Preparation and morphology controlling of Co₃O₄ nanostructures and their gas-sensing properties

Co₃O₄ nanorods and nanosheets were prepared via a facile fluorine-mediated hydrothermal method, followed by thermal conversion. Both the Co₃O₄ nanorods and nanosheets exhibited a spinel structure, assembling by 30 nm nanograin along one and two dimensions. The primary exposed facet of the Co₃O₄ nanorods was identified as (110), while the main exposed plane of the Co₃O₄ nanosheets was (112). Gas sensing results showed the Co₃O₄ nanorods sensor exhibited higher sensitivity. The Co₃O₄ nanorods sensor demonstrated excellent sensitivities to toluene and xylene at 200°C, making it a promising candidate for the detection of these specific volatile organic compounds.

The response of the Co₃O₄ nanorods sensor to the test gases at 200°C.