Research On BP/In₂O₃ And BP/ZnO-based Gas Sensors

Sensitive materials are an important part of gas sensors.Sensors using semiconductor metal oxides,such as ZnO,In₂O₃as sensitive materials have become hot research topics for gas sensors due to their simple preparation process,low cost,and stable gas sensing performance.Black phosphorus,a new two-dimensional material with a graphene-like structure,has become a new favorite of gas-sensitive materials due to its large specific surface area and ultra-high carrier mobility.At the same time,our research found that compounding traditional semiconductor metal oxides(ZnO,In₂O₃,etc.)with black phosphorene nanosheets can greatly improve the sensitivity of the sensor,reduce operating temperature,increase selectivity,and restore response-recover rate and long-term stability.It is of great significance to build a gas sensor with high sensitivity at room or low temperature.Frist,the liquid phase stripping method was used to successfully prepare the black phosphorene nanosheets with a thickness of only 2 to 4 layers.By exploring the effects of preparation parameters such as ultrasonic power or time,it was possible to quickly,efficiently and stably prepare high-quality black Phosphine nanosheet layer.Second,the BP-In₂O₃composite material was successfully prepared,and a high-performance NO₂sensor at room temperature was constructed.In₂O₃microrods were prepared by microwave-assisted hydrothermal method.The ultrasonically dispersed BP nanosheets were physically doped with the In₂O₃microrods.Then we studied the gas-sensitivity properties of BP-In₂O₃under different doping amounts of black phosphorus.When the BP-doping content was 1 wt%,the composites had the best gas-sensitivity for NO₂at room temperature.In addition,through X-ray photoelectron spectroscopy(XPS),Raman Spectra,and other characterization methods,the environmental stability of melanophosene in the composite was explored,and the reason of gas sensitivity after doping was analyzed.Finally,we prepared BP-ZnO composites by microwave-assisted hydrothermal method,and studied its gas-sensitive properties to formaldehyde at 140?.Using different BP nanosheets concentrations as dopants,microwave-assisted hydrothermal methods prepare BP-ZnO composite.The gas sensitivity test results show that:BP-ZnO has better gas sensitivity to formaldehyde when the doping amount of BP nanosheets is 0.8%wt.The chemical states of the elements in the composite after the combination of black phosphene and ZnO were discussed according to XPS and other methods.From the perspective of the band structure theory,the reason why the gas sensitivity of the composites after doped with black phosphene is discussed.In this study,we investigate the effects of different preparation parameters on the dispersion of melanophene nanosheets in the liquid phase stripping method.The effects of different doping methods and concentrations on the properties of traditional semiconductor metal oxide(ZnO,In₂O₃)gas-sensitive materials were discussed.It provides new ideas and research experience for the dispersion preparation of black phosphorene nanosheets and the construction of high-performance gas sensors.