Enhancing Gas Sensing Properties Of Co₃O₄ By Morphology Controlling And Material Compositing

In the daily human life and production of humans,the leakage of various toxic and harmful gases seriously affects people’s life safety,and semiconductor gas sensor technology has been widely used in the field of real-time monitoring and detection of these gases.Among them,cobaltosic oxide（Co₃O₄）has attracted the attention of scholars from all walks of life in recent years for its excellent physicochemical properties.This paper is mainly focus on enhancing gas sensing properties of Co₃O₄by morphology controlling and material compositing.The main work contents of this thesis are as follows:（1）Three different nanostructures of Co₃O₄ were synthesized by using different raw materials,the morphology of Co₃O₄is nanosheets,nanocube and nanochain,respectively.The morphological structure characterization and gas sensitivity properties of three materials were tested,through the analysis of testing results,the more promising materials,Co₃O₄nanosheets,were selected for composite.（2）The synthesis of Co₃O₄/NiO nanocomplexes were performed through hydrothermal method.It is shown that the composites can improve the gas sensitivity of the sensor after analyzing the various representations and test results.Meanwhile,the effect of different concentrations of NiO on the gas sensitivity properties of composite materials are also explored.Furthermore,a suitable ratio of Co₃O₄/Ni O composites in H₂S detection and a possible sensing mechanism are provided.（3）A self-stacked structure of Co（OH）₂/Co₃O₄ nanosheets were prepared by one-step hydrothermal method.This material-based gas sensor has excellent selectivity and sensitivity for n-butyl alcohol detection.The structure and morphology of materials were characterized by using X-ray diffraction,scanning and transmission electron microscopy.The possible mechanism was discussed by combining the analysis of X-ray photoelectron spectroscopy and fourier transform infrared spectroscopy.This paper takes Co₃O₄ as the main body,explores the various methods that can enhance the gas sensitivity performance of the Co₃O₄-based sensor,and confirms that the regulation of micromorphology and composite materials can enhance the material sensitive characteristics of Co₃O₄.