Co9S8@In2S3 hetero-nanostructures as highly sensitive and selective triethylamine sensor

Using Cobalt 2-methylimidazole (ZIF-67) as the precursor, Co9S8/In2S3 was successfully synthesized. The characteristic structure of Co9S8/In2S3 is Co Metal-Organic framework (Co-MOF). Co9S8/In2S3 semiconductor material was prepared by the hydrothermal method, which presented a special multi-wrinkled flower-like morphology. The Co9S8/In2S3 semiconductor material has selectivity and high sensitivity to triethylamine (Rair/Rgas=100.3, 20 ppm), ultra-low detection limit (100 ppb), and good linearity relation at working temperature of 300 °C. The products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The growth mechanism of these products was proposed. A possible mechanism to explain the high sensing properties of these morphologies was that the Co9S8/In2S3 material had p-n heterojunction structure characteristics, coupled with its high porosity and specific surface area on the morphology helped to improve the sensitivity to triethylamine (TEA).