Metal-organic frameworks-derived hollow Co3O4 nanotubes for efficient detection of toluene vapor

Low chemical reactivity of toluene remains a limiting factor for its efficient detection. Catalytic oxides (eg. Co3O4)-based sensors always exhibit reliable selectivity towards toluene vapor owing to the specific cata-lytic oxidation activity. However, the sensor response (especially the actual detection limit) still requires for further improving in a harsh ambience. In this paper, a metal-organic framework (MOF)-derived hollow Co3O4 nanotubes has been demonstrated using a sacrificial template (MoO3 nanorods) method. Benefiting from the efficient surface and internal spaces for gas diffusion and gas-solid interaction, this hollow na-notubular Co3O4-based gas sensor declares a low actual detection limit (similar to 1 ppm), favorable selectivity, and reliable stability towards toluene gas at 200 degrees C. Moreover, the sensor responses slightly reduce as the in-creased ambient humidity under a wide range (25-95 %), indicating a suitable feature of anti-humidity response. This work sheds the rationally designing catalytic oxides for detecting low reactive gas molecules (eg. toluene).(c) 2022 Elsevier B.V. All rights reserved.