The Effect of rGO-Doping on the Performance of SnO2/rGO Flexible Humidity Sensor

• Published in: Nanomaterials (Basel, Switzerland) Vol. 11; no. 12; p. 3368
• Main Authors: Yan, Huangping, Chen, Zilu, Zeng, Linyuan, Wang, Zijun, Zheng, Gaofeng, Zhou, Rui
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 12.12.2021; MDPI
• Subjects: Bend radius; breath monitoring; Chemical composition; Doping; Electrodes; Electron microscopy; Fabrication; Flexibility; Graphene; Humidity; humidity sensor; Microscopy; Nanocomposites; Raman spectroscopy; Respiration; Response time; Scanning electron microscopy; Sensitivity; Sensors; SnO2/rGO nanocomposite; Tin dioxide; Transmission electron microscopy; X-ray diffraction; China; Japan
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano11123368

The development of a flexible and high-performance humidity sensor is essential to expand its new applications, such as personal health monitoring and early diagnosis. In this work, SnO2/rGO nanocomposites were prepared by one-step hydrothermal method. The effect of rGO-doping on humidity sensing performance was investigated. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectroscopy were used to characterize the nanostructure, morphology and chemical composition of SnO2/rGO nanocomposites. The SnO2/rGO humidity sensitive film was prepared by electrospinning on a polyimide film modified with gold electrodes. The humidity test results show that different doping ratios of rGO have different effects on humidity sensing properties. Among them, the sensor with 2 wt% rGO-doping has a high sensitivity (37,491.2%) within the humidity range as well as the fast response time (80 s) and recover time (4 s). Furthermore, the sensor with 2 wt% rGO-doping remains good flexibility and stability in the case of bending (1000 times). The sensitivity of the 2 wt% rGO-doping sensor at the bending radius (8 mm and 4 mm) is 48,219% and 91,898%, respectively. More importantly, the sensor could reflect different breathing states clearly and track breathing intervals as short as 3 s. The SnO2/rGO flexible humidity sensor with accuracy, flexibility and instantaneity as well as the facile fabrication strategy is conceivable to be applied in the potential application for human health real-time monitoring.