Green Synthesis for Antibiotic Photodegradation: Recent Advances and Future Trends

Water contamination by antibiotics has become a critical environmental and public health issue. Among emerging technologies for their removal, heterogeneous photocatalysis has shown remarkable potential. This review provides a systematic analysis of 40 recent studies (2019–2025) that employed green synthesis routes—including sol–gel, hydrothermal, combustion, pyrolysis and co-precipitation methods—for the photocatalytic degradation of antibiotics. The comparison of these techniques revealed that biogenic metal oxides and ferrites synthesized with plant extracts achieved outstanding photocatalytic performance, with degradation efficiencies often exceeding 90–100% for antibiotics such as ciprofloxacin and tetracycline. These results are attributed to the phytochemical composition of the extracts, which are rich in flavonoids, phenols, saponins, tannins, and alkaloids, which act as natural reducing, capping, and stabilizing agents, promoting uniform nucleation, smaller particle sizes, and enhanced crystallinity. The review also highlights the synergistic relationship between biomolecule-mediated reduction and controlled synthesis conditions, which enables the design of sustainable, reusable, and high-efficiency photocatalysts for wastewater treatment and environmental remediation.