[en] BiOCl nanosheets were loaded on the surface of β-Bi₂O₃ and its photocatalytic reduction activity was investigated. The composite displays excellent photocatalytic reduction activity. The NH₃ yield rate of β-Bi₂O₃/BiOCl composite is nearly 25 times as that of pure BiOCl under Xenon lamp irradiation. The β-Bi₂O₃/BiOCl heterojunction presents superior photocatalytic reduction activity for the degradation of Cr(VI) ions, and Cr(VI) ions are totally removed in 18 min. The results of photocurrent and electrochemical impedance spectroscopy measurements reveal that the formation of β-Bi₂O₃/BiOCl heterojunction contributes to reduce the recombination of the photogenerated electrons and holes. The process of photocatalytic reduction activity over composite is explained by Z-scheme mechanism.

[en] BiFeO₃/BiOCl (BFO/BOC) nanocomposite has been synthesized through a simple chemical etching method using hydrochloric acid. XRD and HRTEM results indicated that part of BiFeO₃ transformed to BiOCl, and BiFeO₃/BiOCl nanocomposite was successfully prepared. The bandgap values of the prepared BiFeO₃ and BiOCl sample are estimated to be 2.23 eV and 3.65 eV using ultraviolet–visible absorption spectra. There are two prominent photo absorption bands for the BFO/BOC heterostructures, which is assigned to the absorption of BiOCl and BiFeO₃, respectively. SEM results showed that BFO/BOC sample composes of irregular BiFeO₃ nanoparticles and plate-like BiOCl particles. Compared to BiFeO₃, the photocatalytic degradation rate of rhodamine B (Rh. B) and phenol over BFO/BOC increase by 32% and 9%. Electron transfer mechanism analysis reveals that indirect dye photosensitization of BiOCl plays the leading role on the enhanced visible light driven photodegradation of Rh. B.