Nickel oxide-sprinkled in-situ grown hierarchal graphitic jungle anchored feathery aluminum foam: A novel material for remarkable electromagnetic waves absorption

Abstract

Electromagnetic waves (EMW) absorbing materials with low density are in high demand because the miniaturization of devices requires high electromagnetic shielding. Metal foams (especially open-cell Aluminum foam, OCAF), due to their lightweight and reasonable mechanical properties, are considered encouraging materials for the aforementioned applications. OCAF counters the high-density issue, and also makes it compatible with impedance matching. Here nickel oxide (NiO)- sprinkled in-situ grown hierarchal graphitic carbon nanofiber anchored feathery OCAF (Al–NiO–CNF OCAF) is synthesized through a novel template method. The materials are explored intensively using different physico-electro-chemical, mechanical, and magnetic techniques. The EMW absorption capacity gets remarkably increased (four times) with the presence of NiO and hierarchal graphitic jungle. The total electromagnetic interference shielding is found to be ∼84 dB at 10.4 GHz, out of which 82 dB is the absorption component (>98%). The prepared Al–NiO–CNF OCAF approves the new pathway for the use of metal-based lightweight materials for high EMW absorption applications. The Al–NiO–CNF OCAF has shown better mechanical and environmental stability. This study demonstrates a simple alternative material for promising electromagnetic interference shielding and EM absorption capabilities in various orientations.