Mechanism Of Photocatalytic Degradation Of Rhodamine B By Tio2 Nanowire Array With Internal Extraction Electrospray Ionization Mass Spectrometry

By means of hydrothermal synthesis, the TiO2, nanowire array was prepared on the SnO2 conductive glass (FTO) substrate doped with F, and it was combined with the internal extraction electrospray ionization mass spectmmetry (iEESI-MS) to realize the detection of Rhodamine B intermediate product and the conjecture of its reaction mechanism. The effects of ion source voltage, ion transmission tube temperature and eluting agent on the signal strength of rhodamine B and its degradation products were systematically investigated. The results showed that the optimum Rhodamine B intermediate product and its degradation product signal could be obtained under the condition that the photocatalytic reaction time was 2 h, the reaction solution volume was 15 mu L the ion source voltage was 3 kV, the ion transmission tube temperature was 300 t, and the eluting agent was 0.5% methanol-acetic acid (volume ratio). Under the optimized conditions, 8 kinds of intermediate products were detected from Rhodamine B reaction solution, and the degradation mechanism of rhodamine B was inferred. In this method, the detection limit (S/N >= 3) of rhodamine B quantitative analysis is 0.1 mu g/L, and the relative standard deviation (RSD, n=6) is 2.1%-7.3%, which shows that this method has the characteristics of low testing limit, high sensitivity, less sample consumption during detection, fast analysis speed and simple operation. In addition, this method can also be used to detect the intermediate products of other photocatalytic reactions, widen the application of mass spectrometry in the field of environment, and provide new ideas for the future exploration of the degradation mechanism of environmental pollutants.