A comparative study on the photodegradation of methyl orange, methylene blue using Fe2O3, Mn2O3, and Fe2O3 – Mn2O3 nanomaterials

Abstract

In this study, photocatalysis was applied to degrade methyl orange (MO) and methylene blue (MB) pollutants using nanoparticles (i.e., Fe₂O₃, Mn₂O₃, Fe₂O₃ – Mn₂O₃). The results were shown that MB was relatively easier to decompose than MO. At the same initial concentration of 10 ppm, all nanomaterials need 120 min to degrade MB from 74.4%-96.5%, while after 180 min, MO is only degraded by 50%-95%. For both pollutants, the mixed nano-oxides of Fe₂O₃-Mn₂O₃ presented a superior treatment efficiency compared to the two single oxides (i.e., Fe₂O₃ and Mn₂O₃). The degradation efficiency was recorded with the order Fe₂O₃-Mn₂O₃> Fe₂O₃> Mn₂O₃. During photodecomposition, formed intermediates due to the incomplete reaction of pollutions and hydroxyl radical were investigated using the ions trap technique.