氧化石墨烯表面/界面特性的激光调控及其气敏性质研究

Wearable and real-time gas analysis requires the gas sensors to achieve a high sensitivity at room temperature. Graphene exhibits good properties of gas sensing and flexibility at room temperature, providing new ideas for gas sensors. Interaction between intrinsic graphene and gas molecules is weak, in contrast, the surface of graphene oxide contains a large number of chemically active defects, showing remarkably improved in adsorption capacity and large-scale preparation. However, it’s hard to controll the species and distribution of defects on graphene oxide surface, and the surface area is reduced due to the sheet stacking, which seriously restrict the development of graphene gas sensor. This project proposed a new idea on the regulation of surface/interface characteristics of graphene oxide using laser micro-nanofabrication technology, to build a high specific surface area of micro- nanostructures and fabricate graphene-based gas sensor. Through the first-principle study, the mechanism of laser regulation of defect structure is explained，and the mechanism of interaction between defects and gas is clarified, graphene sensing materials are developed to meet the requirements of gas detection, laying a research foundation of the preparation of graphene gas sensor.

可穿戴的实时气体分析要求气体传感器可实现室温下的高灵敏度检测。石墨烯在室温下就表现出良好的气体传感性质和柔韧性,为气体传感器件提供新思路。本征石墨烯与气体分子之间的相互作用力较弱，与此相比，氧化石墨烯表面含有大量具有化学活性缺陷，在吸附能力和大规模制备两大方面显示出飞跃性提高。然而氧化石墨烯表面缺陷种类和分布的可控性差，以及片层堆垛引起比表面积减小，严重地制约了石墨烯气体传感器的研制。本项目提出采用激光微纳加工技术对氧化石墨烯的表面、界面特性进行调控，构建高比表面积微纳结构，制备石墨烯气体传感器的新思路。通过第一性原理，研究激光调控缺陷结构的机理，明确缺陷与检测气体的相互作用机制，探索氧化石墨烯缺陷调控和微纳结构化的核心工艺，研制满足气体检测要求的石墨烯传感材料，为石墨烯气体传感器的制备奠定一定的研究基础。

本课题主要采用纳秒激光双光束干涉还原氧化石墨烯（GO）制备气敏器件，提出了一种利用激光微纳加工技术对氧化石墨烯表面特性进行改性的方法，建立了高比表面积的微纳结构，并制备了二氧化氮传感器，采用第一性原理进一步解释了器件响应恢复性能的机制，通过激光干涉的方法，增大了薄膜的比表面积，进而提高了器件对二氧化氮气体的灵敏度，同时降低了响应和恢复时间；研究了纳秒激光双光束干涉制备还原氧化石墨烯（RGO）对乙醇气体的传感性能，第一性原理研究乙醇分子与石墨烯，环氧基团以及羟基修饰的石墨烯之间的相互作用；研究了纳秒激光作用下的还原和氮原子掺杂，证实了纳秒激光加工对氮原子引入的可行性，研究了掺杂对材料组分和电学性能的影响；此外还利用纳秒激光辐照制备GO/RGO复合水凝胶的热敏驱动器，在紫外激光照射下，制备非均匀的GO/RGO复合水凝胶，系统研究了非均匀水凝胶呈现出的各向异性。