Construction of low-frequency and high-efficiency electromagnetic wave absorber enabled by texturing rod-like TiO2 on few-layer of WS2 nanosheets

As a novel 2D transition metal sulfide material, WS2 has been proven to possess potential electromagnetic wave absorption (EMWA) property due to its peculiar electronic structure. However, the intrinsic weak impedance match and single dielectric loss domination of this material only produce high-frequency electromagnetic absorption (EMA), which is seemingly futile for the prevalent low-band 4G and 5G EMW. In this study, efforts have been made to effectively texture rod-like TiO2 semiconductor with different mass ratios on the a few layers of WS2 nanosheets via a simple step-by-step hydrothermal method. It is found that the WS2/TiO2 hybrids loaded with 10% TiO2 at a sample thickness of 5.30 mm, the minimum RL is-43.90 dB at 5.12 GHz. When the thickness of the sample is 2.00 mm, the bandwidth with RL value less than -10 dB can reach 4.70 GHz, and the effective EMA band could be adjusted in a range of 13.84 GHz (4.16-18 GHz) by increasing the thickness from 1.0 mm to 5.5 mm. It was found that the introduction of TiO2 nanosheets with high dielectric loss into the dielectric WS2 nanosheets can produce a synergistic effect. The benefits of such synergestic effect include, optimization of the EMA strength and bandwidth, and a reduction of the effective EMA frequency band from high frequency to low frequency. This study paves a new avenue for the future design of low-frequency EMA materials with high efficiency.

Automated summary

WS2/TiO2 hybrids were prepared through hydrothermal method, showing improved electromagnetic wave absorption properties for low-frequency bands. The addition of TiO2 nanosheets led to synergistic effects, enhancing EMA strength and expanding the bandwidth, ultimately reducing the effective EMA frequency band from high to low frequency. This study opens up new possibilities for designing efficient low-frequency EMA materials in the future.