三维多金属氧酸盐/石墨烯气凝胶作为高效可回收的油水分离吸收剂

A three-dimensional polyoxometalate/graphene aerogel as a highly efficient and recyclable absorbent for oil/water separation

三维石墨烯气凝胶具有可调控的孔结构、大的比表面积、优异的压缩性、弹性和润湿性,是一种高效的油水分离吸附剂。然而,三维石墨烯气凝胶的制备方法通常包括高温过程,导致高成本、能耗高和耗时长。本文以磷钼酸为交联剂和促进剂,水合肼为还原剂,在室温条件下同时将氧化石墨烯还原与自组装,制备出三维多孔的多金属氧酸盐复合石墨烯气凝胶(POM-GA),并证明其是一种高效、可回收的油水分离吸收剂。研究表明,POM-GA具有三维连通的多孔结构、大的比表面积、优异的压缩性、弹性和润湿性,对不同的有机溶剂具有良好的吸附能力(100~210 g g^−1),可快速去除水中的各种有机污染物,优于先前报道的大多数高温合成的石墨烯基宏观组装体。经10次吸附-挤压和吸附-挤压-燃烧循环后,POM-GA的吸油量保持率分别达到96%和90%。因此,三维POM-GA具有广泛的适用性和优异的耐用性,在高效油水分离方面具有良好的应用前景。

Three-dimensional(3D)graphene aerogels(GAs)with a tunable pore structure,a highly accessible surface area,and exceptional compressibility,elasticity and wettability have been explored as promising absorbents for efficient oil/water separation.However,the strategies for assembling 3D GAs usually involve a high-temperature process,resulting in high cost.We report the synthesis of a 3D porous polyoxometalate(POM)-hybridized GA(POM-GA)as a highly efficient and recyclable absorbent for oil/water separation.The material was fabricated at room temperature by the self-assembly and reduction of graphene oxide using POM as a functional cross-linker and hydrazine hydrate as a reductant.It had a 3D interconnected macroporous structure,a large specific surface area,and exceptional compressibility,elasticity and wettability,and had excellent absorption capacities of 100-210 g g^−1 for the rapid removal of various organic pollutants from water,outperforming most of the previously reported graphene-based macro-assemblies synthesized at high temperatures.Moreover,the absorbed oils can be readily removed by squeezing or first squeezing and then burning the remaining organic from the 3D POM-GA.The oil-absorption capacity retention rates of the 3D POM-GA are 96 and 90%after 10 absorbing-squeezing and absorbing-squeezing-burning cycles,respectively.The material therefore has great potential for efficient oil/water separation with wide applicability and excellent durability.