Construction of multi-walled carbon nanotubes/ZnSnO ₃ 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)/ZnSnO ₃ 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, ZnSnO ₃ and MWCNTs/ZnSnO ₃ heterostructures are systematically investigated, respectively. The results show that MWCNTs/ZnSnO ₃ heterostructures have better sensing properties compared with pure MWCNTs and ZnSnO ₃ sample. Specifically, MWCNTs/ZnSnO ₃ 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.