Construction of multi-walled carbon nanotubes/ZnSnO3 heterostructures for enhanced acetone sensing performance

Carbon nanotubes (CNTs) have attracted many researcher's attention in gas sensing field because of their excellent physical and chemical properties. Herein, multi-walled carbon nanotubes (MWCNTs)/ZnSnO3 heterostructures have been obtained by a simple hydrothermal method without additional annealing process. The structural and composition information are characterized by x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS). The acetone sensing properties of pure MWCNTs, ZnSnO3 and MWCNTs/ZnSnO3 heterostructures are systematically investigated, respectively. The results show that MWCNTs/ZnSnO3 heterostructures have better sensing properties compared with pure MWCNTs and ZnSnO3 sample. Specifically, MWCNTs/ZnSnO3 heterostructures exhibit not only high responses of 24.1 and rapid response/recovery speed of 1 s/9 s to 100 ppm acetone, but also relatively good repeatability and long-term stability. The enhanced sensing performance is analyzed in detail. In addition, this work provides the experimental and theory basis for synthesis of high-performance MWCNT-based chemical sensors.