The emergence of nanostructured photocatalysts with high activity offers facile solutions for removing water pollutants. In this study, a novel double Z-scheme TiO2-x/BaBi2O6/Bi2O3 2-x /BaBi 2 O 6 /Bi 2 O 3 nanocomposite with QDs size of about 5.52 nm was prepared by a facile one-pot hydrothermal procedure, and its activity was studied in the photocatalytic degradation of pharmaceutical and dye pollutants. The optimized nanocomposite showed a significant efficiency in the removal of tetracycline, rhodamine B, fuchsine, methylene blue, and chromium (IV), which was 12.4, 7.38, 11.1, 10.2, and 12.1 times higher than pure TiO2-x, 2-x , respectively. The presence of oxygen deficiency in the crystal lattice of TiO2-x/BaBi2O6/Bi2O3 2-x /BaBi 2 O 6 /Bi 2 O 3 nanocomposite played a significant role in the effectual separation of photoexcited charges, increasing reactive active sites, and capturing charge carriers. Besides, providing a short distance for the rapid migration of charges to the surface of the nanocomposite was possible with the quantum size of the catalyst particles. Enforced by the established double Z-scheme heterojunctions, the charge segregation was considerably enhanced along with maintaining their redox capability. Finally, biocompatibility tests showed the harmlessness of the treated solution for agricultural use. (c) 2024 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights are reserved, including those for text and data mining, AI training, and similar technologies.