Dimensional Design of Cellulose Aerogels with Schottky Contact for Efficient Microwave Absorption

Cellulose aerogels, as a novel class of carbon-based materials, exhibit immense potential in the field of microwave absorption (MWA) due to their biocompatibility, low density, unique porous structure, and tunable architecture. However, the development of multi-dimensional components with specialized heterogeneous structures, which are based on cellulose aerogels, remains a significant challenge. This 0D/1D/3D structural configuration facilitates tunable electromagnetic properties and favorable impedance matching. The Schottky contact at the ZnO/Ni interface, in particular, induces a strong interfacial polarization, and the multi-dimensional structural design results in multiple heterointerfaces. Density functional theory (DFT) calculations reveal that the unique Schottky contact induces a Schottky barrier that causes band bending, facilitating the directed migration of electrons at the interface and the formation of an internal electric field, thus significantly accelerating the multipolar relaxation process. As anticipated, the CCMC/ZnO@Ni aerogel exhibits a minimum reflection loss (RLmin) value of -64.0 dB at 13.9 GHz at a thickness of 2.0 mm, and its effective absorption bandwidth (EAB) reaches 4.9 GHz. This work gives valuable guidance and inspiration for the design of multi-dimensional materials that are composed of dimensional gradient structures, which holds great application potential for electromagnetic wave (EMW) attenuation.