半导体原子级厚二维晶体的制备、组装、能级调控及光解水应用

This project covers the controllable synthesis, fine structure characterization, device assembly and photochemical water splitting properties of inorganic semiconductor two-dimensional crystals with atomic thickness and their hybrid structure with graphene. Available pathways will be developed to fabricate the inorganic semiconductor two-dimensional crystals with atomic thickness, while X-ray absorption fine structure spectroscopy will be utilized to disclose the structural distortion and the unique electronic structure. Through controlling the exfoliation of the layers and fabricating the inorganic semiconductor/graphene hybrid structure, the energy level of the inorganic semiconductor two-dimensional crystals could be finely manipulated. Effective strategies will be developed to fabricate film devices of inorganic semiconductor two-dimensional crystals and their hybrid structure with graphene, and their ordered assembly mechanism will be detailedly established. Then, the photochemical water splitting properties of the inorganic semiconductor two-dimensional crystals with atomic thickness and their hybrid structure with graphene will be conducted. Based on the effective strategies for synthesizing inorganic semiconductor two-dimensional crystals with atomic thickness and first-principles calculations, an in-depth understanding of the correlations between synthesis, structure and property will be achieved, which hence provides the theoretical foundation to fabricate high-performance flexible energy devices. This project will enrich the development of two-dimensional inorganic solid chemistry, and also provides new principle and material systems for the design, assembly and applications of novel high-performance photoelectric film devices.

本项目拟以类石墨烯结构的无机半导体原子级厚二维晶体为研究对象，聚焦其在光解水领域的应用，以无机半导体二维晶体及其与石墨烯插层复合结构的制备、缺陷及精细结构表征、器件组装及光解水性能为研究主线，深入开展无机半导体原子级厚二维晶体的化学制备，利用同步辐射X射线吸收谱揭示其表面晶格的扭曲及特殊的电子结构，通过控制剥离的层数及制备无机半导体与石墨烯的插层复合二维结构实现对能级调控，并进行温和条件下的有序组装，测量基于无机半导体原子级厚二维晶体及其与石墨烯插层复合结构薄膜器件的光解水性能。在建立系列无机半导体原子级厚二维晶体制备方法的基础上，结合理论计算，将对高效光解水材料的合成-结构-性能三者之间的关系形成一些本质的理论认识，进而为组装构筑系列高性能柔性能源器件提供理论基础。本项目的实施将丰富和发展二维无机固体化学，同时也为新型高性能薄膜光电器件的设计、组装和应用提供新原理和新材料体系。

本项目在实施过程中发展了多种制备无机半导体超薄二维晶体的普适性方法如层状杂化中间体辅助法、取代固溶体剥离法和插锂-脱锂剥离法以及直接液相剥离法等，实现了无机超薄二维晶体的可控制备，大大拓展了无机超薄二维晶体的种类；利用同步辐射X射线吸收谱解析了无机超薄二维晶体的原子结构和配位环境，解决了利用常规物相表征手段无法解决的瓶颈问题；利用正电子湮没谱和球差校正的电子显微镜等解析了无机超薄二维晶体中缺陷的种类以及浓度等信息；利用理论计算研究了缺陷工程和表面修饰等对无机超薄二维晶体电子结构的影响，揭示了超薄二维材料独特的电子态；利用超快时间分辨光谱、表面光电压谱和原位IR光谱等技术系统研究了本征缺陷、掺杂、合金化等方式对超薄二维晶体光电催化性能的影响规律。以上有关工作超额完成项目任务书的研究内容，共在Nature、 Nature Commun.、J. Am. Chem. Soc.、 Angew. Chem. Int. Ed.、Adv. Mater.等国际顶级刊物上发表94篇SCI论文。受邀为Acc. Chem. Res., Chem. Soc. Rev., Materials Today, ACS nano, Adv. Mater., Materials Science & Engineering R, ACS Energy Lett., Nano Today撰写综述，相关工作被Nature Energy和Chemistry World等杂志作为亮点论文进行了报道，部分工作入选《中国科学十大进展》。