Decoration of Carbon Dots on Oxygen-Vacancy-Enriched S-Scheme TiO2 Quantum Dots/TiO2 Oxygen Vacancies Photocatalysts: Impressive Quantum-Dot-Sized Photocatalysts for Remediation of Antibiotics, Bacteria, and Dyes

Today, cleaning the environment using photocatalytic technology is one of the main research activities. In this study, carbon dots (C-dots) were anchored on oxygen-vacancy-enriched TiO2 quantum dots (QDs)/TiO2 oxygen vacancies (OVs) using a facile procedure. The resultant ternary TiO2 QDs/TiO2 OVs/C-dots photocatalysts with a quantum dot size of almost 4.55 nm were used for detoxification of aqueous solutions containing four antibiotics and three organic dyes as well as inactivation of two pathogenic bacteria, including Escherichia coli and Staphylococcus aureus, upon visible light. The degradation constant of tetracycline over the optimized TiO2 QDs/TiO2 OVs/C-dots nanocomposite reached 714 × 10–4 min–1, which was 17.3, 12.1, and 2.92 times higher than TiO2 QDs, TiO2 OVs, and TQDs/TOVs (1:1) materials, respectively. Effective separation of electron–hole pairs between TiO2 QDs and TiO2 OVs counterparts through decorated C-dots by an established S-scheme system was the main reason for boosted photocatalytic activity. With regard to the facile growth of wheat and lentil seeds in the treated solutions, it is hoped that the TiO2 QDs/TiO2 OVs/C-dots nanocomposite with significant stability could be used to clean up wastewaters.