▎ 摘　　要

This work investigates the role of hydroxyl and epoxy bridges in room-temperature ferromagnetism (FM) of pyrolytic graphene oxide nanoplatelets (GOs). Graphene oxide nanoplatelets were synthesized from bamboo pyroligneous acid (BPA), varying oxide coverage (OC) from 5.3% to 13.0%. The amount of hydroxyl and epoxy functional groups in all the GO samples were estimated from results analysis of X-ray photoelectron spectroscopy (XPS). An FM signal was identified, measured at room temperature, which scaled with oxide coverage. Decreased oxide coverage results in enhanced FM. A combination of results from high-resolution transmission electron microscopy (HR-TEM), XPS, energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), electron energy loss spectroscopy (EELS), Fourier transform infrared (FTIR), Raman, and electrical characterization allowed constructing an atomic model for each graphene oxide (GO) structure. First-principles calculations of the atomic model suggest that FM is induced by the adsorption of -OH and -O- atoms on graphene nanoplatelets; therefore, their magnetism is a response to the number of uncompensated spins due to topographic defects. These results suggest future possibilities of the magnetism approach of pyrolytic GO in spintronics of advanced sensors and devices.