Two-dimensional functionalized graphene oxide anchored TPA: H3PW12O40 and their application for reduction of organic dyes

This research focuses on noncovalent functionalization of two-dimensional graphene oxide. 2D geraphene oxide with controllable surface coverage and evenly distributedcomponents on the surface is desirable for developing new supports for catalysts [1- 2]. For preparation of 2D- geraphene oxide, polyvinylpyrrolidone (PVP) was used toeffectively solved incompatibility and aggregation problems between GO and inorganic media and played an important role in the two-dimensional combination of GO [3]. In the following, the surface of 2D-GO functionalized with (3- Chloropropyl)triethoxysilane and N,N-dimethylbiguanide (Metformin) respectively. Finally, phosphotungstic acid immobilized on Metformin-grafted 2D-GO as acid/base bifunctional catalyst. The catalytic behavior of the prepared catalyst was investigated for the reduction of 4-nitrophenol, methylene blue and methyl orange in the presence of NaBH4 as a reducing reagent at room temperature in aqueous media. The reaction was monitored easily by measuring the change in UV–Vis absorbance. The catalyst exhibited high catalytic performance without significantly reduction activity even after running ten cycles.