| Since the discovery of surface-enhanced Raman phenomenon(SERS),passion of related research never decreased,and various substrate materials have been prepared.Among which using composite nanoarray for SERS detection analysis is still a "hot-topic" research direction,and it is easy to application.In this thesis,Ag/TiO2 composite nanoarray materials were mainly discussed.By controlling the hydrothermal reaction conditions,TiO2 nanoarrays with different morphology and in-situ growth were obtained.Ag/TiO2 nanometer array was produced by adjusting the magnetron sputtering conditions.By simplifying the synthesis method,the material has application value.The composite substrate prepared by this thesis could significantly enhance SERS signal and obtain an extremely detection limit of 10-20mol/L.In this study,the composite substrate was also used in the detection of real food and organic matter.This thesis research mainly has the following four parts:Firstly,Ag/TiO2 array preparation,improve previous TiO2 preparation methods,the process of nanoarray generated and preparation is discussed in detail,even the influence of various conditions on the synthesis.such as:temperature,pressure,reaction time,concentration,etc.Five different kinds of TiO2 nanoarray materials are be achieved in the research,there are nanoline,nanoleaf,nanoorchid,nanoarray,nanobipyramidal.Through experiments,not only the detailed parameters of material synthesis are obtained,but also the mechanism and process of material synthesis are deeply discussed.In the crystal growth condition,the influence strength of conditions is:the concentration>temperature>reaction time,sometimes several conditions can be converted to each other,in the design of the synthesis scheme,the condition can be adjusted to save reagent or energy consumption.The discussion of the synthesis path can be used as a reference for the synthesis method of the same kind of materials,which also make the preparation method have definite application value.Secondly,the composite substrates with different silver thickness was prepared by discussing the magnetron sputtering conditions.In the process of the research,large number of experiments were performed to adjust the thickness of the silver layer.The influence of the thickness of the silver layer on SERS was discussed for different Ag/TiO2 nanoarray composite materials,and the best adhesion conditions of various materials were obtained.Thirdly,the substrate were characterized,mainly include:XRD,XPS,SEM,DRS,contact Angle and methods of photocurrent,through the materials were characterized,learned the morphology structure of the material and components,not only used to interpret SERS intensity performance,at the same time to further understand the material growth process,proof growth kinetics process.Fourthly,conducted SERS test to find the detection limit.Through a large number of experiments,SERS tests were performed on five Ag/TiO2 composite materials with different silver-plating conditions.The composite substrate materials with the optimal SERS performance were obtained.On this basis,the concentration gradient experiment was continued to obtain the SERS detection limits of five kinds of composite substrate materials.The material is also use to test the biological samples and obtain good results.This study discussed in detail the synthesis path and morphology control conditions of TiO2 nanoarray,improved the traditional preparation method,and prepared five TiO2 nanoarrays with different morphology and components,among which the new material "nanoorchid" was prepared for the first time.The optimal thickness of silver layer was determined,and the detection performance of ultra-sensitive silver layer was obtained.The detection limit reached 10-20mol/L.In the detection of biological organic pollutants,the Ag/TiO2 composite substrate showed good performance and strong signal. |
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