorescent probes, avoiding most of the drawbacks of common fluorescent compounds, and they are simple to prepare and have good water solubility, good biocompatibility and excellent fluorescence properties. In this study, we have explored the synthesis of the cytidine mediated gold-silver nanoclusters （AuAg NCs） and applied it for both in vitro cellular imaging and tumor in vivo detection. Experimental results show that the as-prepared AuAg NCs can be used as a sensitive fluorescent probe for cancer cells/tissue de- tection. Especially, it is evident that under the relevant light irradiation with the wavelength of 488 nm, obviously bright fluorescence signal could be readily detected from focus location of inoculating tumor mouse, implying its possible application for the effective in vivo tumor bioimaging.展开更多
Converting CO_(2) under mild conditions by employing semiconductor photocatalysts is promising to address global environmental issues.However,the current CO_(2) conversion efficiency is limited by the difficulty activ...Converting CO_(2) under mild conditions by employing semiconductor photocatalysts is promising to address global environmental issues.However,the current CO_(2) conversion efficiency is limited by the difficulty activating the thermodynamically stable CO_(2) molecules.Constructing plasmonic nanoalloy-based photocatalytic systems with significant localized surface plasmon resonance(LSPR)is full of po-tential but remains a vast challenge.In this work,AuAg plasmonic nanoalloys were incorporated on CeO_(2) nanorods(designated as AuAg–CeO_(2))to achieve selective photoreduction of CO_(2).The result displays that Ag can serve as a superior electron modifier to promote the electron enrichment of Au,thus producing asymmetric charge distributions to boost the selective conversion of CO_(2).Furthermore,the improved LSPR effect on AuAg–CeO_(2) induces the generation of high-energy hot electrons under irradiation,enhancing the reactivity of electrons for CO_(2) photo-reduction.Due to the aforementioned effects,AuAg–CeO_(2) exhibits a high CO_(2)-to-CH4 performance of 92.6μmol g-1 through a 3-h test and a high CH4 selectivity of 94.5%,up to 2.6,8.7,and 17.1 times higher than the activity of Au–CeO_(2),pure CeO_(2),and Ag–CeO_(2),respectively.This work can provide a new perspective for con-structing high-performance catalysts for photocatalytic CO_(2) reduction.展开更多
Plasmonic metal nanomaterials with intrinsic surface–enhanced Raman scattering(SERS)and photothermal properties,especially AuAg nanoalloys with both the outstanding merits of Au and Ag nanocrystals,show huge applicat...Plasmonic metal nanomaterials with intrinsic surface–enhanced Raman scattering(SERS)and photothermal properties,especially AuAg nanoalloys with both the outstanding merits of Au and Ag nanocrystals,show huge application prospects in bacterial theranostics.However,the direct exposure of AuAg nanoalloys in external conditions probably cause undesirable reactions and poisonous metal ion leakage during SERS detection and photothermal antibacterial therapy process,which severely hinder bacterial theranostics applications.Herein,we report an ultrastable graphene–isolated AuAg nanoalloy(GAA)with AuAg core confined in few–layer graphitic shell as a versatile platform for bacterial detection and therapy.The encapsulation of graphene ensures the good stability of AuAg core,that its superior SERS and photothermal properties are therefore further guaranteed.GAA is used for SERS detection of two vital bacterial biomarkers(including corrosive cyanide and pyocyanin),exhibiting good SERS quantitative and multiplexing ability.GAA is further used for photothermal antibacterial therapy application,and ultrahigh antibacterial efficacies for both Gram–negative Escherichia coli and Gram–positive Staphylococcus aureus are achieved under 808 nm laser irradiation.This work proposes a valuable method to develop robust bacterial theranostic platform.展开更多
The mechanism of addition of separate atoms to a growing center is considered with application of model of a pair interpenetration of atoms. Features of geometrical model are related with the electronic structure of a...The mechanism of addition of separate atoms to a growing center is considered with application of model of a pair interpenetration of atoms. Features of geometrical model are related with the electronic structure of atoms and the Pauli＇s exclusion principle. The forces providing self-organization of atoms in the bulk of a condensed substance are shown. The calculated interatomic distances in graphite and alloys of gold with silver coincide with those known from experiments with accuracy of 0.1%.展开更多
基金supported by the National Natural Science Foundation of China(Nos.:22472021,U23A20102,12074055,22402021 and 62005036)Liaoning Revitalization Talents Program(XLYC2202036,XLYC1807176)+4 种基金Natural Science Foundation of Liaoning Province for Excellent Young Scholars(2022-YQ-13)Fundamental Research Funds for the Central Universities(044420250072)Dalian Science Foundation for Distinguished Young Scholars(2018RJ05)Natural Science Foundation of Liaoning Province(2023-MS-132)Joint Funds of the Science and Technology Program of Liaoning Province(No.2024JH2/102600101).
文摘Plasmon-induced hot electron can transfer from noble metal to its cohesive semiconductor in their heterostructure to initiate the photocatalytic reaction upon resonance excitation.However,the co-excitation of semiconductor in the heterostructure would also lead to the inversus transfer of photo-electron from semiconductor to noble metal,which inevitably limits the use of active electrons.After co-excitation of both localized surface plasmon resonance(LSPR)of noble metal and interband transition of semiconductor,the interfacial electron transfer process strongly depends on the energy band configuration of their heterostructure.When the Au content in the AuAg alloy nanoparticles(NPs)changes from 0 to 100 at.%,the interfacial energy band configuration at AuAg NPs/TiO_(2) NPs in the electrospun nanofibers(NFs)shifts from Ohmic to Schottky contacts.Further investigation finds that the optimal Schottky barrier configuration in Au_(0.25)Ag_(0.75)/TiO_(2) NFs can not only boost the plasmon-induced hot electron transfer from Au_(0.25)Ag_(0.75) to TiO_(2) NPs,but also suppresses the backflow of photo-electrons from TiO_(2) to Au_(0.25)Ag_(0.75) NPs in NFs.Thus,upon UV-visible light irradiation,the CO_(2) photo-reduction activity of Au_(0.25)Ag_(0.75)/TiO_(2) NFs is~3 and~2 times higher than that of either Ag/TiO_(2) or Au/TiO_(2) NFs.
文摘Noble metal clusters is an emerging class of fluorescent probes, avoiding most of the drawbacks of common fluorescent compounds, and they are simple to prepare and have good water solubility, good biocompatibility and excellent fluorescence properties. In this study, we have explored the synthesis of the cytidine mediated gold-silver nanoclusters （AuAg NCs） and applied it for both in vitro cellular imaging and tumor in vivo detection. Experimental results show that the as-prepared AuAg NCs can be used as a sensitive fluorescent probe for cancer cells/tissue de- tection. Especially, it is evident that under the relevant light irradiation with the wavelength of 488 nm, obviously bright fluorescence signal could be readily detected from focus location of inoculating tumor mouse, implying its possible application for the effective in vivo tumor bioimaging.
基金financially supported by the Key R&D Program of Shaanxi Province(No.2023-YBGY-323)Joint Funds of the National Natural Science Foundation of China(No.U22A20391)+4 种基金the National Natural Science Foundation of China(Nos.22078256,22308272)the High-level Innovation and Entrepreneurship Talent Project of Qinchuangyuan(No.2021QCYRC4-24)Innovation Capability Support Program of Shaanxi(No.2023-CX-TD-26)the“Young Talent Support Plan”of Xi'an Jiaotong University(No.HG6J021)the Higher Education Institution Academic Discipline Innovation and Talent Introduction Plan(“111 Plan”,No.B23025).
文摘Converting CO_(2) under mild conditions by employing semiconductor photocatalysts is promising to address global environmental issues.However,the current CO_(2) conversion efficiency is limited by the difficulty activating the thermodynamically stable CO_(2) molecules.Constructing plasmonic nanoalloy-based photocatalytic systems with significant localized surface plasmon resonance(LSPR)is full of po-tential but remains a vast challenge.In this work,AuAg plasmonic nanoalloys were incorporated on CeO_(2) nanorods(designated as AuAg–CeO_(2))to achieve selective photoreduction of CO_(2).The result displays that Ag can serve as a superior electron modifier to promote the electron enrichment of Au,thus producing asymmetric charge distributions to boost the selective conversion of CO_(2).Furthermore,the improved LSPR effect on AuAg–CeO_(2) induces the generation of high-energy hot electrons under irradiation,enhancing the reactivity of electrons for CO_(2) photo-reduction.Due to the aforementioned effects,AuAg–CeO_(2) exhibits a high CO_(2)-to-CH4 performance of 92.6μmol g-1 through a 3-h test and a high CH4 selectivity of 94.5%,up to 2.6,8.7,and 17.1 times higher than the activity of Au–CeO_(2),pure CeO_(2),and Ag–CeO_(2),respectively.This work can provide a new perspective for con-structing high-performance catalysts for photocatalytic CO_(2) reduction.
基金funding support from the National Key Research and Development Program of China(Nos.2022YFC2403501,2020YFA0210800)National Natural Science Foundation of China(No.22225401)+1 种基金Science and Technology Innovation Program of Hunan Province(No.2020RC4017)China Postdoctoral Science Foundation(No.2021M701145)。
文摘Plasmonic metal nanomaterials with intrinsic surface–enhanced Raman scattering(SERS)and photothermal properties,especially AuAg nanoalloys with both the outstanding merits of Au and Ag nanocrystals,show huge application prospects in bacterial theranostics.However,the direct exposure of AuAg nanoalloys in external conditions probably cause undesirable reactions and poisonous metal ion leakage during SERS detection and photothermal antibacterial therapy process,which severely hinder bacterial theranostics applications.Herein,we report an ultrastable graphene–isolated AuAg nanoalloy(GAA)with AuAg core confined in few–layer graphitic shell as a versatile platform for bacterial detection and therapy.The encapsulation of graphene ensures the good stability of AuAg core,that its superior SERS and photothermal properties are therefore further guaranteed.GAA is used for SERS detection of two vital bacterial biomarkers(including corrosive cyanide and pyocyanin),exhibiting good SERS quantitative and multiplexing ability.GAA is further used for photothermal antibacterial therapy application,and ultrahigh antibacterial efficacies for both Gram–negative Escherichia coli and Gram–positive Staphylococcus aureus are achieved under 808 nm laser irradiation.This work proposes a valuable method to develop robust bacterial theranostic platform.
文摘The mechanism of addition of separate atoms to a growing center is considered with application of model of a pair interpenetration of atoms. Features of geometrical model are related with the electronic structure of atoms and the Pauli＇s exclusion principle. The forces providing self-organization of atoms in the bulk of a condensed substance are shown. The calculated interatomic distances in graphite and alloys of gold with silver coincide with those known from experiments with accuracy of 0.1%.
