SOLUTION PLASMA SYNTHESIZED NICKEL OXIDE NANOFLOWERS: AN EFFECTIVE NO2 SENSOR

Abstract Nickel oxide (NiO) nanoflowers were successfully prepared, for the first time, from a mixture of Ni(NH 3 ) 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 , NO 2 , CO, toluene, NH 3 , and H 2 S at 150 °C. It was found that NiO nanoflowers are promising NO 2 sensing materials owing to their excellent response and selectivity.