Green synthesis of Fe3O4 nanoparticles with controlled morphologies using urease and their application in dye adsorption.

This paper describes a simple and environmentally friendly method for the preparation of highly stable dispersions of Fe3O4 nanoparticles with controlled morphologies, in the same synthesis system for the first time. During the process, the Fe3O4 nanoparticles are formed using urease as a multifunctional reagent, including catalyst, template and dispersant, due to its enzymatic activity and special enzymatic steric structure. A possible formation mechanism for these Fe3O4 nanoparticles, which have various morphologies including nanospheres, nanosheets and nanorods, is proposed. The as-prepared nanoparticles show a larger specific surface area and a stronger magnetism, which enhances their dye adsorption capacity and increases their potential for application in wastewater treatment.