Ibuprofen vs. methylene blue: Comparative photocatalytic degradation by pristine CeO 2 in water and implications of zeta potential

Abstract Pristine, nanocrystalline CeO 2 with crystallite size 2.18 nm was synthesized in a single step from the reaction of (NH 4 ) 2 [Ce(NO 3 ) 6 ] and NaOH under hydrothermal condition at 180°C for 6 h. Synthesized CeO 2 was characterized by Fourier transforms infrared spectroscopy (FTIR), Powder X‐ray diffraction (PXRD), Field Emission Scanning Electron Microscope (FESEM), and Energy Dispersive X‐ray Spectroscopy (EDX). Also, photocatalytic activity of CeO 2 was determined by band gap measurements using UV‐Vis diffuse reflectance spectroscopy (UV‐Vis DRS) data. Surface area measurement was performed by using a Brunauer‐Emmett‐Teller (BET) surface area analyzer. Furthermore, CeO 2 was evaluated for comparative performance analysis toward catalytic degradation of Ibuprofen (IBU) and Methylene blue (MB) in water under exposure of UV‐C light (15 W) and H 2 O 2 (100 μL). The result highlights the higher efficacy of photocatalyst toward degradation of MB compared to IBU. The degradation of MB in light was observed as 96.9% in 70 min while degradation of IBU remained limited to 63% even after prolonged exposure time of 140 min. The difference in degradation performance of CeO 2 toward IBU and MB in water was investigated. 1.54 times higher degradation of methylene blue in comparison to ibuprofen was achieved over CeO 2 surface, for which the mechanism was elucidated by zeta potential measurement studies.