Constructing three-dimensional wool-spherical vanadium-doped Nb2O5 microspheres with superior electromagnetic absorption performance

Three-dimensional (3D) wool-spherical Nb2O5/V microspheres were successfully manufactured via an ultrasonic spray method, aiming to attain an optimal electromagnetic wave absorption (EWA). The introduction of the V element through doping tunes the conductivity of the Nb2O5 microspheres and promotes the formation of multiple heterogeneous interfaces, leading to enhanced polarization and conductive losses. Additionally, the formation of a 3D architecture not only promotes structural stability but also extends the pathways of the reflected and scattered electromagnetic waves (EWs), leading to a greater consumption of EW energy. Due to their good impedance matching properties and attenuation capabilities, Nb2O5/V exhibited remarkable EWA performance with a minimum reflection loss of -47.52 dB and an effective absorption bandwidth of 2.5 GHz at a thickness of 2.25 mm in the X band. This study provides a valuable reference for guiding the design of highperformance Nb2O5-based absorber materials.