Rotating Photo-Disc Reactor (RPR) Used in the Photo-Degradation of Pyridine Using Zinc Oxide as a Catalyst Composited with Aluminum Nanoparticles and Irradiated with Natural Light

Pyridine was degraded in a rotating photo-disc reactor (RPR) using zinc oxide (ZnO) doped with aluminum nanoparticles (ZnO-Al) as a catalyst and natural light lamps. The reactor disks made of clay had a surface area of 329.7209 m2. The reactor was operated as a semi-batch system, where it handled a volume of 14.8 L and had a hydraulic residence time (HRT) of 72 h at 54 rpm with a constant flow rate. The results indicate an average degradation of 50.6% after an HRT of 72 h, with a maximum degradation of 62%. The characterization results confirm the effectiveness of the doping process, showing an aluminum concentration of 4.11% by mass in the catalyst, as determined by X-ray techniques. Overall, the doping process proved effective for the zinc oxide catalyst, as evidenced by a reduction in the catalyst bandgap from 3.25 eV for undoped ZnO to 3.08 eV for the doped version, making it sufficiently active under artificial visible light.