| With the intensification of the energy crisis and environmental pollution,people have been paying close attention to the harvest and conversion of solar energy.In recent years,composite nanomaterials composed of semiconductor materials and plasmon metal nanoparticles(NP)have been recognized as high-efficiency light energy conversion materials in the fields of photo-electronic and biomedical research.Inorganic semiconductor materials themselves have special optical and catalytic properties,and metal nanoparticles(such as Au,Ag,Cu)under light excitation can trigger a unique Surface Plasmon Resonance(SPR)effect.However,how to rationally construct a plasmonic nanohybrid structure to obtain better photocatalysis and photothermal conversion performance is still an urgent problem to be solved.In this paper,starting from the enhancement of SPR scattering,photon absorption and near-field enhancement,several novel noble metal/semiconductor plasmonic nanocomposites were innovatively designed and prepared,and their morphology,structure,physical and chemical properties,photoelectric properties and photothermal conversion performance were studied by a series of characterization and testing methods.Finally,through element simulation simulation calculations and experimental verification,the structure-activity relationship between the enhanced SPR light response of plasmon composites and its structural parameters,and the mechanism of SPR effect in the application of photocatalysis and photothermal therapy.(1)Design and synthesis of Ag multi@Ce O2-Au scattering-enhanced plasmonic core@shell nanostructure to improve photocatalytic performance effectively:Great efforts have been devoted to increase the intrinsic absorptivity of the photocatalytic materials;however,the possible contribution of SPR scattering to photocatalysis has been long time overlooked.Here,a versatile strategy was provided to promote the light absorption of photocatalytic systems using SPR scattering enhancement.On the basis of preliminary simulation calculations,Ag NP was integrated into the Au-Ce O2 system as the scattering core,and the Ag@Ce O2-Au nanostructure was designed and prepared.In this hybrid nanostructure,the SPR of Ag core afforded a dual function to as a scatteror to greatly augment SPR excitation of Au NPs and as SPR resonator to enhance the near field at the Au-Ce O2 interface,which ultimately increases the photocatalytic efficiency of Au-Ce O2 system for organic conversion.By manipulating the size and aggregation state of Ag NP core,intense SPR scattering can be obtained over visible to NIR spectral region.In addition,the scattering of Ag multimer core and the SPR absorption of Au nanorods(NR)exhibited obvious optical coupling,which greatly enhances the light response activity of Ag multimer@Ce O2-Au NRs and broadens the light absorption region to the near infrared region(NIR).The photocatalytic tests show that the Ag multimer@Ce O2-Au NRs nanostructure exhibits excellent photocatalytic organic conversion efficiency and degradation performance of toxic pollutants.A large number of finite element method numerical simulation calculations have also verified the effective role of Ag multimer core SPR scattering and Au NRs SPR absorption in promoting photon absorption and near-field enhancement,completing the structure of Ag multimer@Ce O2-Au NRs Mechanism analysis of high photocatalytic performance.Many numerical simulations verify that the SPR scattering of Ag multimer core and the SPR absorption of Au NRs have a synergistic effect,resulting in high photocatalytic performance of Ag multimer@Ce O2-Au NRs.(2)Design and synthesis of Au Cu star/Cu2-xSx dual plasmonic nano-core-shell composite structure for tumor photothermal treatment:Au and Cu2-xSx are classic plasmon NPs to convert NIR photons into local heat for photothermal therapy.The rational construction of Au/Cu2-xSx nanohybrids is expected to couple both SPR effects for better photothermal converting property;however,the construction such hybrids via wet-chemistry method with a well-controlled inter-facial structure is still challengeable.Here,we reported the synthesis of a Au Cu star/Cu2-xSx plasmonic nanohybrid structure,where the Cu2-xSx components are anisotropically grown on the tips of the metallic Au Cu nanostar to form“caps”.We found that the spatial for-mation of the Cu2-xSx caps on star tips is mainly governed by concentration of surfactant as well as the curvature of tip.The Star/Cu2-xSx nanohybrids show low cytotoxicity and enhanced photothermal conversion efficiency,enabling them to kill cancer cells in the second NIR window with low nanomaterial dose and laser flux.Numerical simulation reveals the coupling of Cu2-xSx on nanostar tips generates strong interfacial electric field,leading to the enhanced photothermal converting performance.Moreover,the spatial separation structure favors the continuous flow of hot charge carriers for surface reaction to produce highly active radicals during the process,further promoting the effect of tumor treatment. |
PDF Full Text Request