基于杂化钙钛矿表面增强红外光谱研究

发布时间：2018-09-14 11:32

【摘要】：表面增强红外吸收(SEIRA)效应,指有机化合物分子吸附在纳米金属基底表面的红外信号比一般测量下得到的强度增加了几个数量级。几乎所有的过渡金属及稀有金属表面都具有表面增强红外吸收效应,目前应用最广泛的是Au、Ag纳米薄膜的SEIRA效应,但是这些金属价格昂贵。研究表明,几乎所有的过渡金属基底对有机分子都具有SEIRA效应。表面增强红外吸收基底的选择和制备对增强性能尤为重要,如何简单,快速的制备出表面增强红外基底一直是研究的热点。有机-无机杂化钙钛矿作为一种半导体材料,具有特殊的光学性能,目前没有关于用杂化钙钛矿结构晶体薄膜材料作为表面增强红外吸收基底的相关报道。本文利用有机-无机杂化钙钛矿结构薄膜材料作为表面增强红外基底。采用紫外-可见吸收光谱仪,差热-热重分析仪,XRD,SEM和傅里叶红外变换光谱仪等手段对基底材料进行表征,并对探针分子丙烯酰胺,L-半胱氨酸等红外吸收效应进行了评估,最后将基底材料用于化学分析检测中,研究内容具体如下:首先,利用溶剂蒸发法制备有机-无机杂化钙钛矿结构晶体材料,并用旋涂法制备了杂化钙钛矿薄膜。此外,对所制备的杂化钙钛矿结构晶体材料和薄膜材料进行了一系列表征,实验结果表明,所制备的杂化物具有捕获光电子的能力和热稳定性。通过扫描电镜(SEM)表征薄膜材料表面形貌,发现所制备的杂化钙钛矿薄膜表面基本均匀平整,质量较好。其次,以杂化钙钛矿薄膜CH3NH3Pb X(X=Cl、Br、I)作表面增强红外基底,探究了丙烯酰胺的SEIRA效应,表明,这些薄膜基底材料对丙烯酰胺分子的红外信号具有增强效应,且比较了CH3NH3Pb Cl3,CH3NH3Pb Br3,CH3NH3Pb I3三种薄膜基底对丙烯酰胺红外信号的增强效应,估算其增强因子分别为80,150,82。CH3NH3Pb Br3的增强效果最好,因此,选择杂化钙钛矿CH3NH3Pb Br3薄膜作为红外基底对L-半胱氨酸,胞嘧啶核苷(cytidine)的表面增强红外效应(SEIRA)进行评价,结果表明该活性基底对这两种探针分子的红外吸收信号都有增强效果。最后,采用表面增强红外吸收光谱(SEIRAS)技术对面粉中的过氧化苯甲酰(BPO)进行痕量检测,实验中选择BPO的特征吸收峰1959cm-1和1224cm-1进行分析。结果表明,在1959cm-1处,纯的BPO在浓度在0.004mol/L~0.064 mol/L范围内,其线性回归曲线为y=2.8655x+0.0133,相关系数为0.9958,面粉提取液中BPO在浓度为0.004mol/L~0.064 mol/L范围内,其线性回归曲线为y=8.2405x-0.0019,相关系数为0.9970,回收率为100.4%,RSD为1.01%。在1224cm-1处,纯的BPO在浓度在0.004mol/L~0.064 mol/L范围内,其线性回归曲线为y=2.004x+0.0155,相关系数为0.9970,面粉提取液中BPO在浓度为0.004mol/L~0.064 mol/L范围内,其线性回归曲线为y=7.4398x-0.0013,相关系数为0.9949,回收率为101%,RSD为1.42%。
[Abstract]:Surface-Enhanced Infrared Absorption (SEIRA) effect refers to the intensity of infrared signals adsorbed on the surface of nano-metal substrates by organic compounds by several orders of magnitude. Almost all transition metals and rare metals have surface-enhanced infrared absorption effect. At present, Au and Ag nano-thin are widely used. Studies have shown that almost all transition metal substrates have SEIRA effects on organic molecules. Selection and preparation of surface-enhanced infrared absorption substrates are particularly important for enhancing properties. How to fabricate surface-enhanced infrared substrates simply and quickly has been a hot research topic. As a kind of semiconductor material, mechanical hybrid perovskite has special optical properties. At present, there is no report about using hybrid perovskite crystal film material as surface enhanced infrared absorption substrate. The substrate materials were characterized by spectroscopy, DTA, XRD, SEM and Fourier transform infrared spectroscopy. The infrared absorption effects of the probe molecules, such as acrylamide, L-cysteine, were evaluated. Finally, the substrate materials were used in chemical analysis and detection. The research contents are as follows: Firstly, solvent evaporation method was used. The organic-inorganic hybrid perovskite crystal materials were prepared and the hybrid perovskite films were prepared by spin-coating method. In addition, the hybrid perovskite crystal materials and film materials were characterized. The experimental results show that the hybrid materials have the ability to capture photoelectrons and thermal stability. The surface morphology of the hybrid perovskite films was characterized by SEM, and it was found that the surface of the hybrid perovskite films was uniform and smooth with good quality. Secondly, the hybrid perovskite films CH3NH3Pb X (X=Cl, Br, I) were used as surface enhanced infrared substrates. The SEIRA effect of acrylamide was investigated. The results show that the hybrid perovskite films have infrared signal for acrylamide molecules. The enhancement effect of CH_3NH_3Pb Cl_3, CH_3NH_3Pb Br_3, CH_3NH_3Pb I3 on infrared signal of acrylamide was compared. The enhancement factors of CH_3NH_3Pb Br_3 were estimated to be 80,150,82. The surface-enhanced infrared effect (SEIRA) of ytidine was evaluated. The results showed that the active substrate could enhance the infrared absorption signals of the two probes. Finally, surface-enhanced infrared absorption spectroscopy (SEIRAS) was used to detect BPO in flour. The characteristic absorption peak of BPO was 195. 9 cm-1 and 1224 cm-1 were analyzed. The results showed that at 1959 cm-1, the linear regression curve of pure BPO was y = 2.8655x + 0.0133 in the concentration range of 0.004 mol/L ~ 0.064 mol/L, the correlation coefficient was 0.9958, and BPO in flour extract was y = 8.2405 x-0.0019 in the concentration range of 0.004 mol/L ~ 0.064 mol/L, and the correlation coefficient was 0.997. The linear regression curve of pure BPO was y=2.004x+0.0155 at the concentration of 0.004mol/L~0.064 mol/L, the correlation coefficient was 0.9970, and the linear regression curve of BPO in flour extract was y=7.4398x-0.0049 at the concentration of 0.004mol/L~0.064 mol/L, and the correlation coefficient was 0.9949. The rate is 101%, RSD is 1.42%.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.2;O657.3

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