Template-free Synthesis of Cubic-rhombohedral-In2O3 Flower for ppb Level Acetone Detection

Publication date: Available online 4 April 2019Source: Sensors and Actuators B: ChemicalAuthor(s): Fang Chen, Man Yang, Xi Wang, Yang Song, Lanlan Guo, Ning Xie, Xueying Kou, Xiumei Xu, Yanfeng Sun, Geyu LuAbstractAnalyzing volatile organic compounds in exhaled breath is a noninvasive method that has potential for disease assessment. Herein, acetone sensors based on porous In2O3 flowers are synthesized through a facile solvothermal method. Structural characterizations demonstrate that the three-dimensional In2O3 flower-like structure comprises porous ultrathin two-dimensional nanosheets. The structural porosity results in a large specific surface area and fast gas diffusion, which can improve the gas sensing performance. The crystalline structure of the prepared hierarchical flower-like In2O3 is a mixed phase of rhombohedral and cubic phases according to the XRD patterns. The sensing properties of the cubic-rhombohedral In2O3 (bcc-rh-In2O3) are also investigated. Compared with commercial-In2O3-based sensor, the bcc-rh-In2O3 sensor exhibits 2.9 times higher response (Ra/Rg = 12) and shorter response time (ca. 2 s) toward 50 ppm acetone. The bcc-rh-In2O3 sensor has a low detection limit of 10 ppb in atmosphere and can easily distinguish acetone from ethanol. The extraordinary properties of the bcc-rh-In2O3 sensor are mainly attributed to the n-n heterojunction between rh-In2O3 and bcc-In2O3.
Source: Sensors and Actuators B: Chemical - Category: Chemistry Source Type: research