Hydrangea-like N-doped Carbon/MoO2@SnS2 microspheres with Schottky contact: A multi-interface heterostructure for high-performance microwave absorption

Heterointerface engineering is now recognized as a powerful strategy to optimize the microwave absorption performance of dielectric materials through composition adjustment and structural design. Herein, a hydrangea-like N-doped Carbon/MoO2@SnS2 (NC/MoO2@SnS2) composite was successfully prepared by high-temperature pyrolysis and oil bath treatment. The surface of each NC/MoO2 microsphere was vertically covered with interconnected SnS2 nanosheets, forming a porous core-shell morphology. We found that the number of heterojunctions and the proportion of high-lossy phases played a decisive role in optimizing the electromagnetic parameters. By regulating the content of dielectric phases, the optimized NC/MoO2@SnS2 (S3 sample) displayed a minimum reflection loss (RLmin) of −75.0 dB at an ultrathin thickness of 1.41 mm and a wide EAB of 4.2 GHz at 1.53 mm. The enhanced microwave absorption was mainly ascribed to multiple polarization relaxation, multi-interface reflection and good impedance matching characteristics produced by this semiconductor/carbon heterostructure with dual Schottky barriers. Therefore, this work provided a feasible strategy for making full use of heterointerface engineering to design ternary semiconductor/carbon heterostructures as high-performance dielectric MAMs.