3-Aminopropyltriethoxysilane functionalized ZnO materials for improving the gas sensitivity to 2-butanone

In recent years, researchers have discovered that self-assembled monolayer functionalized surfaces could improve the gas-sensing performance of semiconductor oxide-based sensors. In the present work, metal-organic framework material ZIF-8 was selected as the self-sacrificial template, and then ZIF-8 materials were calcined at a high temperature to obtain ZnO nanoparticles . Subsequently, the surface of ZnO was modified to install a single layer of 3-aminopropyltriethoxysilane (APTES). In comparison with the pure ZnO-based sensor, the sensor based on 0.5 vol% APTES/ZnO had higher response to 2-butanone. The response has remarkably improved mainly due to APTES molecules capture electrons from the surface of ZnO to widen the electron depletion layer . In addition, the amine (–NH 2 ) group of the APTES monolayer enhanced the specific interaction between the sensing material and 2-butanone, thereby the performance of the sensor was improved. After functionalization with 0.5 vol% APTES, the lower detection limit of the sensor reached as low as 200 ppb, while that of the pure ZnO-based sensor was 500 ppb.