Edge-Enriched Molybdenum Disulfide Ultrathin Nanosheets with a Widened Interlayer Spacing for Highly Efficient Gaseous Elemental Mercury Capture.

Transition metal sulfides have exhibited remarkable advantages in gaseous elemental mercury (Hg 0 ) capture under high SO 2 atmosphere, whereas the weak thermal stability significantly inhibits their practical application. Herein, a novel N , N -dimethylformamide (DMF) insertion strategy via crystal growth engineering was developed to successfully enhance the Hg 0 capture ability of MoS 2 at an elevated temperature for the first time. The DMF-inserted MoS 2 possesses an edge-enriched structure and an expanded interlayer spacing (9.8 Å) and can maintain structural stability at a temperature as high as 272 °C. The saturated Hg 0 adsorption capacities of the DMF-inserted MoS 2 were measured to be 46.91 mg·g -1 at 80 °C and 27.40 mg·g -1 at 160 °C under high SO 2 atmosphere. The inserted DMF molecules chemically bond with MoS 2 , which prevents possible structural collapse at a high temperature. The strong interaction of DMF with MoS 2 nanosheets facilitates the growth of abundant defects and edge sites and enhances the formation of Mo 5+ /Mo 6+ and S 2 2- species, thereby improving the Hg 0 capture activity at a wide temperature range. Particularly, Mo atoms on the (100) plane represent the strongest active sites for Hg 0 oxidation and adsorption. The molecule insertion strategy developed in this work provides new insights into the engineering of advanced environmental materials.