Sensitive, real-time and anti-interfering detection of nitro-explosive vapors realized by ZnO/rGO core/shell micro-Schottky junction

The ZnO/rGO core/shell micro-Schottky junction was successfully prepared via a one-step facile hydrothermal method. It is found that the resulting gas sensor exhibited excellent capability to detect trace vapor of nitro-explosives, typically, the responses towards 9 ppb 2,4,6-trinitrotoluene (TNT) and 4.9 ppt hexogen (RDX) reach to 56.8% and 80%, respectively, and all the response times are less than 5 s. Most importantly, superior anti-interfering property is shown even towards interfering gases of ppm level. Furthermore, it is demonstrated that with the wrapping of rGO, the response values of the pure ZnO-based sensor for TNT and RDX detection were boosted by 5.5 and 3.4 times. The enhanced sensing performance is attributed to the micro-Schottky junction built at the interface of ZnO and rGO. The present work demonstrates that the ZnO/rGO core/shell micro-Schottky junction is an excellent candidate material for explosives detection. (C) 2016 Elsevier B.V. All rights reserved.