Abstract Poor environmental robustness, especially physical damage and chemical corrosion, has remained a primary challenge in practical applications of electromagnetic (EM) wave absorbing materials. The core obstacle involves coupled trade‐offs: increasing EM filler loading enhances EM attenuation but restricts polymer healing kinetics needed for rapid self‐healing, while also increasing the susceptibility of fillers to oxidation and corrosion. This work proposes a novel photothermally driven MXene/self‐healing polyurethane (SPU) elastomer that reconciles these competing requirements. Under xenon lamp (simulated sunlight, 1000 W m −2 ), MXene's photothermal conversion effectively accelerates the reversible bond exchange and chain mobility in the SPU matrix, enabling recovery of both mechanical and EM wave absorbing properties within 30 min after damage (self‐healing rate over 70 times faster than under dark condition). Tuning MXene surface terminations further tailors its electrical structure and dielectric response, achieving an effective absorption bandwidth of 5.40 GHz at a thickness of 1.77 mm and a radar cross‐section reduction of 23.55 dB·m 2 . Meanwhile, strong hydrogen bonding interaction between SPU and surface termination passivates oxidative sites and forms a protective barrier, effectively suppressing the degradation of MXene and endowing the elastomer with excellent environmental robustness under seawater and harsh acidic/alkaline media. Overall, these findings offer a versatile design paradigm for flexible, durable and self‐healing EM wave absorbing materials with potential applications in next‐generation wearable electronics, stealth technologies, and marine protection applications. image
Xiao et al. (Mon,) studied this question.