改性石墨烯气敏特性和催化性能的理论研究

In recent years, the theoretical and application studies of graphene have been made a number of important progresses. However, full use of the excellent physical and chemical properties of graphene needs to explore the new functional methods of the modified graphene and its potential application. In this project, the first-principles methods will be used to systematically discuss the electronic and magnetic structures, the transferred charges between substrates and adsorbates by the different modulation methods, such as, defect, doping, functional group modification, edge structures, hydrogenation saturation and adsorbing gas molecules. The physical mechanism for the structural stability, gas sensitive properties, surface activity and chemical modulation methods will be presented from the atomic and electronic level. The adsorption properties of gas molecules on graphene surface will be studied by the analysis of the energy, electronic structure and electronic density of states, aiming to explore the reaction mechanism for the sensitivity and selectivity of graphene-based gas sensor. The further research about the catalytic properties and catalytic reaction mechanism of the modified graphene can seek the key factors in the reaction rate and pathways, and clarify the relationship between the modulation ways and the catalytic property of modified graphene. The results are expected to provide a theoretical guidance for the functionalized design and applications of graphene nanomaterials.

近年来，对石墨烯理论和应用的研究已经取得了许多重要的进展，但要充分利用其优异的物理化学性能还需进一步探索改性石墨烯的功能和潜在的应用。本项目拟采用第一性原理计算方法系统研究本征缺陷、掺杂、官能团修饰、边缘结构、加氢饱和、气体分子吸附等对石墨烯的电子结构、磁性和电荷转移等性质的调制。从原子和电子层次揭示各类调制石墨烯体系的结构稳定性、气敏特性和表面反应活性的物理机制。从体系的能量、电子结构和电荷密度分布等方面研究气体小分子在石墨烯表面吸附特性及其对石墨烯电子结构的作用，探讨影响石墨烯基气敏器件的灵敏度和选择性的规律及其作用机理。进一步研究改性石墨烯的催化性能和催化反应机制，找到影响反应速率和反应途径的因素，阐明不同调制方式与其表面催化性能的关系。以期为石墨烯纳米材料的功能化设计和应用提供理论依据。

石墨烯具有优异的物理和化学特性，对其理论和应用研究取得了许多重要进展，将在新型超导材料、微电子、表面修饰和催化等方面具有良好的应用前景。为了探索石墨烯基材料的功能性，本项目从原子层次和电子结构方面探讨不同化学修饰方式对其结构稳定性和表面反应活性的调制机理。比较不同金属（Pt, Fe, Ni, Al, Mo等）、非金属原子（Si, B, N, O, P等）掺杂、官能团修饰（环氧基、羟基等）、外在电场和金属衬底等方式对体系的原子、电子结构和磁性变化的影响、以及系统地研究改性石墨烯对不同气体分子（H2S, CH4, NO, SO2, NO2, HCN, NH3等）的灵敏度、选择性等气敏特性的反应机理。最后，通过模拟化学反应过程中不同气体分子间（CO和O2、CHx和H2等）的相互作用及其中间产物(CO3, OOCO, CH3, CH2, CH, C, SH, S等)的吸附特性，探究不同调控方式对化学反应途径和反应速率的影响，以期对改性石墨烯器件在气敏、催化等方面的应用有较全面了解，为改性石墨烯及其复合材料的功能化设计和应用提供有益的理论依据。