Highly sensitive and low detection limit of ethanol gas sensor based on CeO2 nanodot-decorated ZnSnO3 hollow microspheres

In order to achieve high response, excellent selectivity and stable detection of ethanol vapor, CeO2 nanodot-decorated ZnSnO3 hollow microspheres with heterostructures that could meet the requirements of ethanol detection were obtained through a convenient hydrothermal method. The prepared uniform nanodot-decorated hollow microspheres were observed by SEM and TEM, it is noticeable that CeO2 nanodots of about 10 nm were uniformly anchored on the surface of ZnSnO3 hollow microspheres with a diameter of 0.8–1.4 μm. Compared with the pure ZnSnO3, the 15% CeO2/ZnSnO3 hollow microspheres exhibited higher response (219.2) to 100 ppm ethanol, superior selectivity (ethanol) and rapid response recovery. In addition, a scientific and effective method was used to calculate the ultra-low theoretical gas detection limit (11.3 ppb) of the CeO2 nanodot-decorated ZnSnO3 hollow microspheres. The outstanding gas sensing properties were attributed to the existence of large amounts of dissociative oxygen and the n-n heterojunction between ZnSnO3 and CeO2. Meanwhile, our work confirmed that CeO2 nanodot-decorated ZnSnO3 hollow microspheres have satisfied the application needs of ethanol detection.