Abstract
In this work, carbon nanotubes (CNTs) were synthesized by catalytic pyrolysis from waste polyethylene in Ar using an in-situ catalyst derived from ferric nitrate and nickel nitrate precursors. The influence factors (such as temperature, catalyst content and Fe/Ni molar ratio) on the formation of CNTs were investigated. The results showed that with the temperature increasing from 773 to 1073 K, the carbon yield gradually increased whereas the aspect (length-diameter) ratio of CNTs initially increased and then decreased. The optimal growth temperature of CNTs was 973 K. With increasing the Fe/Ni molar ratio in an FeNi bimetallic catalyst, the yield of CNTs gradually increased, whereas their aspect ratio first increased and then decreased. The optimal usage of the catalyst precursor (Fe/Ni molar ratio was 5:5) was 0.50 wt% with respect to the mass of polyethylene. In this case, the yield of CNTs reached as high as 20 wt%, and their diameter and length were respectively 20–30 nm, and a few tens of micrometers. The simple low-cost method developed in this work could be used to address the environmental concerns about plastic waste, and synthesize high value-added CNTs for a range of future applications.
Highlights
As a lightweight, waterproof, and corrosion resistant material, plastic is widely used in almost every aspect of human society, contributing considerably to the economic growth and social sustainability [1]
Where, C is residual carbon rate, m1 is the weight of composite powder, m2 is the total weight of composite powder and alumina crucibles before pyrolysis, m3 is the total weight of composite powder and alumina crucibles after pyrolysis, m2–m3 is the weight loss of waste polyethylene precursor before and after pyrolysis, and m4 is the weight of adding Fe/Ni catalyst theoretically
As the pyrolysis temperature increased to 873 K, the peak height of graphitic carbon increased
Summary
Waterproof, and corrosion resistant material, plastic is widely used in almost every aspect of human society, contributing considerably to the economic growth and social sustainability [1]. Exploring a simple, low-cost and sustainable way to recycle plastic waste to form high value-added products, though very challenging, is of technical importance Carbon materials such as graphite, graphene and carbon nanotubes (CNTs) have attracted a lot of attention [7,8,9,10,11,12,13,14,15,16]. CNTs can be synthesized by arc discharge [20], flame synthesis [21], microwave-assisted synthesis [22], chemical vapor deposition [23], and catalytic pyrolysis [24], among which, the last one has proved promising With this method, polyolefin, which has a high carbon content, is usually used as the carbon source because the plastic waste is mostly hydrocarbon polymers [25,26,27,28,29,30]. The influence parameters of pyrolysis temperature, catalyst content and Fe/Ni molar ratio on the formation of CNTs were investigated
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
