Improvement in Humidity Sensing of Graphene Oxide by Amide Functionalization

• Main Authors: Sumita RANI, Dinesh KUMAR, Mukesh KUMAR
• Format: Article
• Language: English
• Published: IFSA Publishing, S.L. 2015-10-01
• Series: Sensors & Transducers
• Subjects: Amide functionalized graphene oxide; Graphene oxide; Relative humidity sensing; I-V characteristics.
• Online Access: http://www.sensorsportal.com/HTML/DIGEST/october_2015/Vol_193/P_2742.pdf

In this work, the effect of water adsorption on the electrical properties of graphene oxide (GO) and Amide functionalized graphene oxide (AGO) was studied using direct current measurements. AGO was synthesized by chemical method at room temperature. Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy measurements were carried out to verify the functionalization of GO. The films of GO and AGO between aluminum electrodes on SiO2/p-Si (100) substrate were formed by drop casting method. The variation in the I-V characteristics was recorded at different humidity level. It has been observed that the interaction between water molecules with AGO was more as compared to GO. It was reported that electrical properties of GO and AGO are humidity and applied voltage dependent. At low humidity level the response of GO sensor was poor, however at high humidity the conductivity of GO increases. Compared to GO, AGO shows good response. The resistance of the AGO film was approximately 9.87 kW at 10 % relative humidity (RH), and decreases to 1.5 kW at 90 % RH.