Simultaneously tuning structural defects and crystal phase in accordion-like TixO2x-1 derived from Ti3C2Tx MXene for enhanced electromagnetic attenuation

Single Ti3C2Tx MXene (MTO) materials are not suitable for electromagnetic (EM) wave absorption due to their high conductivity and impedance mismatch. To address this issue, we ingeniously took advantage of easily oxidized characteristics of Ti3C2Tx MXene to establish structural defects and multiphase engineering in accordion-like TixO2x-1 derived from Ti3C2Tx MXene by a high-temperature hydrogen reduction process for the first time. Phase evolution sequences are revealed to be Ti3C2Tx MXene/anatase TiO2 -> Ti3C2Tx MXene/rutile TiO2 -> TixO2x-1 (1 <= x <= 4) during a hydrogen reduction reaction. Benefiting from conductance loss caused by hole motion under the action of an external electric field and heterointerfaces caused by interfacial polarization, the impedance match and EM attenuation capability of accordion-like TixO2x-1 absorbers derived from Ti3C2Tx MXene are superior to that of pristine Ti3C2Tx MXene/TiO2 materials. Additionally, simulated whole radar cross section (RCS) plots in different incident angular of the Ti3C2Tx MXene/rutile TiO2 product are lower than -20 dBm(2), and the minimum RCS value can reach -43 dBm(2), implying a great potential for practical applications in the EM wave absorption. Moreover, the relationship among charges, defects, interfaces, and EM performances in the accordion-like TixO2x-1 materials is systematically clarified by the energy band theory, which is suitable for the research of other MXene-derived semiconductor absorbing composites.

Automated summary

The accordion-like TixO2x-1 derived from Ti3C2Tx MXene by a high-temperature hydrogen reduction process shows superior impedance match and electromagnetic wave absorption capability compared to pristine Ti3C2Tx MXene/TiO2 materials.