One-pot hydrothermal synthesis of CuBi2O4/BiOCl p–n heterojunction with enhanced photocatalytic performance for the degradation of tetracycline hydrochloride under visible light irradiation

Abstract

We synthesized a CuBi₂O₄/BiOCl p–n heterojunction photocatalyst by a convenient one-pot hydrothermal method. And the morphology, crystal phase, element composition and optical properties of as-synthesized CuBi₂O₄/BiOCl were analyzed utilizing SEM, EDS, TEM, XRD, XPS, UV-visible DRS, PL and EIS techniques. Under visible light, the CuBi₂O₄/BiOCl p–n heterojunction exhibits excellent photocatalytic activity for the degradation of tetracycline hydrochloride, and when the CuBi₂O₄ content in the heterojunction is 20 wt%, the photocatalytic activity of the CuBi₂O₄/BiOCl heterojunction is the highest, which is 58.2 times and 4.1 times that of pristine CuBi₂O₄ and BiOCl, respectively. The photocatalytic activity of the heterojunction increased with the enhancement of visible light absorption and the effective separation of photogenerated electron–hole pairs which is promoted by the built-in electric field. In addition, a radical trapping study showed that h⁺ and ˙O₂⁻ radicals were the main active species in the photocatalytic process. On this basis, the possible photocatalytic mechanism was discussed.