Abstract:

2D platelet like nickel nanomaterials have high anisotropy with the morphology, and have the significant application on the catalysis, magnetic recording, energy source and biological detection field. It is important to search a simple, low cost method to prepare platelet like nickel nanomaterials without any surfactant. Without any organic surfactant and other morphology control agent, thin nickel nanoplatelets were successfully prepared on the fluorine-doped tin oxide(FTO) under the hydrothermal condition. The influence of synthetic conditions on the morphology of the nanoplatelets was investigated. It is found that the concentration of nickel salt, sodium hydroxide, and ammonia and the reaction temperature have apparent influences on the morphology of the nickel nanoplatelets. The ideal nickel nanoplatelets with large lateral size and small thickness can be obtained only under optimal concentrations of both sodium hydroxide and ammonia together. Approximate two-dimensional(2D) hexgonal thin nickel nanoplatlets with a characteristic thickness of about 10 nm and the lateral feature width of about 1 μm were obtained under optimal synthetic conditions. The pH value and the reaction temperature affect the reaction speed, and finally the morphology of the nanoplatelets. At pH 10, the complexation of ammonia to the nickel ion can facilitate the 2D growth of nickel nanoplatelets.

Key words: ammonia complexation, nickel nanoplatelets, hydrothermal conditions