一种新型石墨烯-粉煤灰基地质聚合物复合材料的制备及光催化应用

二维石墨烯优异的理论电子迁移率,为石墨烯与粉煤灰地质聚合物的复合以及半导体光生电子的传输提供了理论依据.本工作首次报道了石墨烯-粉煤灰基地质聚合物复合光催化材料的制备,并将其应用于光催化染料降解的探索性研究.XRD、FESEM、XPS及FT-IR结果表明:粉煤灰颗粒与碱性激发剂反应,生成Si-O-Si(Al)无定形网络结构的石墨烯-粉煤灰基地质聚合物复合材料,Co2+掺杂的Fe2O3以无定形态均匀地分布于石墨烯-粉煤灰基地质聚合物复合材料表面.Co2+-10Fe2O3-GAFG复合材料对碱性品蓝染料展现出最高的光催化降解活性,归因于Co2+掺杂提供给Fe2O3半导体的施主能级,石墨烯对Fe2O3光生电子的快速传输,以及羟基自由基(·OH)对染料分子氧化降解的协同作用.该光催化降解反应符合二级反应动力学.

Synthesis of a Novel Graphene Fly-ash-based Geopolymer Composite and Its Photocatalytic Application

Two-dimensional graphene with excellent theoretical electron mobility provides a theoretical foundation for the composite of graphene and fly ash geopolymer as well as the photo-generated electron transmission of semiconductor.The graphene fly-ash-based geopolymer composite was firstly synthesized and applied as photocatalyst for degradation of dye.XRD, FESEM, XPS and FT-IR results showed that the spherical fly ash particles reacted with alkali-activated agent to generate the graphene alkali-activated fly-ash-based geopolymer (GAFG) which was composed of Si-O-Si (Al) amorphous net structure, and the lamellate graphene was wrapped inside.The fact that the Co-10Fe2O3-GAFG sample displayed the highest photocatalytic activity for degradation of basic blue dye was ascribed to the synergistic effect of: the donor level of Fe2O3 semiconductor induced by Co02+ doping, the rapid photoelectron transfer from Fe2O3 semiconductor to graphene, and the oxidative degradation of dye molecules by hydroxyl radicals.The photocatalytic degradation reaction coincides with the second-order reaction kinetics.