Microwave-assisted synthesis of Co-doped SnO2/rGO for indoor humidity monitoring

摘要

The evaluation of indoor humidity is challenging compared to other environmental parameters such as light intensity, temperature, sound and so forth. The proper selection of sensing materials and structural tuning will lead to high-performance humidity sensors. Herein, the SnO2/rGO and SnO2/rGO doped with Co nanocomposite were produced by microwave route. The obtained nanocomposite was characterized by XRD, SEM, EDAX, DTA, TGA, FTIR, Raman, and HRTEM. The successful incorporation of Co onto the rGO/SnO2 is affirmed by the XRD and supported with matching SEM and TEM outcomes where nanoscale particles exist. FTIR reveals the existence of the C=C stretching band at similar to 1570 cm(-1) indicating graphene network sustaining upon reduction. Micro-pores presence is claimed by the adsorption-desorption isotherm curve. The humidity sensing behavior of both structures was evaluated in a wide range of humidity (11-97 RH). The obtained results confirmed that best working frequency for highest humidity change is 50 Hz. Furthermore, upon doping the SnO2/rGO composite with Co, sensitivity, the response time and recovery time has improved reaching 52 s and 100 s respectively.