Synthesis of frost-like CuO combined graphene-TiO2 by self-assembly method and its high photocatalytic performance

Abstract

A novel material, frost-like CuO combined-graphene-TiO2 composite, was successfully synthesized using a self-assembly method. During the reaction, the loading of CuO and TiO2 nanoparticles on graphene sheets was achieved. The obtained CuO-graphene-TiO2 composite photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), Raman spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), and X-ray photoelectron spectroscopy (XPS). The frost-like CuO nanoparticles combined with the small TiO2 rods were successfully loaded on the transparent graphene sheets. The photocatalytic degradation of rhodamine B (RhB), methylene blue trihydrate (MB), and reactive black B (RBB) in an aqueous solution under visible light irradiation was observed by UV spectrophotometry after measurement of the decrease of their concentrations. Through the photocatalytic test and TOC results, the CuO-graphene-TiO2 is expected to become a new potential material for photodegradation activity with excellent photodegradation. The scavenging experiments confirmed that OH and h+ play a major role in the photocatalytic reaction than O2− or both hydroxyl and holes are the active species responsible for the RBB degradation under visible light irradiation. After five repeated cycles to investigate the stability of photocatalytic performance, the CuO-graphene-TiO2 had high stability under visible light irradiation.