Photocatalytic Degradation of Methyl Orange by Ni2+-Doped Anatase TiO2/CoFe2O4 Composites Under Solar Light Irradiation

Abstract

Ni²⁺-doped anatase TiO₂/CoFe₂O₄ (Ni²⁺-TiO₂/CoFe₂O₄) composites with core-shell structure were prepared by an ultrasonic method. The core CoFe₂O₄ nanoparticles were synthesized via coprecipitation method and the photoactive shell Ni²⁺-doped TiO₂ nanoparticles were directly coated on the CoFe₂O₄ by the ultrasonic-induced hydrolysis reaction of tetrabutyl titanate in a nickel(II) sulfate aqueous solution, then the composites were calcined at different temperature. The resultant Ni²⁺-TiO₂/CoFe₂O₄ composites exhibited good magnetic response. The photocatalytic activities of Ni²⁺-TiO₂/CoFe₂O₄ composites were evaluated by the photocatalytic degradation of methyl orange under solar light irradiation. The results showed that Ni-doping concentration and calcined temperature had effect on the photocatalytic activities of Ni²⁺-TiO₂/CoFe₂O₄ composites. Ni²⁺ doping effectively improved photocatalytic activities of TiO₂/CoFe₂O₄ composites and the photocatalytic activities of Ni²⁺-TiO₂/CoFe₂O₄ with an optimal doping concentration of 1.5 % were four times that of undoped TiO₂/CoFe₂O₄ . Moreover, H₂O₂ assisted Ni²⁺-TiO₂/CoFe₂O₄ composites under solar light irradiation was an effective and promising process for decolourization of dye-containing wastewater.