Low concentration isopropanol gas sensing properties of Ag nanoparticles decorated In2O3 hollow spheres

Abstract In order to detect low concentrations of volatile organic compounds (VOCs) for the early diagnosis of lung cancer, sensors based on hollow spheres of In 2 O 3 were prepared through the soft template method. Ag nanoparticle decorated In 2 O 3 composites were synthesized via dipping and annealing. The microstructure, phase composition, element distribution, and state of Ag were analyzed by the scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The gas sensing tests showed that Ag-In 2 O 3 sensors had the highest response to isopropanol at 300 °C. The best response of Ag-In 2 O 3 composite sensor was 5.2, which had a significant improvement compared with only In 2 O 3 . Moreover, the response and recovery time of Ag-In 2 O 3 composite sensor was significantly shortened. The improved sensing properties of Ag-In 2 O 3 composite sensor could be attributed to the Schottky barrier created at Ag-In 2 O 3 interface and catalytical effect of Ag.