▎ 摘　　要

Ultralight, flexible and high-performance electromagnetic-interference (EMI) shielding performance materials are urgently required in the areas of aircraft/aerospace, portable and wearable smart electronics. Benefiting from the outstanding properties of graphene and the unique architectures, 3D assembled graphene structures have been widely applied in the field of EMI-shielding. Herein, for the first time, using Si3N4 nanowires as self-sacrificial templates with the thermal decomposition characteristics, 3D graphene microtubes (3DGMTs) membrane is fabricated by plasma enhanced chemical vapor deposition (PECVD) method, exhibiting the characteristics of free-standing and flexibility. 3DGMTs membrane assembled with silicon carbide (SiC) nanocrystals decorated edge-rich vertical graphene nanosheets (VGNs) exhibits superb EMI shielding effectiveness (SE) of around 38 dB in the frequency range of 8.2 similar to 12.4 GHz at a density of 0.0036 g cm(-3) and a thickness of 1.5 mm. Considering the ultralow density and thickness, 3DGMTs membrane shows a high specific SE (SSE, defined as SE divided by mass density) of 10,556 dB cm(3) g(-1) in X-band, which far surpasses that of almost all the reported materials. Remarkably, our work not only provides a new idea for preparation of hollow tubular carbon materials for a wide range of applications, but also presents some fundamental insights for edge-rich VGNs applied in EMI shielding.