Hierarchical In2O3 nanostructures for improved formaldehyde: sensing performance

Formaldehyde (HCHO) gas is a hazardous indoor air pollutant; thus, it is urgent to achieve rapid and accurate detection of HCHO. In this paper, hierarchical In2O3 nanostructures have been prepared via a simple hydrothermal method. The phase purity, morphology, microstructure are characterized by XRD, SEM and TEM. The HCHO sensing performances of the as-synthesized In2O3 samples-based sensor are systematically studied. The sensor displays ultra-fast response speed, excellent selectivity, sensitivity, and stability. The response time to 50 ppm formaldehyde is about 0.9 s and the response value is 22. The enhanced gas sensing characteristics can be ascribed to unique hierarchical nanostructures composed with orderly arranged nanrods. These performances make the hierarchical In2O3 nanostructures a hopeful candidate for formaldehyde sensor in practical applications.