铁基合金材料对铯的吸附过程及机理研究

Cesium, with its great economic importance for industrial use, is extensively applied in various industries including power source, pigment, aerospace and other emerging fields. The total amount of cesium is huge in Salt Lake which distributes in different parts of Qinghai province. Considering the complexity of salt lake environment, it is not easy for the uptake of cesium. Therefore, the basic research related to new adsorbent, technology and process needs to be put at first place. In this study, we found that the iron-based alloy materials have excellent surface property because of elemental iron which exist in alloy materials, furthermore this kind of alloy materials can overcome erosion in salt lake, whereas the conventional theory of adsorption could not explain the mechanism of adsorption. The iron-based alloy materials are prepared through a template combined with liquid phase reduction method . The design of materials and performance are guided by XRD, TEM, SEM, BET and other analytical tools. The structure, morphology and composition of alloy materials are studied to determine the adsorption properties of Cs+. The kinetics and thermodynamics experiments are carried out to determine the adsorption process of Cs+ in iron-based alloy materials. Combined with EXAFS, XPS, we determine the combination mode of Cs+ and clarify the mechanism of adsorption. It will provide theoretical supporting for cesium uptake from salt lake.

铯在能源、航天等新兴领域具有重要的应用价值。我国青海地区分布着众多的盐湖，铯资源储量十分丰富。从盐湖复杂体系中分离回收铯资源这一科学难题决定了提取分离新材料、新技术和新方法基础性研究的重要性。研究发现，铁基合金材料中的铁保留了单质铁的性质，具有优良的界面性能，同时合金材料对Cs+具有优良的吸附性能及抗腐蚀等特性，常规的吸附理论尚不能解释其吸附机理。本研究拟采用液相还原结合模板法制备铁基合金材料，运用XRD、TEM、SEM、BET等分析手段对材料进行设计指导和性能评价；研究材料结构、形貌、组成对吸附性能的影响；开展动力学及热力学实验，确定Cs+在铁基纳米合金材料上的吸附过程；结合EXAFS、XPS分析手段，确定Cs+与合金材料的结合方式，阐明吸附作用机制，最终为盐湖分离提取铯提供理论支撑。

本项目围绕合金材料料吸附铯离子为主题，深度挖掘了合金材料的优势，围绕其可塑性，磁性以及导电性等特性进行了深入探究和功能性改造。获得了一种合金材料的普适性制备方法。通过负载活性物质，表面改性等手段制备了对铯离子具有良好吸附能力的磁性和导电性合金(金属)材料。材料具有易收集，选择性好，吸附容量大，吸附效率高等优势，特别是在电化学吸附应用方面有很广阔的应用前景。可作为一种绿色、高效、节能的新型铯离子吸附剂，为青海盐湖中的铯离子提取提供技术支持。在此基础上，开发了一种金属氧化物半导体材料合成的通用方法。发现磷源不仅实现了对半导体材料进行晶格磷掺杂，还可以对其进行形貌调控。因此，该方法对新型半导体材料制备兼具晶格掺杂与形貌塑造等双重功能，在光化学、电化学应用方面的功能得到显著提高。