MOFs基rGO-金属氧化物多孔纳米纤维的构筑、表面调控及其室温NO2气敏性能研究

针对目前金属氧化物（MO）基室温NO2传感器存在灵敏度低、响应恢复慢的问题，本项目拟以MOFs基还原氧化石墨烯-MO(如rGO-ZnO)异质结复合纳米纤维作为室温NO2气敏材料，首先通过MOFs结构的尺寸和孔隙、聚苯乙烯颗粒尺寸、纺丝退火温度和升温速率等参数调控复合纤维的孔径，研究孔径的类型、大小及数量对NO2室温响应/恢复时间的影响；通过温度、淬火、气氛等热处理条件调控复合纤维的表面缺陷，基于实验和理论计算分析缺陷的类型和浓度对NO2室温气敏性能的影响；以“团簇束流源技术”制备的超小尺寸贵金属（Ag、Pd）团簇(＜2nm)对复合纤维进行表面修饰，探究团簇修饰对NO2室温气敏性能的尺寸效应及增敏机制；最后对气敏层进行超疏水聚合物纳米纤维表面包覆，研究聚合物包覆对NO2的室温抗湿增敏机理；优化复合纤维的孔径及表面调控参数，获得高灵敏、快速响应恢复等优异的室温NO2气敏特性并揭示相关增敏机制。

In view of the main problems of low sensitivity and long response/recovery times of current metal oxide (MO) based room-temperature NO2 sensors, this project plans to use MOFs-based reduced graphene oxide-MO (such as rGO-ZnO) heterojunction composite nanofibers as room-temperature NO2 gas sensing materials. Firstly, the pore sizes of rGO-MO composite nanofibers will be modulated by controlling the parameters, such as the size and pore size of MOFs nanostructures, size of polystyrene particles, annealing temperature and heating rate during electrospinning. The influences of the type, size and quantity of pores in the composite nanofibers on the room-temperature NO2 response/recovery times of rGO-MO sensors will be deeply studied. The surface defects in rGO-MO nanofibers will be modulated by controlling the heat treatment conditions, such as temperature, quenching, and atmosphere. The influences of the defect type and concentration on the room-temperature NO2 sensing properties of rGO-MO sensors will be analyzed based on experimental and theoretical calculations. Surface modification of rGO-MO nanofibers will be carried out by ultra-small noble metal (Ag, Pd) nanoclusters (< 2 nm) prepared by a magnetron-sputtering gas-condensation cluster-beam source. The size effect and sensing enhancement mechanism of nanocluster surface modification on the room-temperature NO2 sensing properties of rGO-MO will be explored. Finally, superhydrophobic polymer nanofibers will be coated on the surface of the sensing layer, and the enhanced mechanisms of NO2 sensing properties and anti-humidity at room temperature by surface coating will be researched. The related sensing enhancement mechanisms will be revealed, and excellent room-temperature NO2 sensing properties, such as high sensitivities and short response/recovery times, will be obtained by optimizing the parameters of pores and surface regulations.