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

Abstract

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.