Enhanced Carbon Nanotubes Growth Using Nickel/Ferrocene-Hybridized Catalyst

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Achieving tall, crystalline carbon nanotubes (CNTs) is crucial for advanced applications.
• Higher growth temperatures improve CNT crystallinity but can degrade catalysts in chemical vapor deposition (CVD).
• Catalyst particle degradation limits CNT growth rate at elevated temperatures.

Purpose of the Study:

• To investigate the effect of a nickel/ferrocene-hybridized catalyst on CNT growth.
• To compare the performance of hybridized catalyst against a sole ferrocene catalyst.
• To optimize CNT growth conditions for improved height and crystallinity.

Main Methods:

• Carbon nanotubes (CNTs) were grown using volatile catalyst source (ferrocene/xylene) CVD.
• Substrates included bare silicon (Si) and nickel (Ni) catalyst-deposited Si (5-30 nm).
• Growth temperatures ranged from 790 to 880 °C, with characterization via electron microscopy and Raman spectroscopy.

Main Results:

• CNTs grown on bare Si showed reduced height above 860 °C.
• CNTs on Ni-catalyzed substrates exhibited continuous height increase from 790 to 880 °C.
• The Ni/ferrocene catalyst yielded taller CNTs with enhanced structural crystallinity.

Conclusions:

• Nickel hybridization significantly improves catalyst activity and CNT growth.
• This method enables the growth of taller, more crystalline CNTs at higher temperatures.
• The findings offer a pathway to overcome limitations in CNT production for various applications.