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Preparation Of Copper Micro-nano Composite Structures And Research On The Properties Of Surface-enhanced Raman Substrates

Posted on:2022-05-02Degree:MasterType:Thesis
Country:ChinaCandidate:J B HuangFull Text:PDF
GTID:2511306341999989Subject:Material Science
Abstract/Summary:PDF Full Text Request
Surface enhanced Raman scattering(SERS)is a trace detection technology based on the strong local electric field on the surface of nanostructures to expand the Raman signal.Because of its high detection sensitivity and fast detection process,it can achieve nondestructive detection in many fields,such as environmental monitoring,biomedicine,food health care and so on.SERS substrate is the basis of SERS detection technology.In recent years,ordered metal micro nano composite substrate has become a new type of SERS material.Compared with the single channel nanostructure,this structure has more dense "hot spots" and larger specific surface area,which can improve the adsorption capacity of the measured molecules per unit area,and has a very strong application prospect of SERS.However,the fabrication of this structure often requires complex equipment and expensive production cost.In order to solve these problems,we have developed a highly ordered alumina nano cone hole nested micro bowl structure by ourselves.Using this structure as a sacrificial template,we have successfully prepared the copper nanorod nested micro sphere composite structure by template deposition method,gold nanoparticles were deposited on the surface by ion sputtering technology.The morphology and gap size of copper micro nano composite structure were adjusted by adjusting the spraying time.The SERS active substrate was used to detect the Raman enhancement performance.The specific research contents are as follows:(1)Preparation of micro nano composite structure of copper by template deposition.Firstly,the controllable preparation of alumina micro nano composite template was realized by high voltage anodization,mild preoxidation,multi-step mild oxidation and pore expansion technology.Then,the copper nanorod nested microsphere composite structure was successfully obtained by simple template electrodeposition technology.The SEM morphology test results show that the prepared copper micro nano composite structure and alumina template are highly ordered and have one morphology cycle The XRD results show that the surface of the copper structure is poly crystal line rather than monocrystalline,and there are mixed phases of Cu,CuO and Cu2O.XPS analysis shows that the surface of the copper structure contains Cu,C and O,and contains Cu2+and Cu1+,which is consistent with the XRD results,because the surface of the copper is oxidized and doped with a small amount of oxides.Then,the deposition mechanism of Cu micro unit structure and Cu nano unit structure was studied.It was found that the nanorod structure of Cu micro nano composite structure was hollow and the microsphere structure was solid.It is proved that it is feasible to prepare micro nano composite copper surface by template electrodeposition technology,which is of great significance for the preparation of multi-dimensional metal micro nano composite structure by template deposition method.(2)Surface enhanced Raman properties of copper micro nano composite substrate.high purity gold films were deposited on copper micro nano composite structure by ion sputtering,Six groups of samples with different spraying time were characterized by SEM and detected by SERS.The samples with spraying time of 0 s,10 s and 20 s had better morphology stability and uniformity,and the spraying time of 40 s,60 s and 80 s,The six groups of samples were immersed in 10-6 M R6G solution for chemical modification for 8 h,and the SERS signal was detected.The time of spraying gold was 20 h Subsequently,Then the stability of the sample was further studied,and the SERS signals of 40 groups of samples from three different batches were randomly collected for horizontal comparison.The results showed that five characteristic peaks were 609 cm-1,772 cm-1,1358 cm-1,1506 cm-1 and 1650 cm-1 The relative standard deviations(RSD)of the samples were 11.2%,10.3%,8.9%,11.2%and 9.4%.In order to obtain statistically significant results,The enhancement factor of the sample with 20 s spraying time is 0.95×107(1358 cm-1).It is proved that the copper micro nano composite structure substrate of the composite gold film has excellent Raman enhancement performance.
Keywords/Search Tags:Copper micro nano composite structure, Porous anodic alumina template, Electrochemical deposition technology, Surface-enhanced Raman spectroscopy
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