Integration of CeO₂ and Bi₂O₃ nanoparticles with TiO_2-x to fabricate QDs-sized visible-light-triggered materials with efficient performances in the photodegradation of contaminants

The design and synthesis of novel materials with significant performance is the main goal for the researcher working on wastewater treatment methods. Hence, in this work, the visible-light-triggered TiO_2-x/CeO₂/Bi₂O₃ (denoted as T_ov/CeO/BiO) nanocomposites were prepared through a facile hydrothermal route preceded calcination at 400 °C, which presented a QDs size of about 5 nm. The phase, morphology, spectroscopic, textural, and electrochemical characteristics of the samples were investigated by different approaches. The photocatalytic ability was studied against the removal of tetracycline (TC), fuchsine (FS), and malachite green (MG) to exhibit their capability in removing various contaminants. It is confirmed that the T_ov/CeO/BiO nanocomposites exhibit higher photocatalytic ability than pure TiO_2-x and CeO₂/Bi₂O₃ samples. The degradation rate constants of TC, FS, and MG by T_ov/CeO/BiO-4 nanocomposite were 500×10⁻⁴, 205×10⁻⁴, and 324×10⁻⁴ min⁻¹, respectively. The promoted performance is about 16.2, 9.62, and 9.23 folds superior to the TiO_2-x, and 38.1, 16.5, and 29.1 times greater than the CeO₂/Bi₂O₃ photocatalyst for the eliminations of TC, FS, and MG pollutants, respectively. The admirable photocatalytic efficiency of the T_ov/CeO/BiO nanocomposites was associated with improved light harvesting, effective separation of charge carriers, and improved textural features. Additionally, the quenching tests showed that the holes played a prominent role in the degradation of the target pollutant. The reusability of dual S-scheme T_ov/CeO/BiO-4 photocatalyst was studied during four repetitive runs. Ultimately, compared to the untreated solution, it was indicated that the resulting solution after the photocatalytic reaction has a positive impact on the growth of wheat seeds.