基于同步辐射原位研究双金属氧化物组分、结构与砷吸附形态及转化的关联规律

Arsenic-contaminated water does great harm to human health. Recently, it is the hot issue about how to control the morphology, composition and pore structure of nanomaterials leading to the enhanced arsenic adsorption capacity. Thus, in order to design and synthesize nanomaterials with high arsenic removal performance, it is necessary to gain the law of the correlation between component, structure of adsorptive materials and the adsorbed arsenic speciation and its form transformation from the molecular level. In this program, the aim is to study the arsenic adsorption behavior on the surface of binary metal oxides, to explore the preferential adsorption sites for arsenic, to investigate the change of arsenic speciation during the process of As(III) adsorption and conversion from As(III) to As(V), and to study the dynamic change of structure of formed complexes through arsenic adsorption based on in situ synchrotron radiation. Furthermore, we eventually reveal arsenic adsorption mechanism and gain the law of the correlation between component, structure of adsorptive materials and the adsorbed arsenic speciation and its form transformation from the molecular level by the combination of the analysis of the kinetics and thermodynamics of arsenic adsorption process. The research results will provide a theoretical basis and technical support for the design and preparation of nano structured materials with high arsenic removal performance.

高砷饮用水对人体健康危害极大，近年来调控纳米材料的形貌、组分和孔结构增强砷的吸附容量是研究的热点。因此，为了设计制备高效去除砷材料，从分子层面掌握砷在吸附材料表面的吸附形态及转化规律与材料本征参数之间的关联非常必要。本项目基于同步辐射X射线线吸收光谱方法原位研究砷在双金属氧化物表面的吸附行为，探索砷在多元体系中的优先吸附位点、As(III)在双金属氧化物表面吸附氧化转化过程形态的变化以及吸附形成配合物结构动态变化规律，结合吸附动力学和热力学过程分析，从分子层面揭示双金属氧化物对砷吸附的机理以及砷吸附与材料组分、结构参数的关联规律，为设计制备高效的去砷纳米结构材料提供理论基础和技术支持。

地下水砷污染是世界性的环境问题，高砷饮用水对人体健康危害极大，近年来调控纳米材料的形貌、组分和孔结构增强砷的吸附容量是研究的热点。因此，为了设计制备高效去除砷材料，从分子层面掌握砷在吸附材料表面的吸附形态及转化规律与材料本征参数之间的关联非常必要。本项目基于同步辐射X射线线吸收光谱方法研究砷在双金属氧化物表面的吸附行为，As(III)在双金属氧化物表面吸附氧化转化过程形态的变化以及吸附形成配合物结构动态变化规律。已完成的主要研究内容为：1）Ce-Zr氧化物纳米复合材料去除水中砷及机理研究；2）利用同步辐射X射线线吸收光谱方法研究了As(V)和As(III)在CeO2-ZrO2纳米空心球表面吸附行为；3）利用同步辐射X射线线吸收光谱方法研究了pH值影响下As(III)在CeO2-ZrO2纳米空心球表面吸附氧化转化的规律；4）As(III)在铁基氧化物复合材料表面吸附、氧化转化过程研究。这些研究成果将从分子层面揭示双金属氧化物对砷吸附的机理以及砷吸附与材料组分、结构参数的关联规律，为设计制备高效的去砷纳米结构材料提供理论基础和技术支持。