Preparation Of Noble Metal/semiconductor Composite SERS Substrates And Their Application In Detection Of Dye Molecules

Dyeing wastewater contains benzene series,anthraquinone,aniline and other compounds,which are carcinogenic,teratogenic and mutagenic,and seriously pollute the living environment of human beings.The traditional detection methods of organic matter in dyeing wastewater mainly include gas chromatography,liquid chromatography,gas-liquid chromatography,etc.However,these methods are complicated to operate and expensive.The detection technology based on surface-enhanced Raman scattering（SERS）effect has broad application prospects in the field of environmental pollutant detection due to its advantages of high sensitivity,simple operation,and non-destructiveness to samples.The key to realizing SERS detection-based methods is to prepare substrates with high SERS activity and signal uniformity.In this paper,three noble metal/semiconductor composite SERS substrates with high SERS activity and signal uniformity were constructed,and the detection of dye molecules in common dyeing wastewater was realized based on the three prepared substrates.The specific research contents and results of this paper are as follows:（1）A preparation method of gold nanoparticle-modified HKUST-1 nanorod array SERS substrate was invented.First,the Cu（OH）₂ nanorod arrays were obtained on the Cu mesh by chemical etching method,and then the Cu（OH）₂ nanorods were immersed in 1,3,5-trimesic acid solution to obtain the HKUST-1 nanoblock assembly.The nanorod array was then modified by sputtering gold nanoparticles on its surface to prepare a Cu mesh/Cu（OH）₂@HKUST-1@Au composite SERS substrate.By adjusting the growth time of Cu（OH）₂ nanorods,the deposition time of HKUST-1,the concentration of solution,and the time of sputtering Au nanoparticles,a nanocomposite SERS substrate with excellent performance was obtained.Based on this SERS substrate,the low concentration detection of 10^-9 M rhodamine 6G（R6G）molecule was realized,which has certain application prospects in the detection of pollutants such as toxic dye molecules.（2）A method for fabricating a structured array SERS substrate of Ag nanoparticle-modified polyacrylonitrile（PAN）nanopillars@Fe₂O₃ nanorods@Ag nanoparticles was developed.Firstly,a large-area,uniform and ordered PAN nanopillar@Fe₂O₃ nanorod array was constructed by hydrothermal method using PAN nanopillar array film as the substrate,and then Ag nanoparticles were modified on the surface to obtain highly ordered PAN nanopillars.@Fe₂O₃ nanorods@Ag nanoparticle array substrate.The effects of the hydrothermal reaction time and the time of sputtering Ag nanoparticles on the substrate morphology and SERS activity were investigated,and the sensitivity and uniformity of the substrate were characterized.The PAN nanopillars@Fe₂O₃nanorods@Ag nanoparticle arrays exhibit excellent sensitivity to the dye molecule R6G as well as to p-mercaptoaniline（4-ATP）.（3）Develop an Ag nanoparticle-modified copper oxide（Cu O）nanorod structure array substrate（Cu mesh@Cu O nanorod@Ag nanoparticle）,study the control factors of Cu O nanorod,and adjust the sputtering of Ag nanoparticle by adjusting time to obtain the optimal preparation parameters for SERS substrates.The detection of 10^-9 M 4-ATP and 10^-9 M R6G molecules is realized based on Cu mesh@Cu O nanorods@Ag nanoparticle array,which has a good application prospect in the detection of dye molecules.