Z-scheme Bi2MoO6 nanoplate-decorated flower-like Bi12SiO20 for efficient photocatalytic degradation of organic pollutants

A novel Z-scheme Bi 2 MoO 6 /Bi 12 SiO 20 (MS) heterojunction, with 2D nanoplates of Bi 2 MoO 6 anchored on the surface of flower-shaped Bi 12 SiO 20 particles, was synthesized via simple solvothermal process for the first time. A series of techniques including XRD, XPS, SEM, TEM, BET, UV–vis DRS and Mott–Schottky were used for characterizing the photocatalysts. The MS 0.6 (the heterojunction with a Bi 2 MoO 6 /MS mass ratio of 0.6:1) exhibited optimal photocatalytic activity for degrading RhB, and the reaction rate constant achieved 0.041 min −1 , which was 41 and 4.6 times that of Bi 12 SiO 20 and Bi 2 MoO 6 , respectively. The MS 0.6 also presents outstanding activity for the degradation of BPA (0.014 min −1 ), which was 3.5 and 14 times that of Bi 12 SiO 20 and Bi 2 MoO 6 , respectively. Furthermore, the UV–vis absorption spectrum and TOC test confirmed that the mineralization capacity of Bi 2 MoO 6 was significantly enhanced after coupling with Bi 12 SiO 20 . The enhanced performance was attributed to the improved light absorption and excellent separation efficiency of photo-induced carriers. Trapping and ESR experiments indicated that h + and •O 2 − jointly dominated the degradation of RhB. Therefore, a reliable Z-scheme mechanism was proposed. Additionally, MS 0.6 presented a good stability and durability in four catalytic runs. This study provides an insight for designing highly efficient Z-scheme Bi 12 SiO 20 -based photocatalysts for the practical sewage disposal. Graphical abstract