Hierarchical assembly of SnO2 nanorod on spindle-like α-Fe2O3 for enhanced acetone gas-sensing performance

Preparing a heterojunction structure in different metal oxides is an efficacious method to improve the gas-sensing properties. In this article, a novelty SnO2 nanorod/spindle-like Fe2O3 heterostructure was successfully fabricated through a simple two-step hydrothermal route. The morphological characterization revealed that the spindleshaped Fe2O3 with length and diameter of 400 and 100 nm were firstly fabricated by a hydrothermal process, and then a large number of SnO2 nanorods (lengths of 30 nm and diameterd of 8 nm) covered the spindle-shaped Fe2O3 uniformly. In order to facilitate better practical applications, the gas sensing performance of sensors based on SnO2/Fe2O3 nanostructures and pure Fe2O3 nanospindles on volatile organic compounds were systematically studied. Gas sensing tests indicated that such hierarchical SnO2/Fe2O3 heterostructures revealed improved acetone sensing performance compared to pure spindle-like Fe2O3, and the enhanced gas-sensitivity performance possibly be attributed to the synergistic effect and heterojunction of the interface between spindle-like Fe2O3 and SnO2 nanorod. Additionally, this research on as-obtained SnO2/Fe2O3 hierarchical assembly may provide a new insight and a rational strategy to upgrade the sensing performance of certain semiconductor metal oxide materials by rationally designing various novel layered nanostructures in the future.