Surface-Enhanced Infrared Adsorption Spectroscopy On Mixed Halogens Hybrid Perovskites: Fundamental And Applications

Surface-enhanced infrared absorption spectrum?SEIRA? can improve the detection sensitivity of substance to be detected, the subject of the use of nitro compounds SEIRA effects were analyzed and compared with the perovskite family different halogen metal halide formed on the same molecular enhancement, select CH₃NH₃ Pb Ix Cl3-x enhancement factor based on peak shape, peak factors such as SEIRA b 3Pb Br3 ase material for picric acid, infrared absorption spectroscopy to assess the effect of dinitrotoluene.First, the use of concentrated acid?HCl, HBr, HI? and methylamine ethanol solution was prepared by the corresponding organic amine salts CH₃NH₃X?X = Cl, Br, I?, then the organic amine salts and metal halide Pb X2?X = Cl, Br, I? precursor solution was spin-coated on a Ca F2 substrate to be annealed to obtain an organic- inorganic hybrid perovskite thin film substrate material. And hybrid perovskite material IR, UV-Vis, fluorescence spectroscopy, SEM characterization.Experimental results show that the optimal annealing conditions CH₃NH₃ Pb Clx Br3_-x: 95 ?, 60 min, while CH₃NH₃ Pb Ix Br3_-x CH₃NH₃ Pb Ix CI_3-x, the optimal annealing conditions are: 100 ?, 45 min. Annealed by a film obtained substantially smooth, and better quality. 3: 1 was the hybrid perovskites infrared absorption peak intensity better than the 1: 1 ratio obtained perovskite. Silica gel composite main absorption peak did not receive too much interference, but the intensity of the peak of a slight decline. Silica film can be drawn to identify the target molecule still has a good infrared enhancement effect, and greatly improve the stability of the hybrid perovskite with mixed halogen hybrid perovskite compound formed, for infrared enhancement effect. is the first time the hybrid perovskite thin films for surface-enhanced infrared absorption for the chemical analysis of quantitative and qualitative analysis, and the results show that this method can infrared absorption enhancement and quantitative analysis can be performed, in a certain range with good linearity. Meanwhile, potential interfering substances have also been explored, indicating the use of toluene as the extraction solvent detect its infrared spectrum of the sample, the ammonium nitrate, sodium carboxymethylcellulose and sodium silicate infrared detecting DNT has no effect, you can use this method of detecting explosives in DNT. Peak height of the sample concentration regression analysis, the results of nitro compounds in water 0.0005 0.005 mol / L showed good linear regression equation further proof that the method of surface-enhanced infrared absorption feasible. The most important measure surface enhanced infrared absorption effect of the parameters of surface enhancement factor(Enhanced for picric acid, CH₃NH₃ Pb Br3, the enhancement factor CH₃NH₃ Pb I3 composite films 15, 18 are maximum; for CH₃NH₃ Pb Ix CI_3-x CH₃NH₃ Pb Ix Br3_-x, CH₃NH₃ Pb Clx Br3_-x compound the highest attainable 18.6?22.4?30.7.