应用先进光谱技术研究无机离子的环境界面化学

Towards A Molecular Scale Understanding of the Chemistry of Inorganic Ions at Environmental Interfaces:Application of Spectroscopic Techniques

发生在环境界面的吸附-解吸和氧化-还原等反应对于污染物在环境介质间传输、转化以及归趋起着重要的调控作用。传统的研究方法虽然可以在实验室模拟并进而描述污染物环境界面过程,但是不能揭示界面反应机制,限制了对污染物环境界面行为的认识。近二十年来,各种谱学技术(例如X射线吸收精细结构和傅里叶红外光谱等)应用于环境界面反应的研究,推动了这一领域研究的发展,特别是在分子水平研究污染物的环境界面过程。通过现代光/波谱技术原位分析,可以实时获取界面反应的定量与结构信息,从而更准确地判断反应机制,极大促进了对污染物在多介质环境界面迁移转化规律的认识。本文将在概述环境界面化学反应的基础上,针对无机离子在环境界面的反应过程,重点介绍几种关键光/波谱技术(X射线吸收精细结构光谱、傅里叶红外光谱、拉曼光谱、核磁共振谱和穆斯堡尔谱等)在环境界面化学研究中的应用,并展望其在环境界面过程研究中的应用前景。

Environmental interfacial reactions such as adsorption-desorption and oxidation-reduction are of vital importance in controlling the transportation,transformation and fate of pollutants.Traditional macroscopic studies have well modeled and described those environmental interfacial behaviors,but can not reveal the reaction mechanisms,such that the chemical behaviors of pollutants in natural environment can not be predicted.With the application of spectroscopic techniques,especially X-ray absorption fine structure（XAFS） and Fourier transform infrared（FTIR） spectroscopy,molecular information has been provided to interpret the mechanisms,leading to a better understanding of environmental interfacial phenomenon.These studies are pushing the development of environmental chemistry from a macroscopic level to a molecular level.Modern spectroscopic techniques allow the in-situ and real-time investigation of the chemical reactions occurring at solid/water interface,providing both quantitative and structural information to elucidate the interfacial processes.Results from these studies largely improved the current understanding of the movement and transformation of pollutants among different environmental media（soil,air and water） and the prediction of their partitioning and transportation.This work starts a simple overview of interfacial reactions,and then focuses mainly on adsorption-desorption behavior as examples to introduce the applications of several spectroscopic techniques（i.e.XAFS,FTIR,NMR,Raman and Mssbauer）,and finally ends with a discussion of the constraints and promise of these techniques.