Magnetically recyclable Fe3O4 doped flower-like MoS2: Efficient removal of elemental mercury

Abstract

At the front end of the Electrostatic precipitator (ESP), activated carbon injection is a common method to remove mercury from flue gas, but the high cost, low efficiency and non-recyclability limit the practical application of activated carbon. MoS2, a transition metal sulfide with a two-dimensional layered structure, was found to have favourable performances in removing contaminant. In this work, Fe3O4 was successfully grown on the surface of flower-like MoS2 by two-steps hydrothermal methods. The experimental results showed that the specific surface area of MoS2/Fe3O4 (MF) was the largest when the ratio is 10 wt% (MF-10). Compared with pure MoS2, the specific surface area of MF-10 increased by 6.7467 m2/g, which was attributed to the growth of Fe3O4. At the same time, the introduction of Fe3O4 made the MF possess superparamagnetism to facilitate its retrievability under an external magnetic field. In addition, MF-10 also showed a mercury removal efficiency of almost 100%. Although the efficiency of the MF-10 has decreased after 5 cycles and 24 h, it could still maintain about 90%, revealing a stable cycle life. Due to its mercury removal performance and recyclability, MF can be considered as a favorable adsorbent for removing elemental mercury.