Hierarchical assembly of Fe2O3 nanorods on SnO2 nanospheres with enhanced ethanol sensing properties

Highlights: • Hierarchical Fe₂O₃ nanorods/SnO₂ nanospheres composites with superior ethanol sensing properties were synthesized via hydrothermal method. • Characterization results showed that Fe₂O₃ nanorods were standing upright on SnO₂ nanospheres with the diameter and length are 10 nm and 200–300 nm, respectively, specific surface area of 93.5 m²/g. • The gas sensor based on Fe₂O₃ nanorods/SnO₂ nanospheres nanocomposites possesses good response, short response-recovery time, and good selectivity to ethanol. Combined with other metal oxide is an effective method to improve the sensing properties of SnO₂. In the paper, the heterostructural nanocomposites of Fe₂O₃ and SnO₂ were prepared successfully by a simple and low-cost hydrothermal method, and the nanostructure and morphology were analyzed through a battery of characterization such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), the Brunauer-Emmett-Teller (BET) approach and X-ray photoelectron spectroscopy (XPS). Characterization results exhibit that the diameter of SnO₂/Fe₂O₃ heterostructural nanocomposites and the diameter and length of Fe₂O₃ nanorods are 10 nm and 200–300 nm, respectively. The BET surface area is calculated to be 93.5 m²/g, and the main pore diameter is about 13 nm. According to the gas sensing text, it is obvious that the optimum temperature of SnO₂/Fe₂O₃ heterostructural nanocomposites is 320 °C. When injecting the concentration of 100 ppm ethanol, the response value of SnO₂/Fe₂O₃ heterostructural nanocomposites is 23.512, which is higher than the pure SnO₂ nanospheres. Therefore, the SnO₂/Fe₂O₃ heterostructural nanocomposite will become a promising functional material in monitoring and detecting ethanol.