In-doped SmFeO3 nanoblocks-assembled microsphere composited on graphene gas sensor for ppb-level aniline gas detection

Aniline is not only a type of carcinogen but also the raw material for the preparation of drugs. Therefore, the detection of aniline is of great significance in human health and environmental protection. In this paper, rGO-SmFeO 3 -In nanocomposites were prepared by hydrothermal method for the detection of aniline by combining the excellent properties of rGO and In. The lattice, micro-morphology, elemental distribution and chemical state of the gas-sensitive material were analyzed through XRD, SEM, EDS, and XPS characterizations, which confirmed that the In-doped SmFeO 3 (SFO) nanoblocks-assembled microspheres composited on rGO were successfully prepared, and the nanocomposite possessed abundant oxygen vacancies. The gas sensitivity test results showed that 2 wt% rGO-SFO-1.5 wt% In had excellent gas sensitivity to aniline gas. At 200℃, 2 wt% rGO-SFO-1.5 wt% In had a higher response value of 64.2–100 ppm aniline, which was 6 times that of SFO, and showed a faster response and recovery process (10 s/5 s). In addition, the sensor demonstrated its ability to detect aniline at a lower detection limit of 1 ppb with a response rate of 1.25. Furthermore, the gas sensor was integrated into the embedded system to achieve real-time detection of aniline gas. This study provides a new reference for the development of low detection limit and high sensitivity aniline gas sensor.