Carbon nanotubes synthesis over coal ash based catalysts using polypropylene waste via CVD process: Influence of catalyst and reaction temperature.

Autor: Chitriv SP; Department of Chemical Engineering, Visvesvaraya National Institute of Technology, Nagpur, 440010, India., Saini V; Amity School of Engineering and Technology, Amity University, Jaipur, 303002, India., Ratna D; Department of Chemical Engineering, Visvesvaraya National Institute of Technology, Nagpur, 440010, India., P VR; Department of Chemical Engineering, Visvesvaraya National Institute of Technology, Nagpur, 440010, India. Electronic address: vijayakumarrp@che.vnit.ac.in.
Jazyk: angličtina
Zdroj: Journal of environmental management [J Environ Manage] 2024 Aug; Vol. 366, pp. 121881. Date of Electronic Publication: 2024 Jul 16.
DOI: 10.1016/j.jenvman.2024.121881
Abstrakt: Coal ash containing significant amount of SiO 2 and Al 2 O 3 is utilized as a catalyst substrate for carbon nanotubes (CNTs) synthesis. Three different types of catalysts were made by impregnating coal ash with cobalt, iron, and nickel. These catalysts were used to produce CNTs through pyrolysis of waste polypropylene followed by chemical vapor deposition. The influence of catalyst type and reaction temperature (700, 800 and 900 °C) on CNTs yield and its quality was studied in detail. The produced CNTs were characterized by thermogravimetric analysis (TGA), Raman scattering and electron microscopes (FESEM and HRTEM). The TGA results revealed that the Ni catalyst produced CNTs with highest yield (266 %) compared to those synthesized over and Fe (96 %) and Co (95 %). However, the yield of the CNTs from all three metal impregnated coal ash based catalysts was found to have decreased with increase in reaction temperature. The thermal stability of CNTs obtained over different catalysts followed the order of Fe (570 °C) > Ni (550 °C) > Co (530 °C). Further, the Raman analysis demonstrated that the produced CNTs over different catalysts showed increasing degree of graphitization with the rise in reaction temperature. Additionally, the I D /I G ratios indicated that CNTs produced from Fe catalyst showed highest degree of graphitization followed by Co and Ni. FESEM and HRTEM analysis showed that the coal ash based catalysts produced multiwalled CNTs and the diameter of the CNTs was increasing with the rise in catalysis temperature. Therefore, co-utilization of coal ash and waste plastic for production of high value CNTs can be a sustainable approach to waste management while actively contributing in circular economy.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the current work.
(Copyright © 2024 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: