Visible light driven and magnetically separable high performance photocatalyst CuFe0.9Ti0.1O2/GO

Abstract

This paper presents a practical, reusable and stable photocatalyst, CuFe0.9Ti0.1O2/GO, for the degradation of toxic organic dyes in water. The photocatalyst is visible light-driven, and magnetically separable which makes the photocatalyst unique and novel. The photocatalyst was successfully synthesized by a sonochemical method and post-treated with microwaves. Characterization techniques like XRD, FTIR, SEM, DRS, Raman, and VSM were used to ascertain its phase and composition, morphology, bandgap, and magnetic properties. X-ray diffraction (XRD) confirmed the phase and composition of these materials. Further, it has been observed from the characteristic peaks of XRD that Ti+4 ions have been effectively incorporated into parent material CuFeO2 with little variations due to close ionic radii of Fe+3 and Ti+4 ions. Diffusive Reflectance Spectroscopy (DRS) was used to observe the absorption spectra, and the energy bandgap was calculated using Kubelka – Munk (KM) model. The indirect energy band gap was found to be 3.02, 2.72, 2.88 eV for pure, Ti-doped and GO based CuFeO2, respectively. Pure CuFeO2 delafossite system shows ferromagnetic behavior, which is due to the magnetic spins present in the system. Ti-doped and GO based samples also show ferromagnetic behavior but with some lower saturation magnetization values. The saturation magnetizations of pure, Ti-doped and GO based CuFeO2 samples were measured to be 28.29, 17.43, 15.36 emu g−1 at 5 K and 25.01, 14.76, 12.48 emu g−1 at 300 K respectively. The material's photocatalytic activity was defined by observing the UV–visible absorption spectra of MB dye with exposure to light. The results show that the intensity of the absorption peaks of MB decreases with the increase in the exposure time of the solution in visible light, indicating the complete degradation of MB dye within 36 min. The reaction rate constant k for the photocatalyst was found to be 0.168 min−1 proving the photocatalyst to be effective and practical for potential applications.