Research On Gas Identification Based On Optical Coupling Sensor Array And Principal Component Analysis

The sensor acts as the primary detection device for signal transmission,processing,storage,and recording.The reported sensors generally have good sensitivity.The detection limit of volatile organic compounds(VOC)has reached several tens of ppb,and has even expanded to more than ten ppb,however,poor selectivity is still an urgent problem to be solved.For this difficulty,in this topic,the selectivity is improved in two ways: 1)By applying ultraviolet light to the sensor array,the three sensing units exhibit six sensing characteristics,combined with the PCA algorithm,artificially simplifying the sensor array and enhancing the selectivity;2)using the core-shell structure sensitive material as the sensitive electrode achieves high selectivity to the composite gas by adjusting the thickness of the shell wall and minimizes the workload of the post-processing signal.For the problem of Inadequate detection limit of electrochemical sensors,this paper adopts the photoelectric coupling sensing technology based on mixed potential response behavior.The research results in this paper can effectively reduce the workload of post-processing signals and reduce the volume of the sensor array.It has certain reference significance for the development of electrochemical sensors.The specific research results are as follows:1)A zirconia-based electrochemical sensor array comprised of Zn O/In2O3 composites SE(vs.a Mn-based RE)is designed.Illumination and the raise of the amount of In2O3 in the composites significantly affected the sensing behaviour of the sensor array.After exposure to the illumination,the sensor array gives satisfactory response magnitude and detection limit,and selectively enhanced response signal to specific gases is further confirmed for the sensor array operated at light on.6 different response modes are produced compared to sensor arrays that operate when the lights are turned off individually.The 6 measured VOCs can then be manually distinguished by a sensor array consisting of only 3 types of Zn O/In2O3 composites SE by processing all response patterns from the source using the PCA algorithm.2)A zirconia-based electrochemical sensor consisting of ?-Fe2O3@Zn O core-shell photosensitive materials is designed.In the synthesis of ?-Fe2O3@Zn O,we controlled the thickness of Zn O on the shell wall by adjusting the amount of zinc.The sensor prepared by different shell wall thicknesses was tested by passing the target gas.It was found that ?-Fe2O3@0.15 MZn O showed light enhancement after addition of nonane and 3-methylhexane,while ?-Fe2O3@0.2 MZn O showed only a light enhancement effect on nonane after adding light,showing a very good single selectivity.Comparing the test data with Zn O/In2O3 composite material SE,?-Fe2O3@Zn O core-shell photosensitive material sensor can effectively reduce the workload in signal processing,and according to the experimental data,it can be effectively achieved by adjusting the nuclear material,shell material or shell wall thickness,which provides a favorable basis for the gas sensor to achieve directional selection.