Molybdenum Disulfide Motors Exhibiting Self-Exfoliation on the Surface of Water

Abstract

Beyond the most highly studied graphene, transitional metal dichalcogenides (TMDs) are now another focus in two-dimensional (2D) materials research, due to their unique physical and electronic properties. A novel molybdenum disulfide (MoS 2 ) based motor was developed. The motor can display autonomous motion on the surface of water and undergo self-exfoliation at the same time. Large scale of 2D MoS 2 nanosheets in solution phase can be obtained through the exfoliation of sodium intercalated bulk MoS 2 . Surface tension resulting from the naphthalene distributed in the MoS 2 particles is able to propel the motion of the particles at the water surface. The Marangoni effect offers a strategy to fabricate TMD motors that can exhibit motion in an unmodified aqueous environment. The coupling of self-exfoliation and autonomous motion of the MoS 2 motor provides a new platform for applications of MoS 2 in small scale motors. As MoS 2 nanosheets have shown great potential in biomedical and environmental areas, the MoS 2 motor is envisioned to be used in sensing, cargo delivery and removal of heavy metals.