NiO nanosheets were successfully synthesized by a facile homogeneous precipitation method with the assistance of ethanol amine. The sample was characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electron microscopy (TEM), and nitrogen adsorption-desorption techniques. The results demonstrated that the as-prepared product was cubic NiO nanosheets with a large surface area of 170.1 m(2) g(-1). Further, the as-prepared product was used to investigate its potential application for wastewater treatment. The maximum adsorption capacity for Cr(VI) and Congo red (CR) on NiO nanosheets has been determined using the Langmuir equation and found to reach up to 48.98 and 167.73 mg g(-1), respectively. It could be concluded that NiO nanosheets with special surface features had the potential as adsorbents for wastewater treatment. (C) 2015 Elsevier B.V. All rights reserved.