Iron‐Oxalate Mediated Photocatalytic Degradation of Catechol by α‐Fe ₂ O ₃ Nanoparticles

ABSTRACT Water contamination by phenolic compounds poses a serious environmental challenge. Among advanced oxidation processes, semiconductor‐mediated photocatalysis using iron oxide nanoparticles offers a promising, sustainable solution. In this study, Fe 2 O 3 nanoparticles were synthesized via a cost‐effective method using ferric nitrate and ethylene glycol. The product was characterized by x‐ray diffraction (XRD), scanning electron microscopy (SEM), energy‐dispersive x‐ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), and diffuse reflectance spectroscopy (DRS). XRD confirmed phase‐pure rhombohedral α‐Fe 2 O 3 , while SEM showed nearly spherical particles with an average diameter of 164 nm. EDX verified a near‐stoichiometric Fe:O atomic ratio, and DRS analysis revealed a direct band gap of 1.9 eV. The photocatalytic activity was evaluated by degrading catechol under UV light in the presence of oxalic acid. Key parameters, including catalyst loading and initial concentrations of catechol and oxalic acid, were systematically optimized. The presence of oxalic acid significantly enhanced degradation via iron‐oxalate complexation, which upon UV exposure generated reactive oxygen species (•, •OOH, and •OH). Under optimized conditions (0.30 g/100 mL catalyst, 1 × 10 −3 M oxalic acid, 1 × 10 −4 M catechol), 79.22% degradation was achieved in 4 h, outperforming commercial Fe 2 O 3 . These findings highlight α‐Fe 2 O 3 nanoparticles as efficient, eco‐friendly photocatalysts for removing organic pollutants from water.