物理化学学报 >> 2000, Vol. 16 >> Issue (01): 55-59.doi: 10.3866/PKU.WHXB20000111

研究论文 上一篇    下一篇

γ 辐照法制硫化镍纳米非晶及其晶化

卞国柱, 殷亚东, 伏义路, 吴忠华, 胡天斗, 刘涛   

  1. 中国科技大学化学物理系,应用化学系,合肥 230026|中国科学院高能物理研究所,北京 100039
  • 收稿日期:1999-04-26 修回日期:1999-08-04 发布日期:2000-01-15
  • 通讯作者: 卞国柱

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

摘要:

以γ射线辐照硫代硫酸钠和硫酸镍的混合水溶液,所得沉淀物经乙醇多次清洗后60℃下烘干、将所得粉末样品分别在氩气氛中160—500℃焙烧4h,使用X射线衍射(XRD)及扩展X光吸收精细结构(EXAFS)分析样品的结构.结果表明,160℃以下烘于所得样品为纳米非晶,其Ni-S壳层为四配位结构,Ni—S键长为0.221nm.经300℃焙烧后,非晶转变为NIS微晶,Ni-S壳层变为八面体六配位(红镍矿型)结构,Ni—S键长增加至0238nm.进一步提高焙烧温度时,所形成NiS晶粒逐渐长大,对经500℃焙烧样品,X射线衍射检测到很尖锐的对应单一NiS物种的衍射峰.

关键词: &gamma, 辐照, 硫化镍纳米粉末, 结构, X射线衍射, EXAFS

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