ZnO nanoparticles coated carbon fiber composite with enhanced microwave absorption properties and light weight features

ZnO nanoparticles coated carbon fiber (ZC composite) was prepared by one-step hydrothermal method. The effects of pH of the reaction solution on the morphology, composition, electromagnetic and microwave absorption properties were investigated at the frequency range of 8.2–12.4 GHz. SEM, EDX and XRD results showed that ZnO nanoparticles are uniformly coated on the surface of carbon fibers (CF). The results of electromagnetic properties displayed that the complex permittivity and dielectric loss decrease with the increase of reaction pH on the surface of CF. The microwave absorption performance of ZC composites was enhanced with high absorption efficiency and wide bandwidth. For ZC-8 composite, the bandwidth with RL below − 10 dB reaches 3.7 GHz (8.7–12.4 GHz) at thickness of 2.5 mm and the mimum RL values reaches − 45 dB at 11.2 GHz at thickness of 2.4 mm when the content of the composite is 0.3 wt%. This study offers a facile strategy for the preparation and structure design of carbon fiber-based microwave absorption materials and can facilitate the practical application of ZC composite materials owing to its light weight features and strong absorption performance.