Hierarchically structured cellulose aerogels with interconnected MXene networks and their enhanced microwave absorption properties

Abstract

Hierarchically structured cellulose aerogels with interconnected Mxene (Ti₃C₂T_x) networks are prepared via freeze-casting and chemical cross-linking processes. The individual MXene nanosheets are effectively combined together with cellulose to form a conductive network by covalent cross-linking and hydrogen-bond interaction. This unique structure of aerogel composites presents a low density (0.31 g cm⁻³) with excellent microwave absorption performance. The typical aerogel with its paraffin exhibits the minimum reflection loss (RL) of −43.4 dB at 11.2 GHz with a thickness of 2 mm and an effective absorption bandwidth of 4.5 GHz as a result of multiple reflection effects, conductive loss and polarization relaxation. These lightweight Ti₃C₂T_x MXene/cellulose aerogel composites are potential materials for high-performance microwave absorption applications in aeronautics.