Fabrication of BiOI−C3N5 heterostructure with enhanced visible-light efficiency in photocatalytic antibiotics degradation

As a visible-light photocatalyst, bismuth iodide oxide (BiOI) is widely applied in water photocatalytic pollution degradation. However, due to the inherent high recombination rate of electron−hole pairs, an efficient photocatalytic performance could realize rarely by bare BiOI, resulting in its limited practical application. In this study, a novel type-II BiOI−C3N5 heterostructure was prepared by a feasible solvothermal method to inhibit the recombination of photoexcited electrons and holes. The photocatalytic activity of the heterostructure was evaluated by degradation of tetracycline (TC) and penicillin G sodium. The results showed that compared with bare C3N5 and BiOI, the photodegradation efficiency of tetracycline and penicillin G sodium was remarkable improved after heterostructure formation and the BiOI−C3N5 (10% wt) samples demonstrated a higher degradation efficiency. The improvement of photocatalytic degradation activities can be attributed to the formation of type-II heterostructures with a close contact. Under the synergistic effect and interface structure in BiOI−C3N5, the spatial separation and transfer of charge carriers were increased significantly, which is in favor of enhancing the photocatalytic oxidation capacity of BiOI.