Improved room temperature gas sensing performance of SiC/rGO nanosheets based on QCM

SiC/rGO nanosheets (NSs) were prepared by high-temperature gas–solid reaction process based on rGO aerogel template, and used to construct the QCM gas sensor for selective detection of NH₃ at room-temperature. The nanosheets were characterized by XRD, SEM, Raman and BET, and the effects of preparation and annealing temperatures on the structure and gas sensing performance were discussed. SiC/rGO NSs inherited the lamellar structure of rGO successfully, providing more active sites for gas sensing testing, while reducing GO to rGO at the same time. The QCM gas sensor based on SiC-1500–900 (prepared at 1500 °C and annealed at 900 °C) exhibited maximum response of 75.98 Hz to 50 ppm NH₃ at room temperature, with response and recovery times of 16.2 and 19.4 s, respectively. Furthermore, the surface modification process and potential mechanism of gas response enhancement of the annealed SiC/rGO NSs were discussed in detail, which was attributed to the synergistic effects of specific mesoporous nanosheet structure and hydroxyl groups introduced by annealing.