Plasmonic Photothermal Regulation And Catalysis On The Surface Of Gold Particles

Surface plasmons is a collective coherent oscillation of free electrons on the metal surface,which can break the diffraction limit and realize the localization of the light field at the nanometer scale.Localized surface plasmons resonance is a resonance mode caused by the interaction of free electrons and light field on the surface of metal nanoparticles,which can significantly enhance the absorption efficiency of light and form an instantaneous high electron density on the surface,and Enhanced the local electromagnetic field.Plasmons is radiated by coherent photons,or through electron-electron and phonon interaction,dissipating energy into the metal lattice in the form of heat,and quickly heating the particle itself and the medium around the particle,which is called photothermal effect.Using metal nanoparticles,a nanoscale heat source with fast time response,high local temperature,and strong controllability,the photothermal effect has been widely used for photothermal catalytic molecular reactions,photothermal therapy,photothermal imaging,and desalination of seawater,etc.In this paper,we combine theoretical calculations and experimental measurements to study the photothermal regulation and photocatalytic application of gold nanoparticles,and clarify the influence factors and physical mechanism of heat production and heat transfer.It provides reference value for the precise control of the photothermal effect of plasmon,as well as the experimental design and theoretical research of plasmon catalysis.The main research contents are as follows:1.Study the photothermal effect of gold nanoparticles under different conditions,including the effect of particle size on photothermal effect,the effect of medium environment on photothermal effect,the photothermal effect of dimer.It was found that the photothermal effect of gold nanoparticles can be adjusted in many ways,and the influence of the medium environment on local temperature is very large.2.Studied the structural transformation of gold nanoparticle plasmon photothermal catalytic rare earth nanocrystals,combined with theoretical calculations,we found that the plasmon photocatalytic reaction is affected by many aspects,among which the photothermal effect and hot electron catalytic effect are often simultaneously exist.By adjusting the wavelength of excitation light,the contribution of these two effects to the reaction can be controlled to achieve the best catalytic effect.