Hierarchically porous aerogels with heterogeneous nanodomains constructed from sub-1 nm nanowires for efficient microwave absorption

Engineering hierarchically porous and heterogeneous interfaces is a powerful strategy for obtaining high-performance microwave absorbers, because it simultaneously improves impedance matching and enhances polarization loss. However, the coordinated construction of both macro-/micro pore structures and a heterogeneous skeleton in a single-material system remains a significant challenge. Inspired by the intricate architecture of butterfly wings, the aerogels featuring aligned micro-channels and periodic nanoscale ridges were constructed from Gadolinium (Gd) and Bismuth (Bi)-based sub-1 nm nanowires via freeze casting. The coexistence of cellular pores and porous cell walls optimizes the impedance matching and promotes multiple scattering, while the internal nanodomain, comprising an amorphous phase alongside crystalline Gd₂MoO₆ and Bi, creates synergistic Schottky and amorphous/crystalline heterointerfaces. These interfaces enable substantial charge transfer and redistribution, thereby generating interfacial dipoles and intensifying Maxwell-Wagner polarization. Consequently, the-optimized aerogel exhibits a maximum effective absorption bandwidth of 8.3 GHz and a minimum reflection loss of −57.6 dB. This work pioneers the use of sub-1 nm nanowires as building blocks for the in situ construction of hierarchically porous aerogels with heterogeneous nanodomains, paving the way for advanced microwave absorption materials.