Facile strategy to synthesize porous GO/ZnO heterostructure for enhanced acetone gas sensing properties

Abstract

Rapid, accurate and reliable detection of harmful gases is crucial criterion for the industrial production, environmental monitoring, medical diagnosis and other fields. To address the issue, in this paper, porous structure of GO/ZnO acetone gas sensing materials was introduced by solid phase reaction at room temperature after calcined at 600 °C. ZnO nanorods with lengths of 2–5 µm were anchored on the surface of porous GO, displaying a unique “coral-like” 3D nanostructure. The sensor based on GO/ZnO heterostructure exhibits a high response (42.9) towards 50 ppm acetone at 200 °C, fast response/recovery time (3.2/7.2 s), good selectivity and stability. The substantially enhanced gas sensing properties are primarily attributable to the unique porous structure of GO, plentiful oxygen vacancies and efficient electron mobility at the GO/ZnO heterojunction, which not only increases the specific surface area to provide more active sites for the gas adsorption, but also supplies more channels to facilitate the diffusion of gas molecules and favours the enhancement of gas detection properties. Moreover, this study can contribute to the realization of a porous structure of GO/ZnO that can be applied for the design of high performance sensing materials.