Easy and cost-efficient modifications of titanium dioxide nanoparticles that improve their efficiency in the visible light domain represent a continuous and challenging research topic. In addition, the effect of graphene on the overall photocatalytic process is still debated. Consequently, herein, we prepared a series of TiO2 nanoparticle-based composites with different copper oxide mass content (1-3%) and co-doped with graphene of different oxidation degrees. Different characterization techniques were used to analyze the structural and physico-chemical properties of the obtained composites: Scanning Electron Microscopy (SEM)/Transmission Electron Microscopy (TEM)/Energy-dispersive X-ray spectroscopy (EDX) analysis, X-ray powder diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The photocatalytic performance was evaluated by the degradation of methylene blue under both UVA and visible light irradiation. The nanocomposites show very good photocatalytic activity independent of the presence of reduced graphene oxide, due to the Cu2O/CuO-TiO2 heterojunctions. This finding has been confirmed by the very efficient visible-light-driven degradation of amoxicillin and ciprofloxacin.
Keywords: Cu2O/CuO-TiO2 heterojunction; copper oxides-TiO2-graphene composite; methylene blue UVA photodegradation.