Assembling MOF on CNTs into 0D-1D heterostructures for enhanced volatile organic compounds detection

The rapid advancement of the Internet of Things has created a substantial demand for portable gas sensors. Nevertheless, the development of gas sensors that can fulfill the demanding criteria of high sensitivity and rapid response time continues to pose a considerable challenge. Herein, an in-situ anchoring strategy is proposed to construct CNTs@MOF heterostructure to establish strong electronic coupling and charge relocation for enhancing the monitoring capabilities of isopropanol (freshness markers for fruits) at room temperature. The in-situ anchoring process prevents Zn-MOF (ZIF-8) self-aggregation, ensuring efficient transport channels for target analytes and enhancing active site utilization. Moreover, the synergistic effect of each component in the composite is optimized. Consequently, the gas sensor based on the CNTs@ZIF-8 heterostructure achieved an ultrahigh isopropanol response of 57.87 (40 ppm, R_a/R_g) at room temperature and 60% relative humidity, exhibiting rapid response kinetics (38 s, 30 ppm) and durability. This study offers a fresh perspective on the structural design of oxygen-inert CNTs materials.