Sensing properties of ZnS@ZnO core-shell based triethylamine sensor fabricated using solvothermal and sintering methods

Abstract

Since poisonous and flammable characteristics of triethylamine (TEA), developing TEA sensor is increasingly essential to guarantee industrial production and life safety. Herein, a novel [email protected] (SO) core-shell nanostructure was prepared by a two-step method involving solvothermal and sintering procedure. X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy investigation and Brunner−Emmet−Teller measurements revealed that the SO has a fine size of 25 nm in diameter and a thin shell of ZnO, with a large specific surface area of 28.3 m2/g. The gas sensitivity measurement showed that SO heterojunction not only has highly enhanced sensitivity and strong anti-humidity ability, but also significantly shortened the response and recovery time, compared to the ZnS sensor. The optimal sensitivity of the SO sensor is 74.65, and its response/recovery time is 3 s/176 s toward 100 ppm TEA at 200 oC. The enhanced sensing performance can be attributed to rapid electron flow and significant change in the electron depletion layer at the n-n heterojunction interface between ZnS and ZnO. Therefore, the SO sensor possesses a promising application prospect in TEA detection.