MoS₂ Nanosheets with Widened Interlayer Spacing for High‐Efficiency Removal of Mercury in Aquatic Systems

Abstract

Molybdenum disulphide (MoS2) has been an attractive target for investigations in the fields of catalysis, sensing, energy storage, electronics, and optoelectronics. However, its potential application in the important area of environmental cleanup has not yet been effectively explored. With an intrinsically sulfur‐rich characteristic and unique 2D structure, MoS2 should be capable of mercury capture and removal. However, successful attempts to apply MoS2 to mercury removal are quite rare, presumably because the vast majority of sulfur atoms are located inside the bulk of MoS2 and are therefore inaccessible for mercury ions. Here, the first experimental evidence that MoS2 nanosheets with widened interlayer spacing are capable of mercury capture, with an extremely high mercury uptake capacity closely matching the theoretically predicted value (2506 mg g−1) and the largest distribution coefficient value (3.53 × 108 mL g−1) is provided. Remarkably, a single treatment of industrial wastewater (polyvinyl chloride industry) with this modified MoS2 could efficiently reduce the mercury concentration (126 p.p.b.) below U.S. Environmental Protection Agency limits for drinking water standards. The findings open up the possibility of expanding the applications of transition metal dichalcogenides in environmental remediation.

Interlayer Nanoarchitectonics of Two‐Dimensional Transition‐Metal Dichalcogenides Nanosheets for Energy Storage and Conversion Applications

“…Recently, a new application of MoS 2 nanosheets with expanded interlayer spacing for removing toxic Hg 2+ from wastewater has been demonstrated. [155] The MoS 2 nanosheets have an expanded interlayer spacing of 0.94 nm and the basal planes possess plenty of defects. (Figure 14A).…”

Preparation of graphene-MoS2 hybrid aerogels as multifunctional sorbents for water remediation

“…Recent studies have demonstrated that the graphenelike two-dimensional (2D) transition metal dichalcogenides (TMDs) are promising sorbents for removal of contaminants due to their unique layered structures and large surface area [19][20][21]. For example, Chao et al [22] used ultra-thin MoS 2 nanosheets to remove toxic organics.…”

Confining Free Radicals in Close Vicinity to Contaminants Enables Ultrafast Fenton‐like Processes in the Interspacing of MoS2 Membranes

“…[4] Nevertheless,t he free radical yield is primarily determined by the adsorption ability towards the active ingredients.M olybdenum disulfide (MoS 2 ), al ayered transition-metal dichalcogenide,h as been widely applied in catalysis and energy conversion. [7] Achieving high exposure of the active surfaces and edges is the key issue for efficient activation of PMS.T wo-dimensional (2D) materials with their considerable specific surface area should show ahigh exposure of surfaces and edges.To avoid their negative effect on water safety, [8] the recycling of 2D materials remains am ajor concern for their application. [6] Remarkably,t heoretical calculations predicted that the (001) edges and (100) surfaces of 1T phase MoS 2 should exhibit strong adsorption energies (E ads )towards PMS molecules.T hus MoS 2 with abundant active sites (Mo 2+ !Mo 6+ )s hould theoretically be an ideal activator for radical generation.…”

“…[5] In particular,t he strong bonding and the highly effective electron transfer induced by the SÀMoÀSb onds are crucial for its outstanding catalytic performance. [7] Achieving high exposure of the active surfaces and edges is the key issue for efficient activation of PMS.T wo-dimensional (2D) materials with their considerable specific surface area should show ahigh exposure of surfaces and edges. However, the gallery height of bulk MoS 2 is too narrow (ca.…”