Sensitive performance of NO2 gas sensor enhanced by f-Ti3C2Tx/ZIF-8 heterostructures
The f-Ti3C2Tx/ZIF-8 composite material with heterostructures was synthesized by electrostatic self-assembly technology.The phase structure and microstructure of synthesized samples were characterized by FESEM,XRD,N2 isothermal adsorption-desorption tests and their gas sensing properties estimated via a self-designed equipment with four test channels.The material analysis and testing showed that ZIF-8 material with regular shape was well-distributed on the surface and between layers of two-dimensional few-layered Ti3C2Tx,and there existed a typical heterostructure at the interfaces.The gas sensing performance tests indicated that the gas sensing response of the composite material toward 100μL/L NO2 was as high as 98.35％,which was 2.1 times that of the ZIF-8 material.The heterostructures formed by the recombination of strongly conductive two-dimensional f-Ti3C2Tx and ZIF-8 not only provided conductive channels for the free electrons generated by the surface reaction of ZIF-8 and gas,but also strengthened the separation efficiency of electrons and holes during the gas-solid reaction on the surface of the composite material through the interface effect.Therefore,the gas sensing performances of the composite material toward NO2 gas were significantly improved.Meanwhile,the layered structure of few-layered f-Ti3C2Tx/ZIF-8 composite material provided convenient diffusion paths for gas molecules to the surface of ZIF-8.
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