Construction of heterostructured SnS2/SnS@graphene oxide composite with highly effective microwave absorption†

Abstract

Constructing electromagnetic wave (EMW) absorbers with thin thickness, strong reflection loss and wide absorption bandwidth is an effective strategy to deal with electromagnetic radiation pollution. In this work, SnS@graphene oxide (GO, SG1), SnS₂@GO (SG2) and SnS₂/SnS@GO (SG3) composites are successfully synthesized by a hydrothermal method, freeze-drying and an annealing process, respectively. The effective absorption bandwidth (EAB) of SG1 can reach 5.70 GHz (from 12.30 to 18.00 GHz) when the matching thickness is 1.68 mm. The minimum reflection loss (RL_min) of the synthesized SG2 composite is −52.79 dB, and the EAB is 6.64 GHz (11.36–18.00 GHz, matching thickness is 2.52 mm). SG3 composites show better EMW absorption properties than SG1 and SG2. The EAB can reach 7.18 GHz (10.82–18.00 GHz), and the matching thickness is 2.00 mm. The excellent EMW absorption performance of SG3 is attributed to enhanced conduction loss, dipole polarization and interface polarization. Once the EMW enters the absorber, the flower-like structure provides many reflection and scattering paths. These results indicate that SnS_x@GO composites can be used as potential candidates for efficient and broadband EMW absorbers.