Copper sulfide nanosheet arrays constructed on copper skeleton for efficient elemental mercury immobilization from flue gas

Abstract

The major challenge to use metal sulfide for elemental mercury (Hg0) immobilization from coal-fired flue gas is exploiting a facile and feasible pathway to achieve its fixed-bed application. In this work, copper sulfide (Cu7S4) nanosheet arrays anchored on copper skeleton as an efficient Hg0 trap with outstanding Hg0 sequestration performance was rapidly fabricated via a facile room-temperature chemical bath deposition method. After being impregnated in the polysulfide solution, the surface of copper foam was quickly oxidized and then converted into Cu7S4 nanosheet, which tightly adhered to the macro-porous copper foam. Benefitted from well arrayed Cu7S4 nanosheet, high-permeability structure, and uniform dispersion of active sites, the as-obtained Cu7S4/Copper foam favors for its application in Hg0 immobilization under a fixed-bed circumstance. These superiorities contribute to its outstanding Hg0 removal capacity of 38.32 mg g-1and adsorption rate of 6.06 μg g−1 min−1, far transcending that of commercial granular S impregnated activated carbon by magnitudes. This study not only developed an efficient Hg0 sorbent used in fix-bed scenarios but also illustrated a versatile strategy to rapidly functionalize metal skeletons with metal sulfides for vapor Hg0 immobilization from coal-fired flue gas.