Ni3Fe@N-doped carbon nanotubes 3D network induced by nanoconfined symmetry breaking for high-performance microwave absorption, corrosion protection, and pollutant purification

It remains challenging to develop multifunctional electromagnetic wave (EMW) absorbers with anti-corrosion and pollutant purification capabilities suitable for extremely harsh ocean environments. This study exploits symmetry breaking to construct a three-dimensional (3D) network of bamboo-like N-doped carbon nanotubes (NCNT) encapsulated with magnetic Ni3Fe nanocatalysts via facile coordination and catalytic chemical vapor deposition process. The resulting Ni3Fe@NCNT composite demonstrates outstanding EMW absorption performance, anti-corrosion behavior, and adsorption purification function. Its excellent EMW absorption performance, including a minimum reflection loss of −57.3 dB and a maximum effective absorption bandwidth of 6.0 GHz, is achieved by magnetic-dielectric match, inert space platform, and porosity architecture. The Ni3Fe@NCNT composite also shows corrosion resistance and self-cleaning function simultaneously because of the physical shield provided by the intrinsically impermeable, inert NCNT shells and their considerable chemically active site and high porosity. For the first time, the EMW absorber is endowed with cooperative multi-functionalities. Our findings may pave the way to manufacture versatile EMW materials for applications in complicated environments.