硬炭因资源丰富、结构稳定及安全性高等优势,已成为钠离子电池常用阳极材料。其中,煤基衍生硬炭受到了广泛的关注。本工作以长焰煤为碳源,硫脲为氮硫源,NaCl为模板,通过两步炭化工艺和杂原子掺杂相结合的方法合成了N和S共掺杂的煤基硬炭...硬炭因资源丰富、结构稳定及安全性高等优势,已成为钠离子电池常用阳极材料。其中,煤基衍生硬炭受到了广泛的关注。本工作以长焰煤为碳源,硫脲为氮硫源,NaCl为模板,通过两步炭化工艺和杂原子掺杂相结合的方法合成了N和S共掺杂的煤基硬炭(NSPC1200)。两步炭化过程在调节碳微晶结构和扩大层间距方面发挥了重要的作用。N和S的共掺杂调节了炭材料的电子结构,赋予其更多的活性位点;此外,引入NaCl作为模板有助于孔结构的构建,有利于电极和电解质之间的接触,从而实现Na+和电子的有效传输。在协同作用下,样品NSPC1200表现出优异的储钠能力,在20 mA g^(−1)电流密度下呈现314.2 mAh g^(−1)的可逆容量。即使在100 mA g^(−1)下循环200次,仍保持224.4 mAh g^(−1)的比容量。这项工作成功实现了策略性调整煤基炭材料微观结构的目标,最终获得了具有优异的电化学性能的硬炭阳极。展开更多
The extraction behavior of N,N′ diethyl N,N′ dibenzenyl urea (DEDBU) to Uranium? and Thorium? from nitric acid solution was studied by using xylene as diluent. The effects of aqueous HNO3 concentration and extractan...The extraction behavior of N,N′ diethyl N,N′ dibenzenyl urea (DEDBU) to Uranium? and Thorium? from nitric acid solution was studied by using xylene as diluent. The effects of aqueous HNO3 concentration and extractant concentration on the extraction distribution ratio of U? and Th? were studied, and the results show that the extraction behavior of the extractant to U? is similar to tributyl phosphate (TBP), the solvation numbers for DEDBU and TBP are two, respectively. Under the experiment condition, the extractant does not show the extraction behavior to Th?, this result exhibits that the extractant has good application to separate U? and Th?. The crystal structure of the complex UO2(NO3)2[CH2(CH2)2CONC8H17]2 was determined by single crystal X ray diffraction. Crystal data: C24H46N4O10U, triclinic, space group , a = 8.662(2)?, b = 10.07(2)?, c = 10.895(3)?, α = 103.77(2)°, β = 92.01(2)°, γ = 96.23(2)°, V = 915.7(4)?3, Mr = 934.78, Z = 1, Dc = 1.695 g·cm-3, F(000) = 462, μ = 4.495mm-1, R= 0.0250, wR = 0.0591, observed reflections 3566 (I >2σ(I)).The central uranyl ions is coordinated by six oxygen atoms, two of them are from the carbonyl groups of N,N′ diethyl N,N′ dibenzenyl urea molecules, and the other four are from two nitrate groups.展开更多
文摘硬炭因资源丰富、结构稳定及安全性高等优势,已成为钠离子电池常用阳极材料。其中,煤基衍生硬炭受到了广泛的关注。本工作以长焰煤为碳源,硫脲为氮硫源,NaCl为模板,通过两步炭化工艺和杂原子掺杂相结合的方法合成了N和S共掺杂的煤基硬炭(NSPC1200)。两步炭化过程在调节碳微晶结构和扩大层间距方面发挥了重要的作用。N和S的共掺杂调节了炭材料的电子结构,赋予其更多的活性位点;此外,引入NaCl作为模板有助于孔结构的构建,有利于电极和电解质之间的接触,从而实现Na+和电子的有效传输。在协同作用下,样品NSPC1200表现出优异的储钠能力,在20 mA g^(−1)电流密度下呈现314.2 mAh g^(−1)的可逆容量。即使在100 mA g^(−1)下循环200次,仍保持224.4 mAh g^(−1)的比容量。这项工作成功实现了策略性调整煤基炭材料微观结构的目标,最终获得了具有优异的电化学性能的硬炭阳极。
文摘The extraction behavior of N,N′ diethyl N,N′ dibenzenyl urea (DEDBU) to Uranium? and Thorium? from nitric acid solution was studied by using xylene as diluent. The effects of aqueous HNO3 concentration and extractant concentration on the extraction distribution ratio of U? and Th? were studied, and the results show that the extraction behavior of the extractant to U? is similar to tributyl phosphate (TBP), the solvation numbers for DEDBU and TBP are two, respectively. Under the experiment condition, the extractant does not show the extraction behavior to Th?, this result exhibits that the extractant has good application to separate U? and Th?. The crystal structure of the complex UO2(NO3)2[CH2(CH2)2CONC8H17]2 was determined by single crystal X ray diffraction. Crystal data: C24H46N4O10U, triclinic, space group , a = 8.662(2)?, b = 10.07(2)?, c = 10.895(3)?, α = 103.77(2)°, β = 92.01(2)°, γ = 96.23(2)°, V = 915.7(4)?3, Mr = 934.78, Z = 1, Dc = 1.695 g·cm-3, F(000) = 462, μ = 4.495mm-1, R= 0.0250, wR = 0.0591, observed reflections 3566 (I >2σ(I)).The central uranyl ions is coordinated by six oxygen atoms, two of them are from the carbonyl groups of N,N′ diethyl N,N′ dibenzenyl urea molecules, and the other four are from two nitrate groups.
