The Gas Sensor Based On Metal-organic Frameworks Modified Quartz Crystal Microbalance

In the present thesis, the performances of the three kinds of organic metal frameworkmodified gas sensor have been studied. And a better modification material, organic metalframework, has been discovered. The gas sensors modified by organic metal frameworksshow excellent function for detecting many gas. Prepared three modified electrodes areapplied to the determination of water, pyridine and methanol with satisfactory results.Using drop coating technique, three gas sensors which are modified by organic metalframeworks-Co2(oda)2(4,4’-bipy), Al(OH)(1,4-NDC), Co2(4,4’-bipy)(1,3-BDC), arefabricated. Selecting water, pyridine, methanol as probe, the sensor performances of thesemodified electrodes based on organic metal framework modified are investigated. The resultsshow that the gas sensors based on organic metal framework-Co2(oda)2(4,4’-bipy),Al(OH)(1,4-NDC), Co2(4,4’-bipy)(1,3-BDC), have preferable performances to water,pyridine, methanol respectively. Comparing with references, it has lower detection limit andhigher sensitivity. Firstly, sensor modified by Co2(oda)2(4,4’-bipy) shows good function forwater, and a sensitivity of87.41Hz/ppm, the detection limit is0.16ppm (signal to noise ratioof3:1). In addition, the humidity dependence of the sensor is also investigated in relativehumidity (RH%) range from11%to95%, indicating that this sensor shows good performance.This sensor can be applied in humidity and trace water detection. Then, the pyridine sensorsbased on organic metal framework-Al(OH)(1,4-NDC) had been studied. The results show thatthis pyridine sensor had higher sensitivity; better stability compared with other literaturereports, and shows good selectivity, the frequency shift of sensor shows good linearrelationship with concentration of pyridine. At last, organic metal frameworkCo2(4,4’-bipy)(1,3-BDC) modified methanol sensor has been fabricated by the method ofliterature reported. The preparation conditions such as dispersant and coating load areexperimentally evaluated. And the sensor shows a good linear between Δf andC(concentration of methanol) under the best condition.In this paper, organic metal frameworks with the adsorption characteristics provide anew platform in gas sensors for the preparation of the quartz crystal microbalance.