Controllable Regulation of MoS2 Surface Atomic Exposure for Boosting Interfacial Polarization and Microwave Absorption

Atomic-level surface design of 2D materials, which benefits from their ultra-high occupancy of surface atoms, has demonstrated significant potential for regulating electronic states. Despite efforts to explore heterojunctions on 2D surfaces, the stacking-dominated surface electronic structures and their influences on dielectric polarization remain unclear. Herein, a confined growth strategy is proposed to accurately adjust the surface atom occupancy of MoS 2 nanoflakes and thereby boost the polarization-dominated microwave absorption (MA). By altering the stacking layer number from single layers to tens of layers of MoS 2 , the charge transfer from graphite substrate to MoS 2 surface atoms, accompanied by the formation of local electric fields, reaches its highest intensity at two layers and then degrades dramatically with thicker MoS 2 nanoflakes. The strengthened dielectric properties eventually enhance the MA performance, increasing the maximum absorption intensity (41.9 dB) by 346% and the effective absorption bandwidth (3 GHz) by 750%. These discoveries shed new light on the electronic modification of 2D materials and their electromagnetic functionalization.