【作者】 孙永福； 高山； 郭宇桥； 谢毅；

【Author】 Yongfu Sun;Shan Gao;Yuqiao Guo;Yi Xie;Hefei National Laboratory for Physical Sciences at Microscale, University of Science &Technology of China;

【机构】 中国科学技术大学合肥微尺度物质科学国家实验室；

【摘要】 二维超薄结构因其原子级厚度而有着非常高的比表面积,其表面态对本征性质的贡献上升为与内部体态同等重要,因此表面态调制成为调控无机二维超薄结构本征物理性能的新途径。表面化学修饰方法,包括表面缺陷工程、表面结构扭曲、表面原子或基团吸附或取代等,能有效调制其电子结构,从而实现对其本征物性的调控,进一步实现二维材料在功能器件方面的广泛应用^[1]。特别是对于催化应用,由于原子级的厚度使得这类材料能够曝露出更多的内层原子,为催化反应提供了大量有效活性位点。我们利用同步辐射吸收精细结构谱、正电子湮没技术和第一性原理计算表征和理解二维超薄结构的原子结构、缺陷类型以及电子结构,并揭示其与其光催化、电催化等反应之间的构效关系,为催化性能的协同优化提供理论指导和明确实验方案^[2,3]。总之,二维超薄结构成为研究催化活性位点的理想模型体系,其本征物理性质的表面化学法调控为二维固体化学建立明确的结构-性能间的关系及高效催化应用提供了一个新的机遇。更多还原

【Abstract】 With atomic-scale thickness, 2D nanomaterials have extremely high specific surface area enabling their surface phase to be as important as bulk counterparts. Thus, chemical modification strategies are critical to engineer physical properties in 2D nanomaterials while maintaining their freestanding 2D lattice framework, which shows promising sign in electronics and energy-related devices. In this talk, we highlight the newly developed regulation strategies of surface incorporation, defect engineering, and structural modulation of inorganic 2D nanomaterials. Also, we focus on the recent progress in disclosing the factors that affect the activity of reactive sites, including characterization of atomic coordination number, structural defect and disorder as well as electronic structure in ultrathin two-dimensional materials by X-ray absorption fine structure spectroscopy, positron annihilation spectroscopy, and density-functional calculations. We also overview the well-defined correlation between atomic, defect, electronic structure variations and the photo/electro-catalytic properties of ultrathin 2D materials. Briefly, atomically-thin 2D materials provide an ideal platform to investigate the catalytically active sites, opening new opportunities for establishing clear structure-property relationship in 2D solid state chemistry.更多还原