PEG-Assisted Fabrication of Single-Crystalline CuI Nanosheets: A General Route to Two-Dimensional Nanostructured Materials

CuI single-crystalline nanosheets have been prepared for the first time via a PEG-assisted aqueous solution route at room temperature. The thickness and in-plane size of the nanosheets were ca. 60−80 nm and several micrometers, respectively. The two basal surfaces of these nanosheets were (111) planes. The phase transformation temperature and the melting point decreased 8 and 12 °C compared with those of the bulk CuI, respectively. The resistance of a single CuI nanosheet was measured by using a conductive AFM tip method, and a high conductivity of 1.996 × 10-2 Ω·cm and a photoconduction phenomenon were observed. It is found that the coexistence of PEG600 and SDBS was vital to the formation of nanosheets. This simple route could be employed to synthesize more 2D nanostructures as a general process.