Nano-Fe 3 O 4 /O 2 : Green, Magnetic and Reusable Catalytic ... Mohammad Ali Zolfigola,*, Vahid Khakyzadeha, Ahmad Reza Moosavi-Zareb, Abdolkarim Zarec, Parastoo Arghavani-Hadia, Zahra Mohammadia and Mohammad Hassan Beyzavid ... ABSTRACT Magnetic nano-Fe3O4 was applied in the presence of atmospheric air as a green, efficient, heterogeneous and reusable catalytic system for the synthesis of benzimidazoles via the reactions of o- ...