Construction of a 3D spider web structure with spherical Ho2O3 wrapped by carbon nanofibers for high-efficiency microwave absorption and corrosion protection

Reasonable composition control and microstructure design are the effective ways to realize multi-functional high-performance absorbing materials. In this work, a three-dimensional (3D) spider web structure was designed by the electrospinning and high temperature carbonization technology, where Ho2O3 spheres were wrapped by carbon nanofibers. Herein, the spherical Ho2O3 were surrounded by layers of carbon nanofibers (spider silk), which were like the preys inside the spider's web. This unique bionic structure working in conjunction with the tuned components enables the as-prepared composites with improved impedance matching and enhanced loss capacity. The superior electromagnetic wave absorption performance was obtained as the minimum reflection loss of -61.37 dB at 2.90 mm and the maximum effective absorption bandwidth of 6.88 GHz (11.12-18 GHz) at 2.64 mm. At a thickness of 3.44 mm, the effective absorption bandwidth is 4.80 GHz (8-12.80 GHz), covering the entire X-band. At the same time, the composite soaked in the corrosive medium for 7 days owns a low corrosion current density (10(-4) similar to 10(-6) A cm(-2)) and a high polarization resistance (10(5)similar to 10(7) Omega), which exhibits the obvious anticorrosion ability. This work designs a specific spider web structure with high-performance microwave absorption and corrosion protection.