Zigzagging graphitic ribbons: Synthesis, characterization, and acetone vapor sensing

The fast sensing highly volatile and flammable liquids of organic compounds is an urgent scientific goal for developing devices aimed at health and safety monitoring. The high superficial area, high porosity, and electrochemical properties of carbon nanotube/fiber sponges make them promising materials for sensing organic compounds. In this study, we synthesized zigzagging graphitic ribbons (ZGR) sponges employing the aerosol-assisted chemical vapor deposition (AACVD) method at temperatures of 980 °C, 1020 °C, and 1050 °C. We characterized the morphology, composition, thermal stability, and surface chemistry of the ZGRs using various techniques. The ZGRs exhibited a defective, corrugated, and oxygen-functionalized surface. XPS characterizations revealed the presence of ether, carbonyl, carboxyl, aldehyde, and hydroxyl groups on the ZGR surface. TEM characterizations showed graphitic materials with unusual black zones attributed to sp3 carbon hybridization or strained graphite. Sensors based on ZGR sponges were used at room temperature for detecting acetone gas vapor. The electrical resistance response was monitored by varying the concentration of acetone gas vapor. The results revealed that the sensors remained stable over multiple cycles and exhibited fast response times (2–12 s). Interestingly, acetone serves as a selective breath marker for diabetes, suggesting that our sensors could be used for non-invasive diabetes monitoring. Finally, we performed van der Waals density functional theory calculations to elucidate the TEM black zones and the interaction of the acetone molecule with oxygen functional groups hosted in graphitic materials.