Preparation of the carbon nanotubes by catalytic pyrolysis of waste plastic and application for electromagnetic shielding

This study reports the synthesis of carbon nanotubes (CNTs) via the catalytic pyrolysis of waste plastics using Fe/MgO and Ni/MgO catalysts for electromagnetic interference (EMI) shielding. The growth mechanism proceeds through the reduction of metal species into nanoparticles, followed by the catalytic decomposition of plastic-derived C ₂ H ₄ and the subsequent precipitation of graphitic carbon from unstable carbide intermediates (e.g., Fe ₃ C). Results demonstrate that Fe-based CNTs with 50 wt% loading achieve a shielding effectiveness of 26.3 dB in the 8-18 GHz range, exceeding the commercial standard (20 dB) due to their dense network structure and high electrical conductivity. These findings underscore the immense potential of upcycling waste plastics into high-performance EMI shielding materials and clean energy, offering a sustainable route for highly efficient resource valorization.