Pivotal role of TiO bond lengths on crystalline structure transition of sodium titanates during electrochemical deoxidation in CaCl2NaCl melt
Pivotal role of TiO bond lengths on crystalline structure transition of sodium titanates during electrochemical deoxidation in CaCl2NaCl melt
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DOI：
10.1016/j.jallcom.2017.12.148
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发表时间：
2018-03
影响因子：
6.2
通讯作者：
Yan Peng;Dong Wang;Zhi Wang;X. Gong;Mingyong Wang;Tao Qi;Fancheng Meng
中科院分区：
文献类型：
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作者：
Yan Peng;Dong Wang;Zhi Wang;X. Gong;Mingyong Wang;Tao Qi;Fancheng Meng
用循环伏安法、恒电压电解法、理论分析和计算等方法研究了在CaCl2单键氯化钠熔体中电化学脱氧过程中TiO2Ti5O14、Na2TiO3和Na2Ti3O7的晶体结构转变。循环伏安显示的Na8Ti5O14、TiO2、Na2TiO3和Na2Ti3O7的还原电位和平行恒压电解(3.1 V)显示的主要电解产物的钛的价态都表明，电还原的顺序是Na8Ti5O14、TiO2、Na2TiO3和Na2Ti3O7。此外，相应的拉曼光谱表明，Tisingle Bondo键长预计将减少如下：Na8Ti5O14>；TiO2O4>；Na2TiO3GT；Na2Ti3O7。晶体结构表明，Na8Ti5O14、TiO2TiO4、Na2TiO3和Na2Ti3O7的平均Tisingle键长度分别为1.95、1.92、1.70和1.67 ；Tisingle Bondo长度信息解释了上述电脱氧序列。此外，Na8Ti5O14和TiO2的离解能分别为6.824和8.638 eV，表明Na8Ti5O14比TiO2更容易被还原。基于Tisingle-Bondo键长的理论分析和计算与实验结果一致，揭示了Tisingle-Bondo键长在CaCl2单键-NaC l熔体电化学还原过程中对晶体结构转变的关键作用。
The crystalline structures transition of TiO2, Na8Ti5O14, Na2TiO3and Na2Ti3O7during electrochemical deoxidation in CaCl2single bondNaCl melt were investigated via cyclic voltammetry (CV), constant voltage electrolysis, theoretical analysis and calculation. Both of the reduction potential of Na8Ti5O14, TiO2, Na2TiO3and Na2Ti3O7shown in cyclic voltammogram and the valence of titanium (Ti) of main electrolytic products shown in parallel constant voltage electrolysis (3.1 V) indicate that the electro-deoxidation sequences orderly are Na8Ti5O14, TiO2, Na2TiO3and Na2Ti3O7from easy to difficult. In addition, the corresponding Raman spectrums show that the Tisingle bondO bond lengths are expected to decrease as follows: Na8Ti5O14> TiO2> Na2TiO3> Na2Ti3O7. The average Tisingle bondO bond lengths of Na8Ti5O14, TiO2, Na2TiO3and Na2Ti3O7shown in crystal structural are 1.95, 1.92, 1.70 and 1.67 Å, respectively. The Tisingle bondO lengths information explain above electro-deoxidation sequences. Furthermore, the dissociation energies of Na8Ti5O14and TiO2are 6.824 and 8.638 eV, respectively, which indicates that Na8Ti5O14is easier to be reduced than TiO2. The theoretical analysis and calculation based on Tisingle bondO bond lengths are consistent with experiment findings, which reveals that pivotal role of Tisingle bondO bond lengths on crystalline structure transition during electrochemical deoxidation in CaCl2single bondNaCl melt.