Heterogeneous Multilayer Graphene/MoS2 Nanostructures for Enhanced Electromagnetic Shielding Performance

The development of mobile communication technology and portable electronic devices inevitably leads to electromagnetic pollution. Constructing high-performance electromagnetic shielding materials with three-dimensional porous structures is an effective strategy to address this issue. Herein, composite melamine-formaldehyde (MF) foams with multilayer structures were developed via electrostatic self-assembly and cross-linking processes. In the synthesized composite foam, modified molybdenum disulfide (C-MoS2) and graphene (GP) that undergo electrostatic self-assembly are anchored to the foam skeleton via cross-linking of sodium alginate and calcium chloride, effectively preventing aggregation. Driven by interfacial polarization at the GP/C-MoS2 heterogeneous interfaces and conduction loss within the continuous network, the composite exhibits enhanced electromagnetic wave dissipation. In addition, the multilayered interface between GP and C-MoS2 nanosheets extends electromagnetic wave transmission paths via multiple reflections and scattering. The composite foam exhibits exceptional electromagnetic shielding performance, achieving an electromagnetic interference (EMI) shielding effectiveness (SE) of 49.6 dB and a specific shielding efficiency (SSE/t) exceeding 3500 dB cm2 g–1, complemented by an excellent compressive strength and thermal stability. This work demonstrates a viable strategy for designing multifunctional electromagnetic shielding materials.