“…However, their high loading, unsatisfactory stability, and large density seriously prevent the large-scale application. , In contrast, carbonaceous materials with low filling content, low density, high electrical conductivity, and excellent chemical stability have attracted widespread attention. − As one of the representative carbonaceous materials, graphene with a unique 2D structure possesses large surface areas associated with high electrical conductivity, which benefit the polarization mechanism and conductive mechanism for efficient microwave absorbption. , Beyond that, biomass-derived carbon materials are rather inexpensive, renewable, and eco-friendly, which also can display sheet-like morphology as graphene, and have been widely explored in supercapacitors, photocatalysis, biomedicine, electrocatalysis, as well as in microwave absorption (MA). − Despite these properties, most biomass-derived carbon materials exhibit low impedance matching due to their extremely high electrical conductivity, leading to more surface reflection rather than transmitting into the absorbent matrix for further microwaves absorbing. , To improve the absorbing capability, some groups have taken composition modulation strategy such as N doping to carbon quantum dots . Besides, Wu et al prepared a crocodile skin-like biomass hierarchical porous carbon material that showed a maximum reflection loss of −47.46 dB via KOH activation processes . Recently, we have reported the promoted absorbing performance on rice husk- and grapefruit peel-derived carbon materials, via enhancing their interfacial polarizations. , …”