In-situ construction of Bi2SiO5/BiOBr heterojunction with significantly improved photocatalytic activity under visible light

To further improve the light response range and photocatalytic activity of Bi2SiO5, the Bi2SiO5/BiOBr type-Il heterojunction photocatalysts were constructed by in-situ partial ion exchange strategy using Bi2SiO5 as precursor. The crystal phases, morphologies, chemical compositions, optical properties and textural structures of as-synthesized Bi2SiO5/BiOBr photocatalysts were characterized by the corresponding analytical techniques. The photocatalytic activities of samples were evaluated by degrading Rhodamine B (RhB) solution under visible light irradiation. The results showed that the Bi2SiO5/BiOBr heterojunction photocatalysts significantly improved the photocatalytic performances, which would be ascribed to the extended light response, enhanced adsorption capacity, matched energy band structures and intimate interface contact. Construction of Bi2SiO5/BiOBr heterojunction facilitated the separation and transfer of photoexcited charge carriers, which were verified by the electrochemical impedance spectroscopy (EIS), transient photocurrent response and steady photoluminescence spectroscopy (PL) measurements. This work would offer a new insight into the design and preparation of Bi2SiO5-based heterojunction photocatalysts for the removal of organic contaminant. (C) 2019 Elsevier B.V. All rights reserved.