Anomalous absorption of electromagnetic waves by 2D transition metal carbonitride Ti3CNTx (MXene)

• Published in: Science (American Association for the Advancement of Science) Vol. 369; no. 6502; pp. 446 - 450
• Format: Journal Article
• Language: English
• Published: Washington The American Association for the Advancement of Science 24-07-2020
• Subjects: Absorption; Carbon; Carbon nitride; Circuit protection; Circuits; Crosstalk; Electrical conductivity; Electrical resistivity; Electromagnetic radiation; Electromagnetic shielding; Electronic circuits; Metal foils; Metals; Metamaterials; Microwaves; MXenes; Portable equipment; Radiation; Radio waves; Transition metals; Two dimensional materials
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aba7977

Shields up!Specialized conductive materials are used to shield or block electromagnetic radiation such as microwaves or radio waves to either prevent the escape of stray radiation or prevent interference from unwanted sources. Ideal materials should show high effective shielding while requiring a small volume or mass of material. Materials from the MXene family of two-dimensional ceramics, where M is a transition metal and X is either carbon or nitrogen, have shown excellent shielding properties. Iqbal et al. now show even better and somewhat unexpected performance from a metal carbon nitride.Science, this issue p. 446Lightweight, ultrathin, and flexible electromagnetic interference (EMI) shielding materials are needed to protect electronic circuits and portable telecommunication devices and to eliminate cross-talk between devices and device components. Here, we show that a two-dimensional (2D) transition metal carbonitride, Ti3CNTx MXene, with a moderate electrical conductivity, provides a higher shielding effectiveness compared with more conductive Ti3C2Tx or metal foils of the same thickness. This exceptional shielding performance of Ti3CNTx was achieved by thermal annealing and is attributed to an anomalously high absorption of electromagnetic waves in its layered, metamaterial-like structure. These results provide guidance for designing advanced EMI shielding materials but also highlight the need for exploring fundamental mechanisms behind interaction of electromagnetic waves with 2D materials.