Preparation Of G-C₃N₄/MO?ZnO Based,Co₃O₄? Composites And Their Gas-sensing Properties

With the progress of urbanization,the home improvement market and the automotive decoration field continue to develop,and while bringing people a comfortable life,various problems have also come one after another.Volatile organic compounds?VOCs?in the decoration materials are very harmful to the human body,especially in indoor and in-vehicle environmental pollution.And the VOC concentration is likely to exceed the standard for not sufficiently circulated,which is more harmful to the human body.Therefore,it is of great significance to effectively detect VOCs.In this paper,metal oxide ZnO,Co₃O₄,CuO-ZnO heterojunction and semiconductor graphite phase carbon nitride?g-C₃N₄?are compounded in order to obtain excellent gas-sensing materials,and gas sensitivity properties of the prepared materials are studied.The specific research content and experimental results are as follows:?1?Graphite phase carbon nitride was successfully prepared by using thermal decomposition method.The characterization results show that the prepared graphite phase has fewer carbon nitride layers and is transparent wrinkles.It contains a highly delocalized?-conjugated system,which makes the graphite phase carbon nitride with a good stability and provides favorable conditions for composite metal semiconductor oxides.One-step hydrothermal synthesis method was used to prepare cocoon-like ZnO nanorods and cocoon-like g-C₃N₄/ZnO nanocomposites.The cocoon-like nanorods were 30-50nm in diameter and 200-300nm in length.The cocoon-like ZnO nanorods were compared and studied.Gas sensing properties of g-C₃N₄/ZnO Nanocomposites.Compared with single-component materials,the gas-sensing properties of silkworm g-C3N4/ZnO nanocomposites exhibited lower optimal operating temperatures and higher response values at optimum operating temperatures.In this study,we explain the gas sensing mechanism of the composites.?2?Co₃O₄ and g-C₃N₄/Co₃O₄ composites were prepared by a simple hydrothermal method.The gas sensitivity of Co₃O₄ and g-C₃N₄/Co₃O₄ composites were studied.Compared with single-component materials,the gas-sensing properties of g-C₃N₄/Co₃O₄ composites exhibit higher response values,shorter response-recovery time,excellent repeatability and stability,and high selectivity to ethanol.?3?Hydrothermal synthesis method was used to prepare CuO nanosheets,ZnO nanoparticles,CuO-ZnO nanocomposites,and g-C₃N₄/CuO-ZnO nanocomposites.The gas-sensing properties of CuO,ZnO,CuO-ZnO,and g-C₃N₄/CuO-ZnO nanocomposites were studied comparatively.The gas sensitivity of CuO-ZnO compare to CuO was greatly improved.This is mainly due to the formation of CuO-ZnO heterojunctions.The gas sensitivity of g-C₃N₄/CuO-ZnO compare to CuO-ZnO is greatly improved,mainly due to the synergistic effect of g-C₃N₄.