in this paper, MnO2 nanoplates were synthesized in aqueous solution under the microwave irradiation, without using any templates, catalysts, and organic reagents. The as-prepared MnO2 nanoplates were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and thermo-gravimetric (TG) analysis, and nitrogen sorption measurements. Microwave irradiation could produce MnO2 with uniform size and well-defined shape as well as high crystallinity. On the basis of experimental results, a possible formation mechanism of MnO2 nanoplates was proposed. Furthermore, the resulting MnO2 nanoplates were found to exhibit remarkable environmental catalytic performance in degradation of Rhodamine B(RhB)in aqueous solution, indicating these MnO2 nanoplates is very promising for wastewater treatment. (c) 2008 Elsevier B.V. All rights reserved.