Photocatalytic degradation of antibiotics in water via TiO2-x: Research needs for technological advancements

• Exploring non-traditional light sources expands application possibilities. • Upconversion materials may improve TiO 2-x activation under low-energy light. • Challenges remain in scaling up to real-world water treatment applications. • Research needed on catalyst performance in complex water matrices. • Innovative recovery methods and long-term stability are key research priorities. Antibiotic contamination in water systems poses significant risks to public health and ecosystems by contributing to antibiotic-resistant bacteria proliferation. Conventional water treatment methods often fail to remove these pollutants effectively, necessitating more efficient technologies. Recent advancements in TiO 2-x photocatalysts for antibiotic degradation in water have shown promise. Strategies to optimize TiO 2-x photocatalysts include doping, heterojunction formation, and hierarchical nanostructure design. Studies demonstrate significant improvements in antibiotic degradation under both ultraviolet and visible light, with some achieving complete mineralization. However, challenges remain in scaling up to real-world applications, including maintaining efficiency in complex water matrices, developing efficient recovery methods, ensuring long-term stability, and addressing environmental risks of nanoparticle release. Key research directions for technological advancement include rigorous testing under actual solar conditions and exploring nontraditional light sources like LEDs for 24-h operation. Developing multifunctional photocatalysts capable of simultaneous antibiotic degradation and bacterial inactivation is crucial. Increasing selectivity towards specific antibiotics through molecular imprinting techniques and integrating TiO 2-x with other advanced oxidation processes and biological treatments for synergistic effects are important areas of focus. Designing scalable synthesis methods and innovative reactor designs for large-scale implementation is essential. Establishing standardized evaluation metrics for meaningful performance comparisons and conducting comprehensive environmental impact assessments of nanoparticle release are necessary. Leveraging artificial intelligence for rapid material optimization and predictive modeling of photocatalytic processes shows great potential. Synthesizing current knowledge and highlighting these research priorities, this review aims to guide the development of effective and sustainable water treatment solutions for antibiotic contamination.