Development and Assessment of Boron, Cerium, and Silver Ternary-Doped Titanium Dioxide Photocatalysts for the UV-A Degradation of Ciprofloxacin Antibiotic

Due to the development of antimicrobial resistance, the continued presence of antibiotic residues in freshwater sources is a growing global concern and hence, it is necessary to degrade the antibiotics present in the polluted waters. In this study, three different boron, cerium, and silver ternary-doped TiO2 photocatalysts with specific compositions were synthesized using the eco-friendly EDTA citrate method. The specific compositions investigated here are B1Ce0.1Ag0.06TiO2, B1Ce1Ag0.06TiO2, and B1Ce1Ag0.1TiO2. From DLS analysis, the particle size of the synthesized catalysts was found to be in the range of 125 – 500 nm. The XRD spectra confirmed the presence of cerium. The DRS analysis showed the bandgap energy of the synthesized catalysts to be in the range of 2.7 – 2.8 eV. ICP-OES analysis was done to check the leaching of the dopants from the catalysts into the solution and the results showed that silver did not leach out while boron (~0.2 ppm) and cerium (~ 0.1 ppm) were present in trace amounts. The catalysts were also evaluated for the degradation of ciprofloxacin antibiotic under UV-A light. At optimized conditions, the best performing photocatalyst namely, B1Ce1Ag0.1TiO2, showed ~54% degradation of the antibiotic in 120 min. This is attributed to the increased amounts of cerium and silver. Although the performance under UV-A irradiation is not encouraging, these results suggest that these catalysts may be more effective under visible or solar light and further work is needed to check the effectiveness under visible light irradiation as well as on larger scales of treatment.