Ti₃C₂T_x (MXene) materials with multilayered structures have been widely developed in various academic fields. However, the application of electromagnetic wave (EMW) absorption is limited because of the high conductivity, which leads to impedance mismatch. Herein, the impedance-matching properties were optimized by loading highly defective TiO₂ onto an MXene sheet with S-doping and high-temperature annealing treatment. This treatment enhanced the EMW absorption because of the synergistic effect between the appropriate conductivity and enhanced polarization. The results show that S-doped MXene-300 has a conductivity of 2.70 × 10^–5 S/cm and exhibits the best area of impedance matching among the investigated samples. When the as-prepared S-doped MXene-300 quality ratio with paraffin was 1:1, the minimum reflection loss could reach −44.91 dB with a 4 mm coating thickness. In addition, the widest effective absorption (reflection loss ≤–10 dB) frequency bandwidth was 5.88 GHz when the thickness was 2.5 mm, which indicated that the dipolar polarization is the main positive EMW attenuation pathway for the S-doped MXene absorber. This research provides a new means of developing high-performance MXene EMW absorbers with adjustable conductivity and dielectric loss.

具有多层结构的Ti ₃ C ₂ T _x (MXene)材料已在各个学术领域得到广泛的发展。然而，电磁波（EMW）吸收的应用由于其高电导率而受到限制，从而导致阻抗失配。在此，通过将高度缺陷的 TiO ₂负载到具有 S 掺杂和高温退火处理的 MXene 片上来优化阻抗匹配特性。由于适当的电导率和增强的极化之间的协同效应，这种处理增强了 EMW 吸收。结果表明，掺杂 S 的 MXene-300 的电导率为 2.70 × 10 ^–5S/cm 并在所研究的样品中表现出最佳的阻抗匹配区域。当制备的 S 掺杂 MXene-300 与石蜡的质量比为 1:1 时，最小反射损耗可达到 -44.91 dB，涂层厚度为 4 mm。此外，当厚度为 2.5 mm 时，最宽的有效吸收（反射损耗≤–10 dB）频率带宽为 5.88 GHz，这表明偶极极化是 S 掺杂 MXene 吸收器的主要正 EMW 衰减路径。这项研究为开发具有可调电导率和介电损耗的高性能 MXene EMW 吸收器提供了一种新方法。