Mechanochemical establishment of CuBi2O4/Zn-Al LDH p-n heterogeneous junction for effectively promoted bisphenol A photodegradation under visible-light driven

A noble metal-free CuBi2O4/Zn-Al LDH p-n junction hybrids with built-in electric field were facile synthesized through a mechanochemical pathway. The phase composition, micromorphology, crystal structure, electrochemical properties and DFT theoretical calculation of the as-synthesized materials were fully qualitatively investigated. Quantitatively, 10 wt%CuBi2O4/LDH sample exhibited the most performed visible-light driven photocatalytic activity on bisphenol A (84 %, 240 min), with a reaction rate constant over 4.7 and 2.5 times higher than that of pristine LDH and CuBi2O4. The enhanced photocatalytic and stability can be attributed to the mechanochemical distribution of CuBi2O4 upon LDH matrix and the simultaneous fabrication of built-in electric field triggered by the p-n heterogeneous junction, which may facilitate the separation and migration of photogenerated carriers. After four cycles, neither the functional activity nor the chemical properties of the materials show significant change, confirming the considerable reusability and stability. The investigation on mechanism proved the decisive roles of·OH during the photocatalytic process.