Carbon Nano-Onions (CNOs)/TiO2 Composite Preparation and Its Photocatalytic Performance under Visible Light Irradiation

Abstract

Carbon nano-onions/titanium dioxide (CNOs/TiO2) photocatalyst was synthesized by a simple sol-gel method and characterized by the methods of X-ray diffraction (XRD), scanning electronic microscope (SEM), X-ray photoelectron spectroscopy (XPS), specific surface area (BET method), Fourier transform infrared (FTIR), thermogravimetric analysis (TG), differential scanning calorimeter (DSC), UV-Vis diffuse reflectance spectra (UV-Vis DRS), and high-performance liquid chromatography (HPLC). The photocatalytic activity of CNOs/TiO2 photocatalyst was assessed by testing the degradation rate of Rhodamine B (RhB) under visible light irradiation. The results showed that the optimum photocatalytic activity was achieved when the mass ratio of CNOs to TiO2 was 10%. The aforementioned specific CNOs/TiO2 photocatalyst resulted in a maximum RhB degradation efficiency of 78% (10 mg/L of RhB in 220 min). CNOs enhance the photocatalytic efficiency of TiO2 and improve the separation quantity of CNOs/TiO2 catalyst from aqueous media. CNOs can be used as a modification agent to develop high-performance photocatalysts for the removal of organic pollutants.