Abstract:
Advanced oxidation process based on semiconductor photocatalysis is particularly promising for wastewater treatment. Among the various types of photocatalysts, magnetic materials offer the possibility of easy recovery and recyclability post-treatment. Herein a perovskite magnetic material, Aluminium Ferrite (AlFeO3) is synthesized and its properties are studied for photocatalytic application. AlFeO3 has a direct bandgap of 2.0 eV which is suitable for visible-light photoactivity.

The photocatalytic efficiency of AlFeO3 is tested using degradation of textile dye pollutants such as Rhodamine B (RhB) and Methyl Orange (MO). The reaction is carried out in the visible-light photocatalytic reactor using static and air bubbling conditions instead of the traditional magnetic stirring method. In the static condition, AlFeO3 efficiently degrades 99% of RhB in 180 mins and 94% of MO in 270 mins. The degradation rate is increased 1.5 times in the air bubbling method when compared to the static approach. AlFeO3 also shows photocatalytic activity under UV light and degrades RhB at a rate constant of 8.8×10-3 min-1. The catalyst is retrieved from the treated water using a bar magnet and reused over 5 subsequent cycles. The toxicity of the AlFeO3 is also tested for the first time using L929 fibroblast cells. The material is found to be non-toxic with a cell viability of more than 90%. Hence, AlFeO3 proves to be a potential non-toxic UV-Visible photocatalyst.

Going forward, nanocomposites of the AlFeO3 and Indium doped AlFeO3 will be tested for the degradation of representative textile and pharmaceutical pollutants.