Alternative Metallocenes in Floating Catalyst-CVD: Synthesis of Novel Carbon Nanostructures

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Floating catalyst chemical vapour deposition (FC-CVD) is a primary method for synthesizing carbon nanotubes (CNTs).
• Ferrocene is the conventional catalyst, but its limitations necessitate exploring alternatives.
• Understanding catalyst influence is key to controlling nanocarbon formation.

Purpose of the Study:

• To investigate the impact of nonferrous metallocenes on carbon nanostructure formation.
• To explore alternative catalysts for FC-CVD beyond ferrocene.
• To characterize the resulting nanostructures and their morphologies.

Main Methods:

• Six metallocenes (ferrocene, cobaltocene, ruthenocene, vanadocene, manganocene, magnesocene) were tested.
• Comparable FC-CVD conditions were maintained for all catalysts.
• Materials were characterized using SEM, Raman spectroscopy, and EDS.

Main Results:

• Ferrocene yielded highly crystalline, vertically aligned CNT carpets.
• Cobaltocene and magnesocene produced less aligned, more defective CNTs.
• Ruthenocene and vanadocene resulted in disordered graphitic carbon.
• Manganocene catalyzed unique dendritic structures with functionalized surfaces.

Conclusions:

• Nonferrous metallocenes can direct the growth of unconventional carbon nanostructures.
• Catalyst selection offers a route to tailor nanocarbon morphology.
• Findings open possibilities for applications requiring specific nanocarbon properties.