石墨烯-金属氧化物复合材料的甲醛气敏性能及敏感机理研究

The gas-sensing properties of graphene (or graphene oxide) have drawn much attention because it possesses high specific area and its conductivity is affected by the gases in atmosphere. But in the present literatures, the sensitivity of graphene (or graphene oxide) is low and the detection limit is high; the gas-sensing selectivity, the gas-sensing selectivity mechanism and gas-sensing mechanism of graphene (or graphene oxide) are rarely investigated. In this project, a series of nano-composites of graphene (or graphene oxide) -metal oxide will be prepared via hydrothermal (or solvothermal) method, the gas-sensing selectivity will be adjusted by adding metal oxide; one nano-composite material system which has high sensitivity and good selectivity to HCHO vapor will be selected from the series of nano-composite materials and will be studied in detail; the effect of preparation condition, preparation method and the composition of nano-composites on the conductivity and the gas-sensing properties (gas sensitivity, gas-sensing selectivity and stability) will be investigated; The essence law between the microstructure, the composition of nano-composites and gas-sensing stability, gas-sensing selectivity will be explored; The influence of the species and the content of metal oxide in nano-composite on the gas-sensing stability and gas-sensing selectivity of the material will be uncovered; the property-structure relation between the gas-sensing property and the microstructure, the composition of nano-composite will be uncovered; The gas-sensing reaction mechanism, gas-sensing selectivity mechanism and the gas-sensing stability mechanism of the nano-composites will be clarified.

由于石墨烯（或氧化石墨烯）有高比表面积和其导电性受到周围环境中气体的影响，因此其气敏性能受到广泛关注。但是石墨烯（或氧化石墨烯）的气敏灵敏度偏低，检出限量高；其气敏选择性、选择性机理和气敏机理极少被涉及。本项目利用水热法（或溶剂热法）制备石墨烯（或氧化石墨烯）-金属氧化物的系列纳米复合材料，通过金属氧化物来调控复合材料的气敏选择性，挑选出一种对甲醛灵敏度高、选择性好的材料体系作为重点研究对象，研究制备条件、制备方法和复合材料组成对材料的导电性能和气敏性能（重点是灵敏度、选择性和稳定性）的影响；探索复合材料的微结构、组成与气敏稳定性、选择性之间的本质规律；揭示金属氧化物种类和含量对复合材料气敏稳定性和选择性影响规律；揭示纳米复合材料微结构、组成与气敏性能之间构效关系，弄清石墨烯（或氧化石墨烯）-金属氧化物纳米复合材料的气敏反应机理、选择性机理和稳定性机理。

由于石墨烯有高比表面积和其导电性受到周围环境中气体的影响，因此其气敏性能受到广泛关注。但是石墨烯的气敏灵敏度偏低，检出限量高；本项目利用水热法（或溶剂热法）制备石墨烯-ZnFe2O4、石墨烯- CdFe2O4、石墨烯-WO3、石墨烯-Zn2SnO4、石墨烯-SnO2、石墨烯-ZnGa2O4、石墨烯量子点-SnO2、石墨烯量子点- ZnFe2O4、石墨烯量子点/α-Fe2O3、石墨烯量子点-ZnO等材料体系，通过石墨烯、石墨烯量子点的含量来调控复合材料的气敏灵敏度、气敏选择性，得到了对低浓度甲醛、三甲胺、丙酮等气体灵敏度高、选择性好的材料体系;研究了制备条件、制备方法和复合材料组成对材料的导电性能和气敏性能（重点是灵敏度、选择性和稳定性）的影响；在275 ℃的工作温度下，0.125wt%石墨烯-ZnFe2O4(180 ℃，10 h) 复合材料对应元件对低浓度丙酮气体有较好选择性；0.5 wt%石墨烯-Zn2SnO4 (200oC，24 h)复合材料对应元件在室温下可以检测低浓度甲醛；0.1 wt%G-SnO2 (100 oC，10 h)复合材料对应元件可以在不同工作温度下检测甲醛和乙醇；1 wt%石墨烯-CdFe2O4(180oC,12 h)对应元件在270oC工作温度下对0.01 ppm~1000 ppm丙酮气体；在270oC的工作温度下，GQDs -α-Fe2O3(S-15)对应元件对0.01 ppm~1000 ppm三甲胺气体。探索了复合材料的微结构、组成与气敏稳定性、选择性之间的规律；揭示了金属氧化物种类和含量对复合材料气敏稳定性和选择性影响规律；揭示纳米复合材料微结构、组成与气敏性能之间构效关系，弄清石墨烯（或氧化石墨烯）-金属氧化物纳米复合材料的气敏反应机理、选择性机理和稳定性机理。但是，材料的稳定性有待改进。