Tailoring the properties of aqueous–ionic liquid interfaces for tunable synthesis and self-assembly of ZnS nanoparticles

In this work, a facile strategy was developed for tunable synthesis and assembly of ZnS nanoparticles at ionic liquid (IL)–H2O interfaces. The assembled ZnS films at different IL–H2O interfaces were characterized and analyzed by scanning electron microscopy, X-ray diffraction, selected area electron diffraction and transmission electron microscopy. It was found that by using ILs with different anions and/or different alkyl chain lengths of the imidazolium cations, the properties of IL–H2O interfaces could be modulated, which in turn directed the formation of flexible ZnS films with various morphologies and different crystal phases. On the basis of the controlled experiments, a possible growth mechanism was suggested for the ZnS films at IL–H2O interfaces. Furthermore, water contact angle measurements showed that the as-prepared ZnS films demonstrated adjustable wetting properties from superhydrophobicity to hydrophilicity.