Preparation And Photothermal Properties Of Ag And Its Compounds Nanomaterials

Silver-based nano-composites have drawn much attention in the field of phototermal therapy because of their excellent optical absorption and photothermal conversion properties.In this thesis,Ag@Ag₂S core@shell structures,Ag₂S/Ag heterostructures,and Blue Silver complex were synthesized.The samples were characterized by XRD,SEM,TEM,and so on.The optical absorption properties and photothermal conversion properties of samples were tested and the photothermal conversion efficiency of samples was calculated.The results are as follows:1.Octopod-like Ag@Ag₂S core@shell structures and spherical-like Ag@Ag₂S core@shell structures were synthesized with Ag nanocubes and spherical-like Ag nanoparticles as templates.In comparison to the Ag nanoparticles,both the octopod-like and the spherical-like Ag@Ag₂S core@shell structures exhibited broader absorption spectra and higher absorbance from visible to infrared regions.The photothermal conversion property and the photothermal conversion efficiency of samples were tested and calculated.Under the irradiation of 808 nm laser,the maximum temperature elevations of the octopod-like Ag@Ag₂S and spherical-like Ag@Ag₂S were 35 oC and 38 oC at a mass fraction of 0.01%.The photothermal conversion efficiencies of the above samples were 58.56% and 63.07% respectively.The results showed that the octopod-like Ag@Ag₂S and spherical-like Ag@Ag₂S exhibited enhanced photothermal conversion property in comparison to Ag nanoparticles and Ag2 S nanoparticles.2.Ag₂S/Ag heterostructures were synthesized through in-site redution of Ag2 S nanoparticles.An absorption peak at 400 nm appeared in spectrum of the Ag₂S/Ag heterostructures and the absorbance of the Ag₂S/Ag heterostructures was enhanced compared to that of the Ag2 S nanoparticles in the near infrared region.Under the irradiation of 808 nm laser,the maximum temperature elevation and photothermal conversion efficiency of the Ag₂S/Ag heterostructures were 17.2 oC and 51.27% at a mass fraction of 0.01%.Ag₂S/Ag heterostructures exhibited enhanced photothermal conversion property compared to Ag2 S nanoparticles.3.Blue Silver complex was synthesized by mixing AgNO₃ aqueous solution with P30 aqueous solution.The optical absorption property and photothermal conversion property of the complex were tested and the photothermal conversion efficiency was calculated.The results show that the Blue Silver complex exhibits a strong absorption peak at 600-900 nm.Under the irradiation of 808 nm laser,the maximum temperature elevation varied from 14.6 oC to 48.9 oC with the mass fraction varied from 0.005% to 0.05%.The maximum photothermal conversion efficiency is 68.79% at a mass fraction of 0.03%.