Synthesis of α-Fe2O3 nanorod/graphene oxide composites and their tribological properties

The composites of graphene oxide (GO) nanosheets fabricated by alpha-Fe2O3 nanorods were prepared through a facile hydrolysis route. As-synthesized alpha-Fe2O3 nanorods incorporated into GO nanosheets in the composites were observed with diameters of 3-5 nm and lengths of 15-30 nm. The formation mechanism of anchoring alpha-Fe2O3 nanorods onto GO nanosheets was proposed as the intercalation and adsorption of iron ions onto the surface of GO nanosheets, followed by the nucleation and growth of alpha-Fe2O3 nanorods. Tribological properties of alpha-Fe2O3 nanorod/GO composites as lubricating oil additive were investigated by employing a ball-plate tribotester. It is shown that anti-wear and reduced frictional abilities were improved by the addition of alpha-Fe2O3 nanorod/GO composites into the base oil. The oil with alpha-Fe2O3 nanorod/GO composites showed better tribological properties than those in the oil with GO nanosheets. Good friction and wear properties of alpha-Fe2O3 nanorod/GO composites can be explained by the combination of rolling effects between the rubbing surface and formed thin physical tribofilms on the substrate.