Porosity effects on TiO 2 -coated ceramic plates for photocatalytic degradation of amoxicillin in an aqueous solution

This study systematically evaluates the effects of substrate porosity (5%, 10%, and 35%) on the photocatalytic degradation of amoxicillin using TiO2 immobilized on ceramic plates. TiO2 was deposited via electron-beam-assisted chemical vapor deposition (CVD). Characterization revealed a significant blue shift in bandgap energy to 3.64–3.90 eV and a 26% improvement in surface hydrophilicity for the 35% porosity sample (C35-Ti). Under UV irradiation, C35-Ti achieved a maximum degradation efficiency of 97.79% (1 mg/L amoxicillin, pH 7, 180 min). Kinetic analysis using the Langmuir–Hinshelwood model showed that the apparent rate constant decreased from 0.01994 to 0.0028 as the initial amoxicillin concentration increased from 1 to 10 mg/L, due to active-site saturation. Optimal activity occurred at pH 7–9, whereas total suspended solids (200 mg/L) reduced efficiency by shading light. Mineralization reached 83.65% as determined by TOC analysis, and the catalyst remained stable after five cycles. These quantitative findings demonstrate the potential of high-porosity TiO2-ceramic systems for effective, reusable removal of antibiotics from wastewater.