Laser-enhanced and UV-driven photocatalysis for the degradation of methylene blue using CeO₂ nanostructures; A comparative study

Abstract Water pollution caused by organic dyes, particularly methylene blue (MB), poses a significant environmental challenge. This study investigates the novel application of laser-enhanced photodegradation of MB using cerium oxide (CeO 2 ) nanostructures (NSs) as a semiconductor photocatalyst. CeO 2 NSs were synthesized via a precipitation method employing Ce(NO 3 ) 3 ·6H 2 O and NaOH at room temperature, followed by calcination at 600°C for 2 hours. The structure of the CeO 2 NSs was analysed using XRD, FTIR, EDX, SEM and FESEM. To our knowledge, for the first time, photocatalytic activity of CeO 2 NSs under laser light irradiation was studied and contrasted with the UV light degradation. These results showed that laser induced photodegradation (12.11% in 1 hour) was much more effective than UV light degradation (4.89% in 1 hour). These improvements are due to the more better Ce 3+ /Ce 4+ redox couple which helps in the production of reactive oxygen species that in turn increases the degradation of MB under laser. This research, therefore, aims at proposing an improved efficient method of removal of organic contaminants from the wastewater with an emphasis on the dye-contaminated industrial effluents. More studies should be conducted to enhance these strategies use in large scale in wastewater treatment.