【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氮气氛中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．更多还原

【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 160t 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 sultide 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.更多还原