Electromagnetic wave absorption of 1T’ WTe2/SBA-15 composites in the S band enhanced through heterogeneous interfaces and defect engineering

Conductive two-dimensional (2D) materials exhibit excellent electromagnetic wave (EMW) absorption properties at high frequencies due to their high conductivity loss. However, their unsatisfactory EMW absorption at low frequencies, attributed to impedance mismatch, remains a significant challenge. In this work, high-conductivity 1T′ WTe 2 nanosheets were incorporated into insulating mesoporous channels of Santa Barbara Amorphous-15 (SBA-15) via chemical vapor deposition (CVD), resulting in the formation of 1T′ WTe 2 /SBA-15 composites. These mesoporous channels restrict the growth of 1T′ WTe 2 and hinder carrier migration cross the channels, reducing their conductivity. Meanwhile, heterogeneous interfaces were formed between 1T′ WTe 2 nanosheets and mesoporous channels of SBA-15, accompanied by defects within the 1T′ WTe 2 nanosheets. This interaction promotes dipole polarization losses, significantly enhancing the attenuation of incident EMW, particularly at low frequencies. Consequently, the effective absorption bandwidth (EAB) of 1T’ WTe 2 /SBA-15 composites within the S band reached to 0.72 GHz, ranging from 3.28 GHz to 4.0 GHz, with a minimum reflection loss (RL min ) of −26.5 dB at 3.68 GHz. Furthermore, the EAB of the composites extended to 3.92 GHz at 1.5 mm in the high-frequency range. This work introduces a novel strategy for enhancing EMW absorption performance in the S band through heterogeneous interfaces and defect engineering, driven by the limiting effects of mesoporous channels.