Polydopamine (PDA) microspheres were synthesized by a facile oxidative polymerization method and used as a high-efficiency adsorbent for the removal of a cationic dye (methylene blue, MB) from aqueous solution. Characterizations of the as-synthesized PDA microspheres and FDA microspheres-MB (MB absorbed FDA microspheres) systems were performed using several techniques such as SEM, TEM, FTIR, N-2 adsorption/desorption isotherms, particle size and zeta potential analysis. The effects of initial solution pH, temperature, initial concentration, and contact time were systematically investigated. Results showed the adsorption capacity at 25 degrees C could reach up to 90.7 mg/g. Besides, adsorption kinetics showed that the adsorption behavior followed the pseudo-second-order kinetic model. The equilibrium adsorption data fitted the Langmuir isotherm well. Thermodynamic analyses showed that the adsorption was endothermic and spontaneous, and it was also a physisorption process. In addition, the possible adsorption mechanism was also proposed based on the experimental results. (C) 2014 Published by Elsevier B.V.