三维尺寸可控六方氮化硼/石墨烯平面异质结的构建及其性能研究

The non-metallic planar heterostructure, typically represented by hexagonal boron nitride (h-BN) /graphene planar heterostructure, is widely used to modify the physical and chemical properties of materials due to its unique electronic structure. Traditional h-BN graphene planar heterostructures in two-dimensional materials are restricted by the dimension and yield, which limits the study of properties and applications of planar heterostructures. In this project, graphene is used as the initial material, and h-BN crystal is expitaxially grown along with the edge of edge-functionalized graphene to construct a three-dimensional h-BN/graphene composite containing rich h-BN/graphene planar heterostructures. The structure-activity relationship between structure and physical-chemical properties of planar heterostructures such as magnetism, thermal conductivity, semiconductor, is researched by regulating the growth factors such as temperature and atmosphere. Based on the controllable physical-chemical properties, the obtained 3D materials are applied to the field of catalysis, especially the common thermalcatalytic or electrocatalytic reactions, and the structure-activity relationship and catalytic mechanism between catalytic properties and planar heterostructures are explored. This project not only proposes a controllable preparation method for constructing 3D h-BN/graphene planar heterostructure, but also will innovatively clarify the internal relationship between planar heterostructures and catalytic activity, which provides theoretical basis for promoting the catalytic application of non-metallic planar heterostructures.

以六方氮化硼/石墨烯平面异质结为代表的非金属平面异质结，由于具有独特的电子结构，广泛用于材料的物理、化学性能改性。传统六方氮化硼/石墨烯平面异质结受到二维材料维数及产量的影响，限制了平面异质结的性能及应用研究。本项目以石墨烯为初始材料，通过对石墨烯的边缘进行官能化，外延生长六方氮化硼晶体结构，以构建具有三维结构的、包含丰富六方氮化硼/石墨烯平面异质结的复合材料。通过对平面异质结的生长因素调控，如温度、气氛等，研究异质结的结构与物理化学性能，如磁性、导热性、半导体性等，之间的构效关系。基于可调控的物理化学性能，将材料用于催化研究，特别是常见的热催化、电催化反应，探究催化性能与异质结的构效关系及催化机理。本项目不仅提出构建三维六方氮化硼/石墨烯平面异质结的可控制备方法，且将创新性地阐明平面异质结与催化活性的内在联系，为推进非金属平面异质结在催化领域的应用提供理论基础。

非金属平面异质结由于具有独特的电子结构，广泛用于材料的半导体改性。传统六方形氮化硼/石墨烯平面异质结受到制备方法和含量的影响，限制了平面异质结在多个领域的性能及应用研究。本项目通过原位生长石墨烯或六方形氮化硼（h-BN），构建h-BN/石墨烯平面异质结或垂直异质结丰富的三维多孔材料，并将异质结材料应用到电催化氧还原反应或CO2还原反应。以h-BN量子点或多孔h-BN为初始材料，通过机械化学反应将碳前驱接枝到h-BN前驱边缘，后通过水热或退火过程成功制备出平面异质结。通过在多孔h-BN表面原位生长石墨烯量子点，成功构建h-BN/石墨烯垂直异质结。通过改变前驱体含量及比例，调节异质结的尺寸及含量。通过电催化2e-氧还原反应产生H2O2过程，证实了平面或垂直异质结在电催化领域的应用前景；同时通过密度泛函理论研究，探究了异质结区域不同原子的电子云密度变化，揭示了异质结与催化性能之间的相互作用机制。另外，进一步降低h-BN掺杂尺寸，以B-N共价键的形式掺杂入碳骨架中，通过理论计算和催化性能测试，揭示了B-N活性位点催化4e-氧还原反应及电催化CO2产生CH4的作用机制。以上研究工作，为碳材料的电化学改性提供了新的研究思路。在此过程中，申请人依托该项目以第一作者或者通讯作者共计发表SCI论文7篇(其中1区4篇，其中影响因子＞20的3篇，其中1篇发表在材料领域顶级期刊Advanced materials)。申报发明专利3项。合作培养了研究生4名。超额完成了发表2-4篇学术论文、申请国家发明专利2-3项的研究计划。