Research On Co Based P-type Semiconductor Oxide Gas Sensor For Indoor Environment Detection

The living environment of human is closely related to the surrounding gases.More than80%of time indoors are spends for a person every day.To monitor toxic gases around efficiently,gas sensors emerged.Duing to the easy integration,preparation,high sensitivity and other advantages.Semiconductor oxide gas sensor extensively used.Preparing sensitive materials with excellent performance is essential.In the paper,starting from the concept towards composition and structure of p-type materials,Co₃O₄,NiCo₂O₄,Ni-Co₃O₄were controlled analysed through hydrothermal and coprecipitation method Additionally,the gas sensing properties were systematically evaluated,The concrete research contents are displayed in follows:1、By adjusting the ratio of ethanol to water,Co₃O₄samples with different structure were prepared through hydrothermal method.With the volume of ethanol to water reached 1:1,okra-like porous Co₃O₄with unique morphology was obtained.Moreover,the performance of pepared sensors based on different ratio of alcohol to water was analyzed.Compared with other samples,the okra-like Co₃O₄sensor revealed the highest response of 35.2 to100ppm acetone at 150℃.2、hierarchical flower-like NiCo₂O₄prepared through hydrothermal method,which is composed of hexagonal nanosheets,with many pores in it.The sensing performance of prepared samples were systematically tested.Compared with other samples,NiCo₂O₄with hierarchical flower-like structure displayed more excellent,sensing characteristic and can be applied to detec n-butanol at 165℃.3、Ni-Co₃O₄with hierarchical structure was synthesized by one-step coprecipitation method.Solvent-dependent experiments were implemented to analyzed the influence of alcohol/water.The sensing characteristic were evaluated,5.3mol%Ni-Co₃O₄sensor revealed the highest response（8.34）to 100 ppm n-butanol at a low optimal temperature（165℃）,and also exhibited the excellent anti-humidity ability and long-term stability.