The art of framework construction: hollow-structured materials toward high-efficiency electromagnetic wave absorption

The booming electronic technology is a pair blades sword, it has not only brought huge convenience but also the unprecedented challenges to human health, and electromagnetic pollution has been one of the most serious issues among them. Effectively addressing the deleterious effects through high-efficiency electromagnetic wave absorption materials (EWAMs) has become brook no delay. In this regard, hollow EWAMs have attracted great research interests as the main representative due to their remarkable merits. The common features involving the low density, large aspect ratio, good stability, and rich cavity endow hollow structures with unique superiorities for designing and constructing excellent EWAMs, in particular lightweight assembly, hierarchical structures, and various hybrids. In this review, the latest inspiring progress and understanding of various loss types of hollow-structured EWAMs and their hybrids are summarized in detail. The fabrication strategies, absorption properties, and attenuation mechanisms of selected achievements are illustrated and discussed. Furthermore, we focus on the interaction between structures and constituents regulation and their electromagnetic wave absorption mechanisms. Finally, the challenges and future trends of hollow EWAMs are prospected. Presenting the researchers with a general description of hollow-structured absorbers is one of the principal purposes of this review, which also can provide guidance for novel high-efficiency EWAMs.