To mitigate the water pollution problem by photocatalytic degradation of typical antibiotics of tetracycline(TC),we prepared defective Bi_(2)Sn_(2)O_7(BSO)quantum dots(QDs)with a full spectral response due to Bi metal...To mitigate the water pollution problem by photocatalytic degradation of typical antibiotics of tetracycline(TC),we prepared defective Bi_(2)Sn_(2)O_7(BSO)quantum dots(QDs)with a full spectral response due to Bi metal deposition,using a one-pot hydrothermal method,labeled as Bi@BSO-OV.The optimized Bi@BSOOV showed 73.4% removal of TC in 1 h under irradiation with a 50 W LED lamp in the wavelength band in the visible-near-infrared(vis-NIR)light,a rate that is substantially greater than that of pure BSO(14.7%).The synergistic interaction of Bi metal and oxygen vacancies(OVs)is crucial to boosting photocatalytic performance.The near-infrared region of the photo-response is extended by the surface plasmon resonance(SPR)effect of Bi metal,enhancing the photocatalytic performance and dramatically raising the efficiency of solar energy utilization.In addition to inducing defect levels in BSO,the OVs also activate the surface adsorbed O_(2) to promote the production of·O_(2)^(-)and ^(1)O_(2).DFT calculations reveal that Bi metal and OVs can mutually tune the charge transfer pathways.On the one hand,Bi metal can act as both a charge transfer bridge and an electron donor to assist charge separation.On the other hand,OVs-induced defect levels allow electrons that leap to the conduction band(CB)to first leap from the valence band(VB)to the defect levels,notably improving interfacial charge separation and transfer.The concept of design executed in this study for altering the catalyst by introducing both OVs and Bi metal can provide a rational design idea and potential insight for improving the photocatalytic activity for environmental applications.展开更多
Accessing high-order multiphoton excited fluorescence(H-MPEF)materials is challenging yet and needs complicated synthesis procedures.In this study,we successfully assembled plasmonic Au nanorods(Au NRs)with multiphoto...Accessing high-order multiphoton excited fluorescence(H-MPEF)materials is challenging yet and needs complicated synthesis procedures.In this study,we successfully assembled plasmonic Au nanorods(Au NRs)with multiphoton responsive metalorganic frameworks(MOFs),resulting in a significant several-fold enhancement of H-MPEF.The extent of multiphoton enhancement was found to be strongly dependent on the degree of overlap between the multiphoton excitation wavelength of MOFs and the localized surface plasmon resonance absorbance of Au NRs,indicating the importance of plasmon-induced resonance energy transfer.Besides,plasmon-induced hot electron transfer played a vital role in enhanced multiphoton activity as well.Notably,the optimum H-MPEF enhancement occurs at the second near-infrared(NIR-II)region,which provides a promising platform for fluorescent bioimaging.Our findings provide a feasible and practical method to fabricate optimized H-MPEF materials for biological imaging using tissue-penetrating NIR-II light.展开更多
Atomically precise metal nanoclusters(NCs)have been deemed as an emerging class of metal nanomaterials owing to fascinating size-dependent physicochemical properties,discrete energy band structure,and quantum confinem...Atomically precise metal nanoclusters(NCs)have been deemed as an emerging class of metal nanomaterials owing to fascinating size-dependent physicochemical properties,discrete energy band structure,and quantum confinement effect,which are distinct from conventional metal nanoparticles(NPs).Nevertheless,metal NCs suffer from photoinduced self-oxidative aggregation accompanied by in-situ transformation to metal NPs,markedly reducing the photosensitization of metal NCs.Herein,maneuvering the generic instability of metal NCs,we perform the charge transport impetus comparison between atomically precise metal NCs and plasmonic metal NPs counterpart obtained from in-situ self-transformation of metal NCs in photoelectrochemical(PEC)water splitting reaction.For conceptual demonstration,we proposed two quintessential heterostructures,which include TNTAs-Au_(25)heterostructure fabricated by electrostatically depositing glutathione(GSH)-protected Au_(25)(GSH)_(18)NCs on the TiO_(2)nanotube arrays(TNTAs)substrate,and TNTAs-Au heterostructure constructed by triggering self-transformation of Au_(25)(GSH)_(18)NCs to plasmonic Au NPs in TNTAs-Au_(25)via calcination.The results indicate that photoelectrons produced over Au_(25)NCs are superior to hot electrons of plasmonic Au NPs in stimulating the interracial charge transport toward solar water oxidation.This is mainly ascribed to the significantly accelerated carrier transport kinetics,prolonged carrier lifespan,and substantial photosensitization effect of Au_(25)NCs compared with plasmonic Au NPs,resulting in the considerably enhanced PEC water splitting performance of TNTAs-Au_(25)relative to plasmonic TNTAs-Au counterpart under visible light irradiation.Our work would provide important implications for rationally designing atomically precise metal NCsbased photosystems toward solar energy conversion.展开更多
As a class of newly emerging functional material, Gallium based liquid metals have attracted increasing attentions in many fields, such as chip cooling, printed electronics and microfiuidics, etc. Particularly, the mo...As a class of newly emerging functional material, Gallium based liquid metals have attracted increasing attentions in many fields, such as chip cooling, printed electronics and microfiuidics, etc. Particularly, the motion control of liquid metal droplet has been recently tried for its importance in microelectromechanical system （MEMS）, microfluidics and potential use in micro-machine or reconfigurable soft robot. This paper is dedicated to explore the motion behavior of liquid metal droplet under AC electric field. The quickly induced oscillation phenomena of liquid metal droplet and surrounding electrolyte solution were observed and the major factors to influence such behaviors are theoretically interpreted and experimentally investigated, including the size of the liquid metal droplet, electrode voltage, electrolyte solution concentration and AC signal frequency etc. Moreover, some typical features to distinguish AC filed actuation with DC field are observed, such as intensive fluid waving induced by the resonance stimulation, and the efficient inhibition of solution electrolysis. Finally, two important applications of adopting AC induced surface oscillation of liquid metal droplet to develop solution mixer as well as fluidic pump were demonstrated which successfully avoid gas generation inside electrolyte environment. The bulk oscillation effects of liquid metal as clarified here could be very useful in a variety of areas such as solution disturbance and mixing, and fluid oscillator or pump etc.展开更多
The present work investigates the mechanically forced vibration of the hydro-elasto-piezoelectric system consisting of a two-layer plate“elastic+PZT”,a compressible viscous fluid,and a rigid wall.It is assumed that ...The present work investigates the mechanically forced vibration of the hydro-elasto-piezoelectric system consisting of a two-layer plate“elastic+PZT”,a compressible viscous fluid,and a rigid wall.It is assumed that the PZT(piezoelectric)layer of the plate is in contact with the fluid and time-harmonic linear forces act on the free surface of the elastic-metallic layer.This study is valuable because it considers for the first time the mechanical vibration of the metal+piezoelectric bilayer plate in contact with a fluid.It is also the first time that the influence of the volumetric concentration of the constituents on the vibration of the hydro-elasto-piezoelectric system is studied.Another value of the present work is the use of the exact equations and relations of elasto-electrodynamics for elastic and piezoelectric materials to describe the motion of the plate layers within the framework of the piecewise homogeneous body model and the use of the linearized Navier-Stokes equations to describe the flow of the compressible viscous fluid.The plane-strain state in the plate and the plane flow in the fluid take place.For the solution of the corresponding boundary-value problem,the Fourier transform is used with respect to the spatial coordinate on the axis along the laying direction of the plate.The analytical expressions of the Fourier transform of all the sought values of each component of the system are determined.The origins of the searched values are determined numerically,after which numerical results on the stress on the fluid and plate interface planes are presented and discussed.These results are obtained for the case where PZT-2 is chosen as the piezoelectric material,steel and aluminum as the elastic metal materials,and Glycerin as the fluid.Analysis of these results allows conclusions to be drawn about the character of the problem parameters on the frequency response of the interfacial stress.In particular,it was found that after a certain value of the vibration frequency,the presence of the metal laye展开更多
Designing low-cost and high-performance photoelectrodes with improved light harvesting and charge separation rates is significant in photoelectrochemical water splitting.Here,a novel TiO2/Cu2O/Al/Al2O3 photoelectrode ...Designing low-cost and high-performance photoelectrodes with improved light harvesting and charge separation rates is significant in photoelectrochemical water splitting.Here,a novel TiO2/Cu2O/Al/Al2O3 photoelectrode is manufactured by depositing plasmonic nanoparticles of the non-noble metal Al on the surface of a TiO2/Cu2O core/shell heterojunction for the first time.The Al nanoparticles,which exhibit a surface plasmon resonance(SPR)effect and are substantially less expensive than noble metals such as Au and Ag,generate hot electron-hole pairs and amplify the electromagnetic field at the interface under illumination.The as-prepared TiO2/Cu2O/Al/Al2O3 photoelectrodes have an extended absorption range and enhanced carrier separation and transfer.Their photocurrent density of 4.52 mA·cm^-2 at 1.23 V vs.RHE represents an 1.84-fold improvement over that of TiO2/Cu2O.Specifically,the ultrathin Al2O3 passivation layer spontaneously generated on the surface of Al in air could act as a protective layer to significantly increase its stability.In this work,the synergistic effect of the heterojunctions and the SPR effect of the non-noble metal Al significantly improve the photoelectrode performance,providing a novel concept for the design of electrodes with good properties and high practicability.展开更多
Noble metal nanostructures possess novel optical properties because of their collective electronic oscillations, known as sur- face plasmons （SPs）. The resonance of SPs strongly depends on the material, surrounding ...Noble metal nanostructures possess novel optical properties because of their collective electronic oscillations, known as sur- face plasmons （SPs）. The resonance of SPs strongly depends on the material, surrounding environment, as well as the geome- try of the nanostructures. Complex metal nanostructures have attracted research interest because of the degree of freedom in tailoring the plasmonic properties for more advanced applications that are unattainable by simple ones. In this review, we dis- cuss the plasmonic properties of several typical types of complex metal nanostructures, that is, electromagnefically coupled nanoparticles （NPs）, NPs/metal films, NPs/nanowires （NWs）, NWs/NWs, and metal nanostructures supported or coated by di- electrics. The electromagnetic field enhancement and surface-enhanced Raman scattering applications are mainly discussed in the NPs systems where localized SPs have a key role. Propagating surface plasmon polaritons and relevant applications in plasmonic routers and logic gates using NWs network are also reviewed. The effect of dielectric substrates and surroundings of metal nanostructures to the plasmonic properties is also discussed.展开更多
Crystalline TiO（P25） and isolated titanate species in a ZSM-5 structure（TS-1） were modified with Au and Ag, respectively, and tested in the gas-phase photocatalytic COreduction under high purity conditions. The no...Crystalline TiO（P25） and isolated titanate species in a ZSM-5 structure（TS-1） were modified with Au and Ag, respectively, and tested in the gas-phase photocatalytic COreduction under high purity conditions. The noble metal modification was performed by photodeposition. Light absorbance properties of the catalysts are examined with UV–Vis spectroscopy before and after the activity test. In the gas-phase photocatalytic COreduction, it was observed that the catalysts with Ag nanostructures are more active than those with Au nanostructures. It is thus found that the energetic difference between the band gap energy of the semiconductor and the position of the plasmon is influencing the photocatalytic activity.Potentially, plasmon excitation due to visible light absorption results in plasmon resonance energy, which affects the excitation of the semiconductor positively. Therefore, an overlap between band gap energy of the semiconductor and metal plasmon is needed.展开更多
Uniform flower-like TiO2 coated Au nanostars and core-shell Au@Ag nanostars with different amounts of Ag coating were prepared through a facile method by hydrolysis of TiF4 under an acidic environment. The photocataly...Uniform flower-like TiO2 coated Au nanostars and core-shell Au@Ag nanostars with different amounts of Ag coating were prepared through a facile method by hydrolysis of TiF4 under an acidic environment. The photocatalytic capability of these flower-like nanocomposites under visible light irradiation was found to be enhanced by up to 4.7-fold compared to commercial P25 TiO2 nanoparticles. The enhanced photocatalytic activity was ascribed to improved light absorption and hot electron inj ection from the photo-excited Au@Ag core to the TiO2 shell.展开更多
基金financially supported by the Key Project of Natural Science Foundation of Tianjin(No.21JCZDJC00320)National Key R&D Program International Cooperation Project(No.2021YFE0106500)+1 种基金Tianjin Development Program for Innovation and EntrepreneurshipFundamental Research Funds for the Central Universities,Nankai University。
文摘To mitigate the water pollution problem by photocatalytic degradation of typical antibiotics of tetracycline(TC),we prepared defective Bi_(2)Sn_(2)O_7(BSO)quantum dots(QDs)with a full spectral response due to Bi metal deposition,using a one-pot hydrothermal method,labeled as Bi@BSO-OV.The optimized Bi@BSOOV showed 73.4% removal of TC in 1 h under irradiation with a 50 W LED lamp in the wavelength band in the visible-near-infrared(vis-NIR)light,a rate that is substantially greater than that of pure BSO(14.7%).The synergistic interaction of Bi metal and oxygen vacancies(OVs)is crucial to boosting photocatalytic performance.The near-infrared region of the photo-response is extended by the surface plasmon resonance(SPR)effect of Bi metal,enhancing the photocatalytic performance and dramatically raising the efficiency of solar energy utilization.In addition to inducing defect levels in BSO,the OVs also activate the surface adsorbed O_(2) to promote the production of·O_(2)^(-)and ^(1)O_(2).DFT calculations reveal that Bi metal and OVs can mutually tune the charge transfer pathways.On the one hand,Bi metal can act as both a charge transfer bridge and an electron donor to assist charge separation.On the other hand,OVs-induced defect levels allow electrons that leap to the conduction band(CB)to first leap from the valence band(VB)to the defect levels,notably improving interfacial charge separation and transfer.The concept of design executed in this study for altering the catalyst by introducing both OVs and Bi metal can provide a rational design idea and potential insight for improving the photocatalytic activity for environmental applications.
基金supported by a grant for the National Natural Science Foundation of China(Nos.22171001 and 22305001)Natural Science Foundation of Anhui Province(No.2108085MB49)the Institutional Animal Care and Use Committee of Anhui University(serial number:2021-015)based on the National Standard of China GB/T35892-2018 guidelines for Ethical Review of Experimental Animal Welfare.
文摘Accessing high-order multiphoton excited fluorescence(H-MPEF)materials is challenging yet and needs complicated synthesis procedures.In this study,we successfully assembled plasmonic Au nanorods(Au NRs)with multiphoton responsive metalorganic frameworks(MOFs),resulting in a significant several-fold enhancement of H-MPEF.The extent of multiphoton enhancement was found to be strongly dependent on the degree of overlap between the multiphoton excitation wavelength of MOFs and the localized surface plasmon resonance absorbance of Au NRs,indicating the importance of plasmon-induced resonance energy transfer.Besides,plasmon-induced hot electron transfer played a vital role in enhanced multiphoton activity as well.Notably,the optimum H-MPEF enhancement occurs at the second near-infrared(NIR-II)region,which provides a promising platform for fluorescent bioimaging.Our findings provide a feasible and practical method to fabricate optimized H-MPEF materials for biological imaging using tissue-penetrating NIR-II light.
基金support by the Award Program for Minjiang Scholar Professorshipfinancially supported by the National Natural Science Foundation of China(Nos.21703038,22072025)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(No.2021ZR147)。
文摘Atomically precise metal nanoclusters(NCs)have been deemed as an emerging class of metal nanomaterials owing to fascinating size-dependent physicochemical properties,discrete energy band structure,and quantum confinement effect,which are distinct from conventional metal nanoparticles(NPs).Nevertheless,metal NCs suffer from photoinduced self-oxidative aggregation accompanied by in-situ transformation to metal NPs,markedly reducing the photosensitization of metal NCs.Herein,maneuvering the generic instability of metal NCs,we perform the charge transport impetus comparison between atomically precise metal NCs and plasmonic metal NPs counterpart obtained from in-situ self-transformation of metal NCs in photoelectrochemical(PEC)water splitting reaction.For conceptual demonstration,we proposed two quintessential heterostructures,which include TNTAs-Au_(25)heterostructure fabricated by electrostatically depositing glutathione(GSH)-protected Au_(25)(GSH)_(18)NCs on the TiO_(2)nanotube arrays(TNTAs)substrate,and TNTAs-Au heterostructure constructed by triggering self-transformation of Au_(25)(GSH)_(18)NCs to plasmonic Au NPs in TNTAs-Au_(25)via calcination.The results indicate that photoelectrons produced over Au_(25)NCs are superior to hot electrons of plasmonic Au NPs in stimulating the interracial charge transport toward solar water oxidation.This is mainly ascribed to the significantly accelerated carrier transport kinetics,prolonged carrier lifespan,and substantial photosensitization effect of Au_(25)NCs compared with plasmonic Au NPs,resulting in the considerably enhanced PEC water splitting performance of TNTAs-Au_(25)relative to plasmonic TNTAs-Au counterpart under visible light irradiation.Our work would provide important implications for rationally designing atomically precise metal NCsbased photosystems toward solar energy conversion.
基金partially supported by the Dean’s Research Funding of the Chinese Academy of Sciences and Beijing Municipal Science and Technology Project(Grant No.Z141100000514005)
文摘As a class of newly emerging functional material, Gallium based liquid metals have attracted increasing attentions in many fields, such as chip cooling, printed electronics and microfiuidics, etc. Particularly, the motion control of liquid metal droplet has been recently tried for its importance in microelectromechanical system （MEMS）, microfluidics and potential use in micro-machine or reconfigurable soft robot. This paper is dedicated to explore the motion behavior of liquid metal droplet under AC electric field. The quickly induced oscillation phenomena of liquid metal droplet and surrounding electrolyte solution were observed and the major factors to influence such behaviors are theoretically interpreted and experimentally investigated, including the size of the liquid metal droplet, electrode voltage, electrolyte solution concentration and AC signal frequency etc. Moreover, some typical features to distinguish AC filed actuation with DC field are observed, such as intensive fluid waving induced by the resonance stimulation, and the efficient inhibition of solution electrolysis. Finally, two important applications of adopting AC induced surface oscillation of liquid metal droplet to develop solution mixer as well as fluidic pump were demonstrated which successfully avoid gas generation inside electrolyte environment. The bulk oscillation effects of liquid metal as clarified here could be very useful in a variety of areas such as solution disturbance and mixing, and fluid oscillator or pump etc.
文摘The present work investigates the mechanically forced vibration of the hydro-elasto-piezoelectric system consisting of a two-layer plate“elastic+PZT”,a compressible viscous fluid,and a rigid wall.It is assumed that the PZT(piezoelectric)layer of the plate is in contact with the fluid and time-harmonic linear forces act on the free surface of the elastic-metallic layer.This study is valuable because it considers for the first time the mechanical vibration of the metal+piezoelectric bilayer plate in contact with a fluid.It is also the first time that the influence of the volumetric concentration of the constituents on the vibration of the hydro-elasto-piezoelectric system is studied.Another value of the present work is the use of the exact equations and relations of elasto-electrodynamics for elastic and piezoelectric materials to describe the motion of the plate layers within the framework of the piecewise homogeneous body model and the use of the linearized Navier-Stokes equations to describe the flow of the compressible viscous fluid.The plane-strain state in the plate and the plane flow in the fluid take place.For the solution of the corresponding boundary-value problem,the Fourier transform is used with respect to the spatial coordinate on the axis along the laying direction of the plate.The analytical expressions of the Fourier transform of all the sought values of each component of the system are determined.The origins of the searched values are determined numerically,after which numerical results on the stress on the fluid and plate interface planes are presented and discussed.These results are obtained for the case where PZT-2 is chosen as the piezoelectric material,steel and aluminum as the elastic metal materials,and Glycerin as the fluid.Analysis of these results allows conclusions to be drawn about the character of the problem parameters on the frequency response of the interfacial stress.In particular,it was found that after a certain value of the vibration frequency,the presence of the metal laye
文摘Designing low-cost and high-performance photoelectrodes with improved light harvesting and charge separation rates is significant in photoelectrochemical water splitting.Here,a novel TiO2/Cu2O/Al/Al2O3 photoelectrode is manufactured by depositing plasmonic nanoparticles of the non-noble metal Al on the surface of a TiO2/Cu2O core/shell heterojunction for the first time.The Al nanoparticles,which exhibit a surface plasmon resonance(SPR)effect and are substantially less expensive than noble metals such as Au and Ag,generate hot electron-hole pairs and amplify the electromagnetic field at the interface under illumination.The as-prepared TiO2/Cu2O/Al/Al2O3 photoelectrodes have an extended absorption range and enhanced carrier separation and transfer.Their photocurrent density of 4.52 mA·cm^-2 at 1.23 V vs.RHE represents an 1.84-fold improvement over that of TiO2/Cu2O.Specifically,the ultrathin Al2O3 passivation layer spontaneously generated on the surface of Al in air could act as a protective layer to significantly increase its stability.In this work,the synergistic effect of the heterojunctions and the SPR effect of the non-noble metal Al significantly improve the photoelectrode performance,providing a novel concept for the design of electrodes with good properties and high practicability.
基金supported by the Ministry of Science and Technology of China(Grant Nos.2009CB930700 and 2012YQ12006005)the National Natural Science Foundation of China(Grant Nos.11134013 and11227407)the Knowledge Innovative Program of the Chinese Academy of Sciences(Grant No.KJCX2-EW-W04)
文摘Noble metal nanostructures possess novel optical properties because of their collective electronic oscillations, known as sur- face plasmons （SPs）. The resonance of SPs strongly depends on the material, surrounding environment, as well as the geome- try of the nanostructures. Complex metal nanostructures have attracted research interest because of the degree of freedom in tailoring the plasmonic properties for more advanced applications that are unattainable by simple ones. In this review, we dis- cuss the plasmonic properties of several typical types of complex metal nanostructures, that is, electromagnefically coupled nanoparticles （NPs）, NPs/metal films, NPs/nanowires （NWs）, NWs/NWs, and metal nanostructures supported or coated by di- electrics. The electromagnetic field enhancement and surface-enhanced Raman scattering applications are mainly discussed in the NPs systems where localized SPs have a key role. Propagating surface plasmon polaritons and relevant applications in plasmonic routers and logic gates using NWs network are also reviewed. The effect of dielectric substrates and surroundings of metal nanostructures to the plasmonic properties is also discussed.
文摘Crystalline TiO（P25） and isolated titanate species in a ZSM-5 structure（TS-1） were modified with Au and Ag, respectively, and tested in the gas-phase photocatalytic COreduction under high purity conditions. The noble metal modification was performed by photodeposition. Light absorbance properties of the catalysts are examined with UV–Vis spectroscopy before and after the activity test. In the gas-phase photocatalytic COreduction, it was observed that the catalysts with Ag nanostructures are more active than those with Au nanostructures. It is thus found that the energetic difference between the band gap energy of the semiconductor and the position of the plasmon is influencing the photocatalytic activity.Potentially, plasmon excitation due to visible light absorption results in plasmon resonance energy, which affects the excitation of the semiconductor positively. Therefore, an overlap between band gap energy of the semiconductor and metal plasmon is needed.
基金supportedby the Ministry of Education of Singapore(R-143-000-607-112)the National Natural Science Foundation of China(21673155)
文摘Uniform flower-like TiO2 coated Au nanostars and core-shell Au@Ag nanostars with different amounts of Ag coating were prepared through a facile method by hydrolysis of TiF4 under an acidic environment. The photocatalytic capability of these flower-like nanocomposites under visible light irradiation was found to be enhanced by up to 4.7-fold compared to commercial P25 TiO2 nanoparticles. The enhanced photocatalytic activity was ascribed to improved light absorption and hot electron inj ection from the photo-excited Au@Ag core to the TiO2 shell.
