Study On The Selective Catalytic Reaction Mechanism Of Silver Particle Film By Surface-enhanced Raman Spectroscopy

Silver nanoparticle film,which has the characteristics of plasmon resonance and can induce photocatalytic reaction,is commonly used as photocatalytic materials.However,the photogenerated electrons and holes of nano-Ag are easy to recombine,and their photocatalytic performance is limited.In this paper,three methods were used to improve the photocatalytic performance of silver nanoparticle films,including oxidation treatment,nano-copper composite,and nano-titanium dioxide composite.Surface-enhanced Raman spectroscopy was used to monitor the catalytic reaction in situ.Around this theme,this paper carries out the following work:In this paper,nano Ag particle films were oxidized by plasma irradiation and annealing in oxygen atmosphere to test their catalytic oxidation performance for PATP.The results show that the catalytic performance of nano Ag particle films after oxidation treatment has been significantly improved,but the catalytic mechanism is different.Electrophilic oxygen?O^-?is produced after plasma irradiation,which improves the catalytic performance.Superoxide ion?O₂^-?is produced after oxygen annealing,which improves the catalytic performance.The catalytic reduction of PNTP by Ag nano particle film and Cu nano particle film was tested.Composite films with nano Ag/Cu and nano Cu/Ag configurations were prepared by adjusting the evaporation sequence of nano Ag and nano Cu.The results show that the photocatalytic performance of nano Ag/Cu composite films is significantly improved compared with that of single-layer nano Ag films,while the photocatalytic performance of nano Cu/Ag composite films is not significantly improved.We believe that the catalytic mechanism may be related to the charge transfer caused by the interaction between nano Cu and nano Ag.The catalytic performance of nano-Ag granular film and titanium dioxide film on R6G was tested.On the basis of xTiO₂-30sAgNPs configuration and 30sAgNPs-xTiO₂configuration,we proposed 100sTiO₂-30sAgNPs-xTiO₂"sandwich"configuration composite films.The results show that the photocatalytic degradation value of100sTiO₂-30sAgNPs-xTiO₂ reaches the maximum when the thickness of top TiO₂ is2nm,and the cycling efficiency of carriers reaches the maximum.This research is of scientific significance for further understanding the catalytic mechanism of silver nanoparticle membranes in selective catalytic reactions.At the same time,it also provides a new idea for further improving the catalytic performance of silver nanoparticles.