Hydroxylated multi-walled carbon nanotube-induced in-situ growth of zinc oxide flower structures: Preparation and performance of high-performance electromagnetic wave absorbing nanocomposites

With the rapid advancement of the information age, electromagnetic waves have brought convenience to people while also posing numerous problems and challenges. Developing absorptive materials that combine strong absorption, wide bandwidth, low density, and high stability has become a core research direction in the field of materials science. Using the hydrothermal method, a flower-like zinc oxide/multi-walled carbon nanotube nanocomposite was synthesized with hydroxylated multi-walled carbon nanotubes as the carrier. This was achieved by selecting different solvents and varying concentrations of zinc precursor solutions. The composite was then blended with 50 wt% paraffin wax to investigate its electromagnetic parameters and absorptive properties. Results indicate optimal absorption performance occurs in a mixed solvent of deionized water: anhydrous ethanol = 1:1, with a zinc oxide precursor concentration of 0.2 mol/L. At a sample thickness of 2.5 mm, the minimum reflection loss reaches −40.15 dB, and the effective absorption bandwidth spans 2.88 GHz (8.00–10.88 GHz). The synergistic design strategy of “hydroxylated carrier-flower-like structure-mixed solvent” provides an innovative and practical new pathway for preparing high-performance zinc oxide/multi-walled carbon nanotube absorber materials.