Engineering Phase Transformation of MoS2/RGO by N-doping as an Excellent Microwave Absorber.

As a hot two-dimensional (2D) material, molybdenum disulfide has been attracting extensive attention for electromagnetic wave response applications because of its unique structure. However, the electronic conductivity of nanostructured MoS2 needs to be optimized urgently. Here, nitrogen-doped 1T@2H-MoS2/reduced graphene oxide (RGO) composites are effectively constructed by hydrothermal reaction and consecutive calcination under an NH3 atmosphere. The prepared composites possess great microwave absorption (MA) performance with an expected absorption bandwidth (4.00 GHz) at the Ku band and a maximum reflection loss value (-67.77 dB), which is much better than the performance of conventional 2H-MoS2 or 2H-MoS2/RGO. The prominent absorption property is ascribed to the (i) unique self-assemble morphology of rose-like MoS2 supported on 2D RGO; (ii) controllable crystalline phase switch between 2H and 1T; and (iii) brilliant energy attenuation caused by the intense multipolarization. Furthermore, the dominant MA mechanism is described as the local polarization motivated by the interaction between RGO and MoS2. Thus, our novel structure design provides a necessary reference to achieve optimized absorption performance based on 2D materials.