Nanosized CoFe2O4/CuBi2O4 heterostructure was obtained by solvent-free thermal processing and was characterized using a series of structural, physicochemical, and analytical techniques. The CuBi2O4 and CoFe2O4 nanoparticles demonstrated poor photoactivity due to their fast charge recombination and negligible visible light absorptivity, respectively. In contrast, the prepared heterojunction CoFe2O4/CuBi2O4 nanocomposite consisting of an array of nanocolumns approximately 20 nm in width displayed nearly twofold higher photocatalytic activity than CoFe2O4 or CuBi2O4 nanostructures alone toward the C (OH)–H bond activation. This nanocomposite exhibits photocatalytic efficiency as high as 98% with very high stability. The increased photocatalytic reactivity could be related to the effective Z-scheme mechanism of photogenerated charge carrier separation between CoFe2O4 and CuBi2O4 in the nanocomposite, which reduces the electron–hole recombination. The results of this work provide a promising approach to the design and preparation of heterostructured photocatalysts for oxidation reactions.
