Self-assembling TiO2 on aminated graphene based on adsorption and catalysis to treat organic dyes

Abstract

Aminated graphene oxide (NGO) was synthesized by condensation of graphene oxide (GO) and diethylenetriamine (DETA). Highly catalytic nanostructured NGO-TiO2 composite catalysts were self-assembled by a two-phase system of toluene and water. The crystal structure, morphology, and optical properties of the composite catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible spectrometry (UV–Vis) and so on. The degradation of methyl orange dye under simulated solar illumination was used to evaluate the performance of the composite catalysts. Though the particle size of the commercial TiO2 used in the work was larger than that synthesized in the laboratory, the NGO-TiO2 catalyst had better performance than the TiO2 and GO-TiO2 prepared in the same way, and the catalytic performance of NGO-TiO2 improved with increasing NGO loading amount in an appropriate ratio. The mechanism by which NGO improves the TiO2 performance was fully explained from a new perspective. The introduction of NGO not only improves the catalytic performance of TiO2 but also solves the posttreatment problem of relying on adsorption to deal with pollutants.