LAUSR

Poly(diallydimethylammonium chloride) (PDDA) has been demonstrated to be valuable in diverse fields, such as layer-by-layer assembly and material surface modification. Herein, we report a novel application of PDDA for exfoliating bulk tungsten disulfide (WS2) into few-layer WS2 nanosheets (FL-WS2-NSs) under ultrasonication treatment. Cationic PDDA molecules were capable of firmly binding to the WS2 surface to expose quaternary ammonium moieties in water, thereby creating electrostatic repulsion between each FL-WS2-NS. The formation of FL-WS2-NSs was proven by absorption spectroscopy, high-resolution transmission electron microscopy, and atomic force microscopy. Additionally, PDDA molecules enable FL-WS2-NSs to be stable in 200 mM NaCl for more than six months without thermal-triggered nanosheet aggregation. Given that PDDA-stabilized FL-WS2-NSs (PDDA-FL-WS2-NSs) exhibit sulfur vacancy sites, thiolated boron–dipyrromethene (BODIPY) molecules were self-assembled onto the surface of PDDA-FL-WS2-NSs. As a res...