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由摩尔比分别为1:2和1:8的NiCl2·6H2O和Na2B4O7·10H2O作为反应物,合成两种非晶态镍硼酸盐,同时通过水热法合成β-Ni(OH)2.化学分析和热重-微商热重法(TG-DTG)分析结果确定两种非晶态镍硼酸盐的分子组成分别为NiO·0.8B2O3·4.5H2O和NiO·B2O3·3H2O.激光拉曼(Raman)实验结果表明镍硼酸盐样品中主要存在的硼氧阴离子为B3O3(OH)52-和B2O(OH)62-.同步辐射扩展X射线吸收精细结构(EXAFS)方法对样品进行结构解析,通过数据拟合给出样品中Ni原子周围近邻配位原子种类、配位数以及原子间距离.用不同晶体结构作为标准对两种非晶态镍硼酸盐进行拟合的结果表明,样品中Ni原子周围局域结构与Ni3B2O6晶体(ICSD No.31387)中的吻合较好.Ni原子周围配位原子为O、B和Ni,对于NiO·0.8B2O3·4.5H2O,配位数分别为5.7、3.8和3.8,配位距离分别为0.208、0.263和0.311 nm;对于NiO·B2O3·3H2O,配位数分别为6.0、4.0和4.0,配位距离分别为0.207、0.262和0.310 nm.
NiCl2 · 6H2O and Na2B4O7 · 10H2O with molar ratios of 1: 2 and 1: 8, respectively, were used as reactants to synthesize two kinds of amorphous nickel borates and synthesize β-Ni (OH) 2 by hydrothermal method. Analysis and TG-DTG analysis indicated that the molecular composition of the two amorphous nickel borates were NiO · 0.8B2O3 · 4.5H2O and NiO · B2O3 · 3H2O, respectively. Laser Raman Raman) results show that the main anion of borohydride in the samples of nickel borate is B3O3 (OH) 52- and B2O (OH) 62-. The structure of the sample is analyzed by the synchrotron radiation extended X-ray absorption fine structure (EXAFS) The number, coordination number and inter-atomic distance of the neighboring coordination atoms around the Ni atom in the sample were given by the data fitting.The results of fitting the two amorphous nickel borates with different crystal structures show that in the sample The local structure around the Ni atom is in good agreement with the Ni3B2O6 crystal (ICSD No. 3187) .The coordination atoms around the Ni atom are O, B and Ni, the coordination numbers are 5.7 for NiO · 0.8B2O3 · 4.5H2O, 3.8 and 3.8, the coordination distances are 0.208, 0.263 and 0.311 nm, respectively; for NiO · B2O3 · 3H2O, the coordination numbers are 6.0, 4.0 and 4.0, respectively, and the coordination distance Do is 0.207,0.262 and 0.310 nm.