▎ 摘　　要

How to rationally design the microstructure of polymer nanocomposites to significantly improve their electromagnetic interference shielding effectiveness (EMI SE) is still a great challenge. Herein, we developed a template method for fabricating 3D porous graphene nanoplatelets/reduced graphene oxide foam/epoxy (GNPs/rGO/EP) nanocomposites, in which 3D rGO foam embedded with GNPs constructs a 3D electrical and thermal conductive network in the EP matrix. The 3D rGO framework resolves the agglomeration problem of GNPs, acts as an efficient bunch of channels for electrical transport and attenuates the entered electromagnetic wave. Benefiting from this 3D nanohybrid framework, the GNPs/rGO/EP nanocomposites containing 0.1 wt% rGO and 20.4 wt% GNPs exhibit an EMI SE value of 51 dB in the X-band range, an almost 292% improvement relative to the rGO/EP nanocomposites (approximate to 13 dB) and 240% enhancement compared with the GNPs/EP nanocomposites without 3D microstructures (approximate to 15 dB) and an excellent thermal conductivity of 1.56 W mK(-1) and electrical conductivity up to 179.2 S m(-1). This work provides a new strategy for the design of muti-functional epoxy nanocomposites for EMI shielding and efficient heat dissipation.