Fabrication of magnetically recoverable Ag/CuNb2O6/CuFe2O4 ternary heterojunction composite for highly efficient photocatalytic degradation of pollutants

Development of efficient and easily recyclable photocatalysts has aroused wide attention. Herein, we synthesized Ag/CuNb2O6/CuFe2O4 ternary heterojunction composites as efficient and easily recyclable photocatalysts. The as-synthesized photocatalysts were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-vis diffuse reflectance spectra, X-ray photoelectron spectroscopy and electrochemical measurements. Compared with CuNb2O6, Ag/CuNb2O6 and CuNb2O6/CuFe2O4, the Ag/CuNb2O6/CuFe2O4 exhibits improved photocatalytic activities of degradation methylene blue and imidacloprid under visible light irradiation. The excellent photocatalytic activity of the Ag/CuNb2O6/CuFe2O4 ternary heterojunction photocatalyst can be ascribed to the enhanced visible light absorbance region and the fast separation of photogenerated charges. It is notable that as-synthesized Ag/CuNb2O6/CuFe2O4 photocatalysts possess excellent magnetic recoverability under an external magnetic field. In addition, the photostability of Ag/CuNb2O6/CuFe2O4 was studied, and a plausible photocatalytic mechanism was proposed.