Novel carbon quantum dots enhanced carbon nanotubes-graphene hybrid nanocomposite for VOCs detection

In recent years, researchers have shown a significant interest in exploring carbon-based nanomaterials for their potential applications in sensing technologies. This study introduces the development of an innovative composite material through the integration of quantum dots with carbon nanotubes and graphene. This nanohybrid composite serves as a sensing material for detecting ethanol at room temperature. The carbon quantum dots (CQD) used in this study were synthesized through a solvothermal process and integrated with carbon nanotubes (CNT) and graphene nanoplates (GNP) to investigate the synergistic effects on the composite's structure and its sensing properties. The resulting hybrid composite was applied as a sensitive film onto the surface of a quartz crystal microbalance (QCM) sensor. The hybrid nanocomposite-based sensor demonstrated significantly enhanced sensing sensitivity. At an ethanol concentration of 500 ppm, the CQD-enhanced CNT-GNP composite exhibited approximately 10- and 15-fold higher responses compared to CNT- and GNP-coated sensors, respectively. The response/recovery times of the CQD-enhanced CNT-GNP composite sensor were approximately 2/0.5 min, respectively. The sensor maintained reasonable repeatability and good recovery. The findings highlight the remarkable synergistic effects observed in the sensing performance of carbon-based nanohybrids, demonstrating the promising potential of this approach to enhance the sensitivity of such sensors.