Laser-enhanced CeO2 nanorods for efficient photocatalytic degradation of naproxen

The growing presence of pharmaceutical pollutants such as naproxen in aquatic systems poses major challenges to conventional water treatment. Cerium oxide nanorods (CeO2 NRs), known for their cost-effectiveness, high redox potential, and environmental compatibility, offer a promising solution for sustainable remediation. In this study, cerium dioxide NRs were synthesized via a hydrothermal method at controlled temperatures ranging from 363 to 423 K. X-ray diffraction confirmed the formation of a face-centered cubic fluorite phase, with crystallite sizes decreasing from 21.514 to 6.237 nm as synthesis temperature increased. Field-emission scanning electron microscopy revealed a temperature-driven morphological transformation from elongated to cuboidal rods, with length reduction from 206 to 94.9 nm. Fourier transform infrared spectroscopy identified characteristic Ce–O and Ce–O–Ce vibrations, with higher temperatures yielding enhanced crystallinity and reduced surface adsorbates, improving photocatalytic performance. Ultraviolet–visible spectroscopy showed a bandgap reduction from 3.74 to 3.21 eV. The optimally synthesized nanorods achieved 59% naproxen removal under xenon lamp irradiation (λ > 300 nm, 300 W) and 71.01% degradation under blue laser light (λ = 450 nm, 100 mW) within 150 min. These findings demonstrate a practical and scalable approach for rapid pharmaceutical pollutant removal and sustainable water treatment.