Synthesis and characterization of anisotropically expanded graphite oxide compounds derived from spherical graphite

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Graphite oxide (GO) is a versatile material with potential applications in energy storage.
• Controlling the interlayer distance and morphology of GO is crucial for optimizing its properties.
• Mesocarbon microbeads (MCMB) serve as a precursor for synthesizing tailored GO materials.

Purpose of the Study:

• To synthesize anisotropically expanded graphite oxide (GO) compounds with controlled interlayer distances.
• To investigate the effect of various quaternary ammonium cations on GO interlayer spacing and morphology.
• To evaluate the electrochemical performance of the synthesized expanded GO compounds as electrode materials.

Main Methods:

• Intercalation of quaternary ammonium cations (tetrabutylammonium, tetraoctylammonium, dioctadecyldimethyl ammonium) into GO derived from MCMB.
• Characterization of interlayer distances using techniques such as X-ray diffraction (results not explicitly stated but implied by distance measurements).
• Morphological analysis of the synthesized GO compounds (results not explicitly stated but implied by observations).

Main Results:

• Successfully synthesized anisotropically expanded GO with varying interlayer distances (1.1 nm for TBA-GO, 1.9 nm for TOA-GO, 2.9 nm for DDA-GO).
• Observed significant morphology changes in TOA-GO and DDA-GO, indicating cation-dependent structural modifications.
• Expanded GO compounds demonstrated lower water content and improved thermal stability compared to pristine GO.
• All synthesized expanded GO compounds exhibited typical capacitive behavior when tested as electrode materials for electrochemical capacitors.

Conclusions:

• The interlayer distance and morphology of GO can be effectively tailored by selecting appropriate intercalated quaternary ammonium cations.
• The expanded GO compounds possess enhanced thermal stability and reduced water content, making them suitable for demanding applications.
• The synthesized expanded GO materials show promise as efficient electrode materials for electrochemical capacitors, delivering typical capacitive performance.