Preparation and Crystallization of Nanosized Amorphous Nickel Sulfide by Using γ-irradiation Article

Bian, G, Yin, Y, Fu, Y et al. (2000). Preparation and Crystallization of Nanosized Amorphous Nickel Sulfide by Using γ-irradiation . 16(1), 58-59.



cited authors

  • Bian, G; Yin, Y; Fu, Y; Wu, Z; Hu, T; Liu, T

fiu authors

abstract

  • Nano-sized amorphous nickel sulfide has been prepared in a mixed aqueous solution of Na2S2O3 and Ni2SO4 compounds using γ-irradiation at room temperature. The obtained precipitate after γ-irradiation was washed and dried at 60°C. It was then crystallized by calcination in a flow of argon at 160-500°C, respectively. All these samples were characterized by X-ray diffraction and extended X-ray absorption fine structure (EXAFS) spectroscope. No peak is detected in the X-ray diffraction patterns of 60°C dried and 160°C calcined samples, it reveals that particles in these two samples are in amorphous states with high level of disorder. Several weak peaks are found in the pattern of 300°C calcined sample and they become stronger in that of 400°C and 500°C calcined samples. All these peaks are due to NiS compound. EXAFS results demonstrate that the nickel sulfide particles in 60°C dried sample are present in a tetrahetral structure with an average Ni-S coordination distance of 0. 221nm and a Ni-S coordination number of 4. 4, which are changed to octahedral structures with Ni-S coordination distances of about 0. 238nm and Ni-S coordination numbers of near 6. 0 after calcined at above 300°C. Both the tetrahedral species and the octahedral species exist in 160°C calcined sample.

publication date

  • December 1, 2000

start page

  • 58

end page

  • 59

volume

  • 16

issue

  • 1