Turbostratic Carbon/Graphene Prepared via the Dry Ice in Flames Method and Its Purification Using Different Routes: A...

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• The dry ice method offers a low-cost, scalable route for synthesizing turbostratic carbon/graphene.
• A key limitation is the presence of magnesium oxide impurities in the synthesized material.

Purpose of the Study:

• To investigate efficient methods for removing magnesium oxide from turbostratic carbon/graphene.
• To optimize purification processes for this synthesis method.

Main Methods:

• Tested three acid chemical leaching processes: hydrochloric acid, aqua regia, and piranha solution.
• Incorporated mechanical milling, particularly high-energy mechanical milling, to enhance oxide removal.
• Quantified residual magnesium oxide using weight percentage (wt.%).

Main Results:

• Aqua regia combined with mechanical milling achieved the lowest residual magnesium oxide content (0.9 wt.%).
• Other methods resulted in significantly higher residues (2.8-29.6 wt.%).
• High-energy mechanical milling facilitated magnesium oxide exfoliation and acid dissolution.

Conclusions:

• Optimized purification involves aqua regia leaching and mechanical milling for turbostratic carbon/graphene.
• This treatment yields a high-purity material with a surface area of 504.8 m²g⁻¹, suitable for diverse applications.
• The dry ice method, with optimized purification, presents a viable route for producing advanced carbon materials.