Boosted electromagnetic wave absorption performance from vacancies, defects and interfaces engineering in Co(OH)F/Zn_0.76Co_0.24S/Co₃S₄ composite

The vacancies, defects and interfaces engineering is a powerful approach to regulate electromagnetic (EM) parameters and enhance absorption ability, but has not been completely elucidated, especially in binary metal sulfides (BMS). Herein, to get deeper insight into such mentioned-above engineering in boosting EMW absorption ability, two different strategies are presented and compared. Namely, a simple oxidation and scalable solvothermal sulfuration approaches are conducted to respectively synthesize the corresponding ZnCo₂O₄/ZnO composites and Co(OH)F/Zn_0.76Co_0.24S/Co₃S₄ composites. Especially, employing a series of characterization techniques, we pioneer to directly discover that a large number of sulfuration-induced sulfur vacancies observed by XPS, lattice defects and heterogeneous interfaces evidenced by HR-TEM, Raman and PL spectra are responsible for the enhanced polarization loss and conduction loss of Co(OH)F/Zn_0.76Co_0.24S/Co₃S₄. Therefore, the remarkable validity of sulfuration strategy for elevating EMW absorption ability by vacancies, defects and interfaces is revealed in comparison with oxidation tactic, which is largely significant in optimizing the EMW absorption capacity.