Simultaneous In Situ Formation of ZnS Nanowires in a Liquid Crystal Template by γ-Irradiation

Abstract

Semiconductor ZnS nanowires were synthesized by a direct templating route in an inverted hexagonal liquid crystal formed by oligo(ethylene oxide)oleyl ether amphiphiles, n-hexane, n-hexanol/i-propanol (2:1), and water. The final product consists of ordered nanowires with a diameter of ca. 5 nm. Most importantly, seven or more close-packed nanowires aggregate to form a regularly shaped bundle with a width of ca. 10−30 nm, duplicating the hexagonal structure of close-packed inverted micelles formed by amphiphiles. We propose a novel simultaneous in situ formation (SISF) technique to synthesize ordered ZnS nanowires by γ-irradiation at room temperature. The reaction is worth noting in that its occurrence is homogeneous and simultaneous. The structures of the inverted hexagonal liquid crystal phase and the final product were characterized by means of polarized optical microscopy (POM), XRD, XPS, TEM and EDX techniques. UV−vis and PL spectra recorded the optical properties of the ZnS nanowires. The amount of amphiphiles passivated with ZnS nanowires is ∼3.4 wt %, as determined by thermal gravimetric analysis (TGA).