Pickering Emulsions of Self-Assembled Lead Sulfide Quantum Dots with Janus-Ligand Shells as Nanoreactors for Photocatalytic Reactions

Here we prepare Pickering emulsions with semiconductor quantum dots (QDs). Amphiphilic PbS QDs are prepared by constructing Janus-ligand shells comprised of lipophilic oleic acid and hydrophilic 4-(2,2-dicyanovinyl)cinnamic acid ligands. Upon homogenization, the QDs with Janus-ligand shells self-assemble at the water–dichloromethane interface, forming stable Pickering emulsions. The photocatalytic properties are evaluated by the photodegradation reaction of methyl orange (MO) dye molecules. Under the same conditions, MO was significantly degraded when photocatalyzed by the QD Pickering emulsions, while no degradation was observed when PbS QDs without Janus-ligand shells were employed. This work provides a guide to designing QD-based nanoreactors.