The synergistic effects study between metal oxides and graphene on far-infrared emission performance

Abstract

Materials with high far-infrared (FIR) emissivity are quiet promising in modern medical care field, owing to its accelerating effects to blood circulation and metabolism. In this work, we synthesized two serials composites: MnO2/graphene nanoplate (GNPs) and Fe2O3/GNPs via in situ hydrothermal process. Positive synergistic effects on FIR emission were shown between either MnO2 or Fe2O3 and GNPs. In particular, MnO2/GNPs (2%) showed a super high FIR emissivity of 0.981 compared with pristine MnO2 (0.940) and GNPs (0.878) in the wavelength of 8–14 µm. The FIR emissivity of Fe2O3/GNPs (1%) was up to 0.953 that was much higher than those of pristine Fe2O3 (0.877) and GNPs as well. Benefiting from the characteristics of graphene such as large specific surface, lightweight and thin-layer, MnO2 and Fe2O3 nanocrystals grew on graphene surface and formed different morphologies. A coralloid-like morphology was formed to MnO2/GNPs (2%), suggesting a highly porous surface that meant more unstable atoms or molecules were exposed. The morphologies of metal oxide/GNPs were thought to relate with the good synergistic effects between GNPs and metal oxides. Therefore, this work provides that metal oxides/graphene composites have promising application for high FIR emission materials.