Low-frequency and dual-band microwave absorption properties of novel VB-group disulphides (3R–TaS2) nanosheets

Abstract

As electromagnetic technology advances and demand for electronic devices grows, concerns about electromagnetic pollution intensify. This has spurred focused research on innovative electromagnetic absorbers, particularly chalcogenides, noted for their superior absorption capabilities. In this study, we successfully synthesize 3R–TaS₂ nanosheets using a straightforward calcination method for the first time. These nanosheets exhibit significant absorption capabilities in both the C-band (4–8 ​GHz) and Ku-band (12–18 ​GHz) frequency ranges. By optimizing the calcination process, the complex permittivity of TaS₂ is enhanced, specifically for those synthesized at 1000 ​°C for 24 ​h. The nanosheets possess dual-band absorption properties, with a notable minimum reflection loss (RL_min) of −41.4 ​dB in the C-band, and an average absorption intensity exceeding 10 ​dB in C- and Ku-bands, in the absorbers with a thickness of 5.6 ​mm. Additionally, the 3R–TaS₂ nanosheets are demonstrated to have an effective absorption bandwidth of 5.04 ​GHz (3.84–8.88 ​GHz) in the absorbers with thicknesses of 3.5–5.5 ​mm. The results highlight the multiple reflection effects in 3R–TaS₂ as caused by their stacked structures, which could be promising low-frequency absorbers.