With the fast development of modern industries, scarcity of freshwater resources caused by heavy metal pollution (i.e., Hg2+) has become a severe issue for human beings. Herein, a 3D-MoS2 sponge as an excellent absorbent is fabricated for mercury removal due to its multidimensional adsorption pathways, which decreases the biomagnification effect of methylmercury in water bodies. Furthermore, a secondary water purification strategy is employed to harvest drinkable water with the exhausted adsorbents, thus alleviating the crisis of drinking water shortage. Compared to the conventional landfill treatment, the exhausted MoS2 sponge absorbents are further functionalized with a poly(ethylene glycol) (PEG) layer to prevent the heavy metals from leaking and enhance the hydrophilicity for photothermal conversion. The fabricated evaporator displays excellent evaporation rates of ∼1.45 kg m-2 h-1 under sunlight irradiation and produces freshwater with Hg2+ under the WHO drinking water standard at 0.001 mg L-1. These results not only assist in avoiding the biodeposition effect of mercury in water but also provide an environment-friendly strategy to recycle hazardous adsorbents for water purification.
Keywords: MoS2-based sponge; mercury removal; reuse of hazardous adsorbent waste; solar steam generation; water purification.