Performance and Mechanism Analysis of Hexagonal Co(OH)F/Carbon Quantum Dots Composite Sensor Synthesized by PVP-Assisted Method for Acetone Gas Detection

Acetone gas sensitivity detection holds significant application value in environmental monitoring, industrial safety, and health assessment. This study presents the first report on the assembly of carbon quantum dots (CQDs) on the surface of hollow hexagonal Co(OH)F for efficient acetone gas detection. The fabricated sensor exhibits the ability to detect acetone at a low concentration of 200 ppb at 120 °C, demonstrating excellent moisture resistance and long-term stability. The incorporation of CQDs not only reduces the operating temperature but also enhances the gas-sensing performance of Co(OH)F, offering a simple and eco-friendly strategy for optimizing gas sensors. We systematically analyzed the synergistic effect between CQDs and Co(OH)F and their role in acetone detection. The surface functional groups of CQDs combine with the Co(OH)F surface, improving electron transfer efficiency and potentially lowering the activation energy of acetone molecule reactions through catalytic effects, enabling efficient low-temperature detection. The modification of Co(OH)F surface chemistry by CQDs strengthens the gas recognition capability. The coupling of CQDs with metal hydroxyl fluoride plays a crucial role through multiple mechanisms, providing an innovative approach for the development of high-performance gas sensors.