| Abstract [eng] |
The development of robust and efficient photocatalysts is essential for sustainable wastewater treatment. This study evaluates the photocatalytic degradation of ciprofloxacin (CIP) using three TiO2-coated systems: TiO2 nanotube arrays (TiO2 NTA), Bare-Coated TiO2, and Methanol-Enhanced TiO2, with a focus on coating uniformity, interfacial stability, and reaction pathways. Surface morphology analysis (SEM) revealed that TiO2 NTA exhibited a uniform surface, optimizing active site exposure and photocatalytic efficiency. Methanol-Enhanced TiO2 formed a refined crack pattern, enhancing coating stability and facilitating uniform distribution of TiO2 particles, while Bare-Coated TiO2 showed a highly fractured surface, limiting its catalytic efficiency. X-ray diffraction (XRD) confirmed that the anatase phase was the dominant crystalline structure across all coatings, ensuring photocatalytic activity. High-performance liquid chromatography–mass spectrometry (HPLC-MS) analysis revealed distinct degradation patterns, with TiO2 NTA facilitating rapid fragmentation of CIP into multiple low m/z intermediates, indicating aggressive oxidative breakdown. Methanol-Enhanced TiO2 exhibited a more controlled degradation pathway, with prominent peaks at 316 (+) m/z and 285 (+) m/z, suggesting selective oxidation and gradual mineralization rather than immediate fragmentation. The degradation mechanism of Methanol-Enhanced TiO2 likely favored sustained transformation steps, potentially reducing the accumulation of harmful byproducts. Under ultraviolet (UV)-driven photocatalysis, Methanol-Enhanced TiO2 outperformed Bare-Coated TiO2, achieving accelerated degradation kinetics, while TiO2 NTA maintained high stability but lagged in mineralization efficiency. The introduction of ozone further enhanced degradation, ensuring complete CIP removal across all systems. Methanol-Enhanced TiO2 maintained a degradation efficiency of 88.72% after five reuse cycles, closely matching the 88.75% TiO2 NTA, demonstrating strong reusability and potential for scalable wastewater treatment applications in photocatalytic treatment reactors. These findings underscore the importance of coating methodologies and interfacial properties in optimizing TiO2-based photocatalysts, positioning Methanol-Enhanced TiO2 as a viable and durable alternative to TiO2 NTA for sustainable micropollutant removal. |
