ZnO nanosheets have been successfully synthesized via a novel microemulsion-mediated hydrothermal route at 80 degrees C for 12 h. The compositions and morphologies of the as-prepared nanosheets were characterized by X-ray power diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and selected-area electron diffraction analysis (SAED). Electrochemical (EA) and photoluminescence analysis (PL) were employed to study their electrochemical behaviors and optical properties. It was found that these ZnO nanosheets had a single crystal hexagonal wurtzite structure with lattice constants of a = 0.3249 nm and c = 0.5205 nm. And they exhibited a clearly electrocatalytic response, indicating that the ZnO nanosheets could accelerate electron transfer of the electrochemical probe. The PL spectrum of ZnO nanosheets exhibited an intense green-yellow luminescence at the wavelength of 569 nm, which can be ascribed to the defects related to oxygen vacancies. The formation mechanism of the nanostructures was also proposed and discussed. (c) 2011 Elsevier B.V. All rights reserved.