Acta Phys. -Chim. Sin. ›› 2000, Vol. 16 ›› Issue (01): 55 -59 .doi: 10.3866/PKU.WHXB20000111

• ARTICLE • Previous Articles     Next Articles

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

Bian Guo-Zhu, Yin Ya-Dong, Fu Yi-Lu, Wu Zhong-Hua, Hu Tian-Dou, Liu Tao   

  1. Department of Chemical Physics,Department of Applied Chemistry,University of Science and Technology of China,Hefei 230026|Institute of High Energy Physics,Chinese Academy of Science,Beijing 100039
  • Received:1999-04-26 Revised:1999-08-04 Published:2000-01-15
  • Contact: Bian Guo-Zhu

Abstract:

Nano-sized amorphous nickel sulfide has been prepared in a mixed aqueous solution of Na2S2O3 and Ni2SO4 compounds using r-irradiation at room temperature. The obtained precipitate after r-irradiation was washed and dried at 60℃. It was then crystallized by calcination in a now of argon at 160 -- 500℃, 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℃ dried and 160℃ 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℃ calcined sample and they become stronger in that of 400℃ and 500℃ calcined samples. All these peaks are due to NiS compound. EXAFS results demonstrate that the nickel sulfide particles in 60℃ 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℃. Both the tetrahedral species and the octahedral species exist in 160℃ calcined sample.

Key words: γ-irradiation, Nanosized amorphous nickel sulfide, Structure, X-ray diffraction, EXAFS