Synthesis of the ZnFe2O4/ZnSnO3 nanocomposite and enhanced gas sensing performance to acetone

Acetone is an important biomarker for the diagnosis of diabetes. In this work, the ZnFe2O4/ZnSnO3 nanocomposite was first prepared via a facile two-step hydrothermal method, and then obtained by the subsequent calcination process. The structure, morphology, and composition of the nanocomposite were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunner Emmet Teller (BET), scanning electron microscope (SEM), Transmission Electron Microscopy (TEM) and Fourier transform infrared spectrophotometer (DR-FTIR) techniques, and the gas-sensing performance of the composites were investigated comprehensively. The ZnFe2O4/ZnSnO3 nanocomposite is consisted by the ZnSnO3 cubic and the urchin-like ZnFe2O4. The as-prepared ZnFe2O4/ZnSnO3-0.25 gas sensor shows excellent gas-sensing performance toward acetone, including fast response-recovery time (9 s/16 s to 30 ppm acetone), long-term stability and good humidity resistance at 200°C. The improved gas sensing performance of ZnFe2O4/ZnSnO3-0.25 nanocomposite could be due to its large specific surface area, oxygen vacancy and n-n heterojunction.