Reduced Graphene Oxide Obtained by Hummers and Marcano-Tour Methods: Comparison of Electrical Properties

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Graphene oxide (GO) and reduced graphene oxide (rGO) are crucial materials in various applications.
• Different synthesis methods yield GO/rGO with distinct structural and electronic properties.
• Understanding these properties is key to optimizing their performance.

Purpose of the Study:

• To compare structural, morphological, and electrical properties of GO synthesized by Hummers and Marcano-Tour methods.
• To characterize rGO obtained via hydrothermal hydrazine-assisted reduction.
• To elucidate charge transport mechanisms in these materials.

Main Methods:

• Synthesis of graphene oxide using Hummers and Marcano-Tour approaches.
• Reduction of graphene oxide via hydrothermal hydrazine-assisted route.
• Characterization using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), low-temperature nitrogen absorption, and impedance spectroscopy.

Main Results:

• rGO from Hummers route: plate-like agglomerates, short interlayer distances, smaller diameter, larger thickness particles.
• rGO from Marcano-Tour method: mesoporous solid, randomly aggregated linear carbon fragments.
• Proton conductivity suggested as the dominant charge transport mechanism for both GO samples.
• Charge migration within graphene fragments and charge hopping between fragments observed in rGO.

Conclusions:

• The Hummers and Marcano-Tour synthesis routes produce rGO with significantly different morphologies.
• Morphology strongly influences the charge transport properties of reduced graphene oxide.
• Proton conductivity plays a vital role in the electrical behavior of these graphene-based materials.