In-situ mechanochemical fabrication of p-n Bi2MoO6/CuBi2O4 heterojunctions with efficient visible light photocatalytic performance

The fabrication of a p-n heterojunction structure is known to be a strategy for realizing efficient separation and migration of charges in photocatalysts to improve their photocatalytic activity. In this paper, a series of Bi2MoO6/CuBi2O4 p-n heterostructured photocatalysts were mechanochemically synthesized in-situ. The synthesized products were characterized by various techniques and evaluated for their photocatalytic capacities with photocatalytic degradation of ciprofloxacin under visible light irradiation, which qualitatively confirmed the synchronous formation of the binary heterojunction with matched band structure in a solid-state system. Compared with pristine Bi2MoO6 or CuBi2O4, the Bi2MoO6/CuBi2O4 p-n composites showed enhanced performance in photocatalytic degradation of ciprofloxacin (CIP), owing to the formation of p-n junctions and the subsequent enhancement in separation and migration efficiency of photogenerated carriers. Moreover, the Bi2MoO6/CuBi2O4 composites maintained good stability after four cycles of CIP photodegradation. Based on the obtained results, a possible photocatalytic mechanism for the as-synthesized Bi2MoO6/CuBi2O4 composites was proposed.