A highly sensitive VOC gas sensor using p-type mesoporous Co3O4 nanosheets prepared by a facile chemical coprecipitation method

Mesoporous Co3O4 nanosheets were synthesized via a facile chemical coprecipitation method without using of surfactant or template. Mesoporous Co3O4 material was characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) to examine the morphology and microstructure to find out the cause for the highly sensitive sensing behavior. SEM and TEM analyses reveal that the Co3O4 nanosheets consisting of nanoparticles prepared here are porous in nature, with average pore sizes of approximately 50 nm or smaller. The sensor based on porous Co3O4 nanaosheets was used for detecting the volatile organic compounds (VOCs) including ethanol, methanol, acetone, isopropanol, formaldehyde and n-butanol. The results demonstrate that the sensor shows potential for detecting VOCs. The significant improvement of sensitivity is attributed to the porous structure, good contact and relatively small crystal size. The gas sensor shows high response values, fast response and recovery times towards VOCs. So, porous Co3O4 nanosheets are considered as promising sensor material for detecting VOCs. (C) 2016 Elsevier B.V. All rights reserved.