Facile synthesis of single crystal Fe3O4 sub-microcubes free of any capping agent and their catalytic performance in p-nitrophenol reduction

Currently, controlled synthesis of well-defined micro/nano-scaled catalysts with high performance is one of the most important subjects in the field of catalysis. In this work, single crystal Fe3O4 sub-microcubes with soft-magnetic properties were prepared by a facile and low-cost chemical reduction route, in which no capping agents, such as surfactant, polymer stabilizer or complexant is used. It has been demonstrated that the as-prepared Fe3O4 sub-microcubes exhibited high catalytic activity in the reduction of p-nitrophenol to p-aminophenol with hydrazine hydrate. The activation energy of the reaction is 28.9 kJ mol(-1), which is significantly lower than that of many nanocatalysts recently reported in literature. The recyclable Fe3O4 sub-microcubes can be easily separated from the reaction system by an external magnet and they do not lose their catalytic activity after 6 cycles, thus demonstrating their good reusability.