Synthesis and Investigation of Flower-Like and Microrod-Like Titania Structures for Antibacterial and Photocatalytic Wastewater Treatment

Titanium dioxide (TiO2) nanostructures have garnered significant attention for their exceptional photocatalytic and antibacterial properties in wastewater treatment applications. In this study, a simple, surfactant-free hydrothermal method was developed to synthesize flower-like and microrod-like TiO2 architectures directly on fluorine-doped tin oxide (FTO) substrates, aiming to enhance photocatalytic efficiency and antimicrobial performance. X-ray diffraction (XRD) confirmed the formation of the anatase phase with distinct TiO2 and SnO2 crystallographic planes, indicating high phase purity and crystallinity. Field emission scanning electron microscopy (FESEM) revealed uniformly distributed microrods (diameter 40–60 nm, length 1–2 μm) forming three-dimensional flower-like assemblies, offering increased surface area and improved charge-transport pathways. Fourier transform infrared (FTIR) spectra identified Ti–O–Ti and Ti–OH functional groups, crucial for hydroxyl radical formation and interfacial charge transfer. The antibacterial activity, evaluated using the agar well diffusion method against Escherichia coli, Staphylococcus epidermidis, Proteus vulgaris, and methicillin-resistant Staphylococcus aureus (MRSA), exhibited inhibition zones ranging from 12 to 18.5 mm, with MRSA showing the highest susceptibility. The antibacterial mechanism is attributed to the combined effects of reactive oxygen species (ROS) generation and surface-induced membrane disruption. Photoluminescence (PL) analysis displayed a strong UV emission at 330 nm, confirming suppressed electron–hole recombination and enhanced charge separation efficiency. The hydrophilic nature of the TiO2 surface (contact angle ≈ 35°) facilitates efficient pollutant adsorption and self-cleaning behavior. Overall, the study demonstrates that the hierarchical, morphology-controlled TiO2 microrod structures synthesized via this economical and eco-friendly hydrothermal route exhibit superior photocatalytic degradation (∼92% of methylene blue within 120 min) and potent antibacterial efficacy. Despite limited visible-light activity, the findings open avenues for band-gap engineering and hybridization with graphene, Ag, Cu, or ZnO to extend solar utilization. The developed TiO2 films hold strong potential as scalable, reusable, and sustainable photocatalysts for integrated wastewater purification and microbial disinfection technologies.