Green synthesis of the Fe3O4@polythiophen-Ag magnetic nanocatalyst using grapefruit peel extract: Application of the catalyst for reduction of organic dyes in water

In this research Fe3O4@polythiophen-Ag magnetic nanocatalyst was synthesized. First Fe3O4 nanoparticles were prepared in the solution and the branched polythiophene was coated on the magnetic particles. This polymer provides enough surface for precipitation of the silver nanocatalyst produced by grapefruit peel extract reduction of AgNO3. The synthesized catalyst was characterized by XRD, FTIR, SEM, FESEM, EDX, TEM, TGA and VSM. Finally, it was used to degrade azo dyes (methyl orange (MO) and methylene blue (MB)) in order to evaluate its catalytic performance. Ratio of the rate constants of the catalytic and non-catalytic reactions was in order of 105 and 104 for reduction reaction of MB and MO respectively. Reaction rate in the presence of catalyst was very high and just 1 min was enough to degrade the MB and MO colorant reagents. The prepared catalyst is able to take part many times in the reaction. It was recovered by a magnet after each experiment and reused 8 times without considerable loss of the activity.