Advantageous\nEffects of Phase Transition-Modulated\nElectric Polarization of Hollow CuS<sub><i>x</i></sub> for\nEnhanced Electromagnetic Wave Absorption

Scrutinizing the electromagnetic wave absorption mechanism\nof sulfides\nremains a challenge due to the variability of the modulation of the\ncrystal structure of the sulfides. To take advantage of this variability,\nnanosheet-assembled Cu<sub>9</sub>S<sub>5</sub>/CN composites with\nsulfur vacancies were prepared in this study by self-assembly synthesis\nand subsequent high-temperature heat treatment. Systematic studies\nshow the phase transition-dependent induced decrease in the conductivity,\nthe defect site-induced difference in the charge density, the weakened\nvacancy formation of defect polarization loss, and the influence of\nvalence state on electric dipole polarization loss and interfacial\npolarization loss, making the optimization of the dielectric constant\na significant positive effect on the improvement of impedance matching.\nThis work provides a reliable example and theoretical guidance for\nthe crystal structure design for the preparation of a new generation\nof efficient sulfide-based wave-absorbing materials.