Solution plasma synthesized nickel oxide nanoflowers: An effective NO2 sensor

Nickel oxide (NiO) nanoflowers were successfully prepared, for the first time, from a mixture of Ni(NH3)(6)(2+) and triethanolamine via a solution plasma process. The as-synthesized samples were characterized by X-ray powder diffraction, scanning electron microscopy, nitrogen adsorption-desorption isotherms and transmission electron microscopy. Based on the experimental results, a possible formation mechanism for the NiO nanoflowers was proposed. In addition, the gas responses of NiO nanoflowers were investigated towards 100 ppm of a variety of gases including H-2, NO2, CO, toluene, NH3, and H2S at 150 degrees C. It was found that NiO nanoflowers are promising NO2 sensing materials owing to their excellent response and selectivity. (C) 2012 Elsevier B.V. All rights reserved.