Novel CoFe2O4/CuBi2O4 heterojunction p–n semiconductor as visible‐light‐driven nanophotocatalyst for C (OH)–H bond activation

Abstract Nanosized CoFe 2 O 4 /CuBi 2 O 4 heterostructure was obtained by solvent‐free thermal processing and was characterized using a series of structural, physicochemical, and analytical techniques. The CuBi 2 O 4 and CoFe 2 O 4 nanoparticles demonstrated poor photoactivity due to their fast charge recombination and negligible visible light absorptivity, respectively. In contrast, the prepared heterojunction CoFe 2 O 4 /CuBi 2 O 4 nanocomposite consisting of an array of nanocolumns approximately 20 nm in width displayed nearly twofold higher photocatalytic activity than CoFe 2 O 4 or CuBi 2 O 4 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 CoFe 2 O 4 and CuBi 2 O 4 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.