Efficient visible light photocatalytic activity based on magnetic graphene oxide decorated ZnO/NiO

ZnO/NiO/magnetic graphene oxide (ZNMG) nanocomposite has been successfully synthesized by depositing a ZnO/NiO on magnetic graphene oxide (MGo) sheets. The nanocomposite was characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopy that indicate a good combination between MGo ZnO, NiO. For ZNMG, the band gap energy of 2.8 eV was determined by the diffuse reflectance spectroscopy (DRS) that it could have appropriate potential for photocatlytic activity under visible light irradiation. Enhanced photocatalytic performance was displayed for ZNMG in removal of Congo Red (CR) dye under visible light irradiation in comparison with pure ZnO/NiO, ZnO and NiO that attributed to the increased light absorption range and the decline of electron-hole pair recombination in ZnO with formation p-n hetrojunction ZNMG. Effects of pH of solution, dosage of NiO and temperature on photocatalytic activity were investigated. Possible mechanism of ZNMG nanocomposite for photodegradation of CR under visible light irradiation was presented.