A new plasma-treatment system was developed for preparing a functional powdery material. The nitrogen (N)-doped titanium dioxide (TiO2) powder was prepared to determine the validity of this system. The physical properties of the plasma-treated TiO2 powder agreed with those of a sample heated at 550 degrees C in the presence of ammonia, revealing the formation of the N-doped TiO2. The absorbance in the visible region and the N contents of the plasma-treated samples depended on the plasma-treatment conditions that included the treatment time, RF power, and N-2 pressure. The specific surface areas of the samples were found to be 231-242 m(2)/g, which were similar to that of the untreated TiO2 powder (236 m(2)/g). (C) 2011 Elsevier B.V. All rights reserved.