Construction Of Plug And Play Composites Containing Silver Nanoparticles With Different Morphologies Regulated By Conducting Polymer Compounds And Their SERS And Catalytic Degradation Properties

With the rapid development of textile and pharmaceutical industry,some carcinogenicantibiotics,organic dyes and other pollutants are discharged into the water,which poses a great threat to the environment and human health.Therefore,it is of great significance to develop technologies and related functional materials that can realize efficient detection and catalytic degradation of organic pollutants in wastewater.Surface enhanced Raman spectroscopy(SERS)and chemical catalytic degradation technology are important means to solve the above problems,among which the key is to design and construct functional materials with excellent Raman and catalytic activities.Noble metal Ag is easy to produce local surface plasmon resonance(LSPR)effect,and thus the SERS activity and low Fermi level are enhanced.Its electron transfer performance can be improved by regulating particle size and morphology.Conductive polymers are stable and easy to be synthesized,which are important candidates for regulating the morphology and properties of nanoparticles.Based on this,the morphology of Ag NPs was regulated by Polyaniline(PANI),Graphene oxide(GO)and Poly pyrrole(PPY)with electrochemical method.A variety of plug-and-play nanocomposites contained Ag NPs with good dispersion,diverse morphology and low cost were constructed,the SERS and catalytic degradation properties of nanocomposites for organic pollutants in water were further studied.The main research contents are as follows:By the induction of the polyaniline(PANI)on copper sheet,special Ag nanoparticles with uniform distribution and dendritic morphologywere facilely synthesized by electrochemical deposition.Monitored by scanning electron microscope,the important function of the PANI in the growth of Ag particles was demonstrated.The obtained Cu/PANI/Ag sheet was plug-and-play,and can beacted as surface enhanced Raman scattering(SERS)substrate for sensitive detection of malachite green(MG,a kind of carcinogenic compound commonly used in aquaculture).The SERS signals detected were increased monotonically with the increase of MG concentration,which was consistent with Langmuir model,indicating the presence of chemical adsorption.It was found that a large number of homogeneous and highly dispersed "hot spots" produced by the dentritic Ag and the formed N-Ag bond were conducive to the detection of trace MG.Subsequently,as low as 1×10-11 M MG can be sensitively detected by the Cu/PANI/Ag sheet,and analysis enhancement factor(AEF)was 5.64×107.Furthermore,the MG in real water can be detected by the Cu/PANI/Ag sheet,and it was more sensitive,stable and cost-effective compared with some traditional substrates.It is potential in designing sensitive SERS sensors for toxicant detection in practical application.Secondly,the "micron flower"-like morphology of Graphene oxide-Polypyrrole(GO-PPY)(GO-PPY)nanocomposite structure was constructed on the Cu sheet,and it was used as a soft template to control the morphology and growth of Ag nanoparticles,and a kind of the nanocomposite material containing the dense "skeletal" morphology of Ag NPs was constructed.In the presence of NaBH4,it showed efficient catalytic degradation of rhodamine B(RhB,3×10-5 M)(almost 100%degradation in 5 min)and degradation cycle stability.Compared with some traditional substrates,Cu/GO/PPY/Ag has a broad spectrum in SERS detection,which can effectively identify and detect a variety of organic dyes such as methyl orange,methylene blue and phenol red.The surface electromagnetic field of Cu/GO/PPY/Ag composites was simulated and analyzed by finite difference time domain(FDTD)technology,and the possible SERS enhancement and catalytic degradation mechanisms were proposed combined with free radical trapping experiment.Finally,the Cu/GO/PPY/Cu/Ag nanocomposite with "popcorn" Cu-Ag BNP was constructed by introducing Cu-Ag bimetallic nanoparticles(BNP)on a Cu plate loaded with GO-PPY nanocomposite structure through in-situ reduction.Furthermore,the SERS and catalytic degradation performance of RhB and the catalytic degradation activity and stability of the pharmaceutical antibiotic tetracycline(TCH)by Cu/GO/PPY/Cu/Ag nanocomposites were researched.The results showed that,compared with Cu/GO/PPY/Ag,the Cu/GO/PPY/Cu/Ag possessed higher SERS activity and catalytic degradation activity.Mechanism studies showed that the exposure of special crystal surface(004)of metal Ag induced by the synergistic resonance coupling effect between bimetals,the high efficiency of pollutant molecule enrichment,and the generations of more "hot spot" and "popcorn"morphology are the main reasons for the enhancement of its activity.In this paper,a variety of plug and play nanocomposites were constructed by using conductive macromolecules to regulate the growth of silver nanoparticles with different morphologies.The SERS performance and catalytic degradation performance of the prepared nanocomposites for organic pollutants in water were researched,and the mechanisms for improving their SERS and catalytic degradation activity were further discussed.It provides a new idea for the design and preparation of other bi-functional materials in the detection and degradation of organic pollutants in wastewater,and also provides theoretical and experimental basis for the practical application of the detection and degradation of organic pollutants in wastewater.