利用低温STM研究半金属表面的水吸附及单层冰的生长动力学

水是自然界最常见的物质之一，水-固界面无处不在，与工业、科技和日常生活的诸多方面息息相关。但到目前为止，人们在分子尺度上对水与固体表面相互作用的认识仍较浅显，尤其是水与固体表面相互作用规律以及固体表面上水纳米结构的生长动力学等问题有待进一步研究。本项目将围绕这个问题，利用变温沉积技术在半金属表面制备不同维度的水纳米结构（如零维纳米团簇、一维水链和二维冰结构），结合超高真空低温扫描隧道显微镜和第一原理计算方法，识别结构中水的吸附方式和氢键构型，观察水分子和团簇的内部结构和电子密度分布，探测水团簇中质子协同量子隧穿这一氢键动力学过程。藉此探究半金属表面水纳米结构的生长动力学行为，总结水分子与衬底的相互作用、衬底温度对固体表面水纳米结构的影响，揭示水与半金属表面相互作用的一般规律。本项目的实施可为光分解水制氢、治理环境污染以及界面上水与生物分子相互作用等科学问题提供理论指导。

It is generally known that water is one of the most common substance in nature. Water-solid interfaces are ubiquitous and of the utmost importance to industry, technology and many aspects of daily life. However, our molecular-scale understanding of the water-solid interface interactions still remains incomplete to date. The law of water-solid interface interactions and the growth kinetics of water nanostructures on a solid surface also require further investigation. This project will focus on water nanostructures(0D nanoclusters, 1D molecular chains and 2D ice layers) which are prepared by variable-temperature deposition method on the semi-metallic surface. Ultra-high vacuum low temperature scanning tunneling microscopy and first principles calculation method will be utilized to identified the molecular adsorption and H bonded network, detect the internal structure, molecular orbitals and the concerted proton tunneling. In the way, the kinetics of water nanostructures grown on semi-metallic surfaces, the effects of water-substrate interaction and substance temperature on water nanostructures, as well as the general rule of water-semimetal interactions will be revealed. The implementation of this program will provide a theoretic guide for some scientific issues such as the production of hydrogen through photochemical water splitting, controlling environment pollution, the interfacial interaction between water and biomolecule, etc.