Shell-thickness-induced spontaneous inward migration of mercury in porous ZnO@CuS for gaseous mercury immobilization

Inducing gaseous substances to migrate inward into a solid material is one of the effective methods to improve the interfacial adsorption stability. However, the gaseous mercury (Hg 0 ) adsorption on bulk material, especially mineral sulfides , generally occurred on the outer surface owing to their compact structure, resulting in the low bonding stability. This study prepared porous [email protected] with different shell thickness to investigate mercury adsorption performance and bonding stability. The porous shell structure enabled Hg 0 to migrate inward into [email protected] Such an inducing effect, on one hand, improved the mercury adsorption performance due to the increase of active sites with the thickened shell. On the other hand, the mercury bonding stability was enhanced along with the increase of shell thickness. The initial mercury desorption temperature gradually increased from 50 to higher than 100 °C, and meanwhile, the desorption peak temperature increased from 150 to 275 °C. The improved bonding stability also enlarged its adaption to a wider temperature window (50–150 °C). Moreover, the optimal [email protected] has a saturated adsorption capacity of 60.53 mg/g, and it has high resistance against O 2 , SO 2, and H 2 O. This work thus offers a promising thickness-induced method to enhance the mercury bonding stability on sulfides.