Rapid synthesis of carbon nanotubes from Prosopis Juliflora biochar using microwave irradiation

Abstract

Biochar, prepared from Prosopis Juliflora (PJ) through slow pyrolysis, was used as biological precursor material for Carbon nanotubes (CNTs) synthesis. Microwave assisted heating was used to synthesize CNTs from a mixture of PJ wood biochar and ferrocene. The experiment performed at operating condition 150 °C temperature and 3-minute residence time. Biochar derived CNTs were investigated by Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray diffraction and Raman Spectroscopy. Among the biochar produced at different pyrolysis temperature (300–600 °C), biochar produced at higher temperature (600 °C) produced higher concentration of CNTs. CNTs range in size from 10 to 60 nm in diameter and 0.208 μm to 3 μm in length. TEM images also showed the formation of nano-biochar in all biochars. CNTs produced using high-temperature biochar as precursor had relatively higher degree of wall graphitization, superior quality, crystallinity, and fewer flaws (i.e., CNT600 > CNT500 > CNT400 > CNT300) which was confirmed by Principal Component Analysis. The findings show that the temperature at which PJ wood is pyrolyzed has an impact on the physicochemical properties of CNTs. Results also show that a good quality and quantity of CNTs can be synthesized using PJ wood derived biochar as a precursor material.