多孔石墨烯复合材料的设计合成及其对水中污染物的吸附性能研究

The project aims to use graphene as adsorbent and remove the low concentration micro-pollutants with properties of high toxicity, hardly degradation in water. Graphene has the disadvantages such as difficult to disperse, easy to agglomerate, difficult to separate, easy to cause secondary pollution. The studies focus on functionalization of graphene, design and synthesis of multiporous graphene composites to realize the preparation of the materials with controllable physicochemical properties such as constituent, morphology, size, pore diameter, specific surface area, pore volume, numbers and species of functional groups etc. and improve the adsorption capability and removal efficiency. The project also reveals the adsorption mechanism of micro-pollutants in wastewater adsorbed by multiporous graphene composites and explores the interaction mechanism between micro-pollutants and active functional groups on the surface of graphene. The mathematic models are built to quantitatively describe and accurately predict the removal effectiveness of micro-pollutants removed by the adsorbents. The regeneration method and mechanism will be found and discussed in order to desorb the micro-pollutants from the adsorbents effectively. The studies will establish a firm theoretical foundation for practical applications of new adsorbents of graphene. It also has important guiding significance in guaranteeing the safety of drinking water and promoting the applications of graphene in environmental protection.

本项目以去除水体中低浓度、高毒性、难降解微污染物为目标，以石墨烯为研究对象，针对石墨烯在水中难分散、易团聚、难分离、易造成二次污染等若干关键科学问题，研究重点集中在功能化改性石墨烯，设计合成多孔石墨烯复合材料，实现材料组成、形状、尺寸、孔径、比表面积、孔体积、官能团数量和种类等物理化学性能的可控制备，提高其吸附能力和吸附效率；探求多孔石墨烯复合材料对水中微污染物的吸附机理，从微观层面探求微污染物与石墨烯表面活性官能团的作用机制，构建适用于定量描述和准确预测吸附剂对微污染物去除效能的数学模型；研究其再生机理，获得简单有效、经济实用的解吸附方法。这将为新型高效石墨烯吸附材料的应用奠定坚实的理论基础，对保证饮用水安全，促进石墨烯在环保领域中的应用也具有重要的指导意义。

本项目以去除水体中低浓度、高毒性、难降解微污染物为目标，以石墨烯为研究对象，针对石墨烯在水中难分散、易团聚、难分离、易造成二次污染等若干关键科学问题，通过硫化、氮化、腐殖酸、干酪素、环糊精等对氧化石墨烯进行功能化改性处理，并寻求合适的载体，利用海藻酸钠、甲壳素、纤维素、环糊精、假酸浆籽胶、桃胶等材料，设计合成多孔石墨烯复合材料，通过调控材料的成分、制备工艺等，实现多孔石墨烯复合材料组成、形状、尺寸、孔径、比表面积、孔体积、官能团数量和种类等物理化学性能的可控制备，提高其吸附能力和吸附效率。制备的海藻酸钙多孔薄膜对污染物具有良好的过滤去除性能和大的吸附容量，质量分数为1%的海藻酸钠形成的薄膜对亚甲基蓝的过滤去除率高达 84.6%，温度在288 K、亚甲基蓝溶液的平衡浓度为80 mg/L时吸附容量可以达到1679.52 mg/g。硫、氮共掺杂的还原氧化石墨烯(S-N-rGO)纳米杂化材料在溶液pH=4-10时，材料对亚甲基蓝的吸附容量从473.90 升至 479.90 mg/g，去除率达到98.73-99.98%。探求了多孔石墨烯复合材料对水中微污染物的吸附机理，从微观层面探求了微污染物与石墨烯表面活性官能团的作用机制，构建了适用于定量描述和准确预测吸附剂对微污染物去除效能的数学模型；研究了其再生机理，获得简单有效、经济实用的解吸附方法。为新型高效石墨烯吸附材料的应用奠定坚实的理论基础，对保证饮用水安全，促进石墨烯在环保领域中的应用也具有重要的指导意义。