Performance Analysis of Graphene Oxide-Coated QCM Sensors for Humidity Detection

This study focuses on developing humidity sensors using a quartz crystal microbalance (QCM) coated with graphene oxide (GO) as the sensing layer. The GO was applied to the QCM’s surface electrodes via drop-casting. The performance of the GO-coated QCM was evaluated at varying relative humidity (RH) levels from $\mathbf{4 0 \%}$ to $\mathbf{9 0 \%}$ RH, examining key parameters such as sensitivity, hysteresis, response time, and recovery time. The results demonstrated that the GO-coated QCM achieved a sensitivity of $91.06 \mathrm{~Hz} / \% \mathrm{RH}$, with response and recovery times of 77 seconds and 16 seconds, respectively. Characterization of surface morphology, surface area, and functional groups that contain oxygen to the GO material was conducted using XRD, SEM, BET, and FT-IR. Moreover, the study emphasizes the significance of optimal mass depositing for enhancing the sensitivity of QCM sensors.