改性三维网状石墨烯水凝胶的可控制备及铀吸附性能研究

In order to solve the shortage of uranium resources in China, this project aims at studying the extraction and separation of uranium from seawater. Adsorption is one of the most important methods for extracting uranium from seawater. The disadvantages of the existing adsorbents, such as small specific surface area, difficult separation process and poor selectivity, limit their further application to remove uranium from seawater. Herein, a modified graphene hydrogel with three-dimensional (3D) network structure was used to adsorb uranyl ions in seawater. Based on the controllable preparation of the graphene hydrogels, amidoxime groups with high selectivity and graphene hydrogel were used to prepare functional graphene hydrogels. By designing the functional adsorbent with three-dimensional network, the performance is effectively improved and the problem of difficult separation and poor selectivity is efficiently solved. The effect of structure and morphology to the adsorption of uranium was comprehensively explored. In addition, the parameters affecting the adsorption process, the thermodynamics and kinetics were carefully discussed. The adsorption performance in simulated seawater was also investigated. This work provides fundamental research and theoretical guidance for the preparation of graphene hydrogel and application to extract uranium from seawater, which is of great significance for the development of China's energy industry.

本项目针对我国陆地铀资源的短缺，开展海水中铀的提取与分离研究。吸附法是海水提铀的一种重要手段，现有的吸附剂由于比表面积小，吸附分离难，选择性差等缺点，限制了其在海水提铀中的应用。本项目拟采用改性三维网状结构石墨烯水凝胶来吸附海水中的铀酰离子。基于对三维网状石墨烯水凝胶的可控制备，选择对铀有高选择性的偕胺肟材料与石墨烯水凝胶复合，制备功能化的石墨烯水凝胶复合材料。通过设计功能化三维网状结构吸附剂，有效地改善了吸附剂性能，解决吸附剂吸附分离难和选择性差的问题。本项目系统研究吸附剂的结构、形貌对铀吸附性能的影响，以及溶液的pH值、吸附时间、吸附温度等条件对铀吸附性能的影响，验证吸附剂在吸附过程中的热力学模型、动力学模型；考察在模拟海水中吸附剂的铀吸附性能，为石墨烯水凝胶复合材料的制备及在海水提铀中的应用提供基础性研究及理论指导，对于我国能源事业的发展具有重大意义。

针对我国陆地铀资源的短缺，本项目开展了海水中铀的提取与分离研究。研究了三维网状石墨烯水凝胶构筑方法，完成了三维网状石墨烯水凝胶改性研究工作，并通过红外、元素分析、X-射线衍射、扫描电子显微镜、透射电子显微镜等手段表征。设计多个改性石墨烯水凝胶体系，考察了反应条件，模板剂、结构助剂、反应溶剂对吸附材料孔径结构的影响。系统研究了PEI改性石墨烯复合材料对铀的吸附性能，用改性石墨烯复合材料在不同吸附温度下的实验数据，计算出相关的热力学参数，并验证了其吸附模型。考察了在模拟海水中吸附剂的铀吸附性能，为石墨烯复合材料在海水提铀中的应用提供理论依据。在基金委的大力扶持与资助下，团队成员的共同努力下，本项目取得一些可喜的成果，累计发表SCI论文21篇，授权相关发明专利1项，培养硕士和博士研究生多人，项目成员获得了较好的发展，项目负责人入选黑龙江省博后英才计划和获得黑龙江省高校科学技术二等奖。