In this work, novel Bi2WO6-ZnBi2O4 p-n heterojunction was successfully synthesized through combination of sonochemical and hydrothermal procedures. The results revealed that the sonochemically prepared nanocomposites had spherical shape with amorphous structure which became crystalline particles with flak-like morphology after hydrothermal treatment. Bi2WO6-ZnBi2O4 nanocomposite with 20 wt% ZnBi2O4 content demonstrated the highest photocatalytic performance compared to the pure Bi2WO6 and ZnBi2O4 samples toward the degradation of Malachite Green (MG). This finding is associated with the efficient separation of photo-generated electron/hole pairs due to the formation of interfacial charge transfer between Bi2WO6 and ZnBi2O4. However, further ZnBi2O4 loading had no significant effect on the enhancement of photocatalytic activity of nanocomposite samples owing to the shielding effect …