Chemical synthesis of Fe3O4–graphene oxide nanohybrids as building blocks for magnetic and conductive membranes

Abstract

Abstract We have developed a facile and scalable method for synthesising superparamagnetic Fe 3 O 4 nanocrystals (NCs) anchored on graphene oxide (GO) sheets by a co-precipitation reaction. As-synthesized Fe 3 O 4 –GO nanohybrids (NHs) were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, atomic force microscopy, field-emission scanning electron microscopy, transmission electron microscopy, and vibrating sample magnetometer. Fe 3 O 4 NCs with a narrow size distribution (4.5 ± 0.6 nm) were uniformly decorated over GO surface at high density. The GO sheets act as two-dimensional substrates and surfactants for the growth and adhesion of Fe 3 O 4 NCs. Structural changes induced in the GO due to Fe 3 O 4 decoration were clearly observed using Raman spectroscopy. The magnetic properties of Fe 3 O 4 –GO NHs could be tuned by varying Fe 3 O 4 content and a saturation magnetization as high as 39.2 emu g −1 was achieved. Fe 3 O 4 –GO NHs in their colloidal suspension were used as building blocks to fabricate magnetic and electrically conductive membranes by a vacuum-assisted assembly process.