Ultrathin bismuth exhibits promising performance for topological insulators due to its narrow band gap and intrinsic strong spin–orbit coupling, as well as for energy-related applications because of its electronic and mechanical properties. However, large-scale production of 2D sheets via liquid-phase exfoliation as an established large-scale method is restricted by the strong interaction between bismuth layers. Here, a sonication method is utilized to produce ultrahigh-aspect-ratio bismuthene microsheets. The studies on the mechanism excludes the exfoliation of the layered bulk bismuth and formation of the microsheets is attributed to the melting of spherical particles (r = 1.5 µm) at a high temperature—generated under the ultrasonic tip—followed by a recrystallization step producing uniformly-shaped ultrathin microsheets (A = 0.5–2 µm2, t: ≈2 nm). Notably, although the preparation is performed in oxygenated aqueous solution, the sheets are not oxidized, and they are stable under ambient conditions for at least 1 month. The microsheets are used to construct a vapor sensor using electrochemical impedance spectroscopy as detection technique. The device is highly selective, and it shows long-term stability. Overall, this project exhibits a reproducible method for large-scale preparation of ultrathin bismuthene microsheets in a benign environment, demonstrating opportunities to realize devices based on bismuthene.
Bibliographical noteFunding Information:
M.P. acknowledges the financial support of Grant Agency of the Czech Republic (EXPRO: 19?26896X). The authors thank Zdenek Sofer for his help with TEM. S.M.B.M., Y.Y., and J.P. acknowledge support by supported by the project Advanced Functional Nanorobots (reg. No. CZ.02.1.01/0.0/0.0/15_003/0000444 financed by the EFRR). This research has also been financially supported by the Ministry of Education, Youth and Sports of the Czech Republic under the Project CEITEC 2020 (LQ1601) (Y.Y.).
All Science Journal Classification (ASJC) codes
- Materials Science(all)