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

Highlights: • A high-performance catalyst NGO-TiO₂ based on adsorption and catalysis to treat organic dyes was prepared. • The mechanism of the action of modifier improving TiO₂ photocatalytic performance is more fully revealed through adsorption test and catalyst degradation of methyl orange. • The introduction of NGO not only improves the catalytic efficiency of TiO₂, but also solves the post-treatment problem of relying on adsorption to deal with pollutants. 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.