TiO_(2)/Ti_(3)C_(2)T_(x)复合材料的制备及其杂化电容脱盐特性的研究

Preparation of TiO_(2)/Ti_(3)C_(2)T_(x)Composite for Hybrid Capacitive Deionization

人口的快速增长和工业经济迅猛发展导致全球淡水资源短缺,对海水和苦咸水进行淡化是解决淡水资源短缺的有效方法。本工作通过直接煅烧Ti_(3)C_(2)T_(x)制备了TiO_(2)/Ti_(3)C_(2)T_(x)复合材料,并研究了基于TiO_(2)/Ti_(3)C_(2)T_(x)复合电极的杂化电容脱盐特性(Hybrid capacitive deionization,HCDI)。研究表明,煅烧温度对TiO_(2)/Ti_(3)C_(2)T_(x)的形貌、结构、电化学和脱盐特性有重要影响。以优化后的TiO_(2)/Ti_(3)C_(2)T_(x)作为负极,酸化活性炭(Active carbon,AC)为正极,构筑了HCDI装置。在恒压模式下,当工作电压为1.2 V时,TiO_(2)/Ti_(3)C_(2)T_(x)‖AC在初始电导率为3000μS·cm^(-1)的NaCl溶液中的脱盐容量达到23.8 mg·g^(-1)。经过20个循环后容量保持率为78%。此外,通过研究TiO_(2)/Ti_(3)C_(2)T_(x)复合电极脱盐前后的形貌和晶相发现在脱盐过程中钠离子嵌入到Ti_(3)C_(2)T_(x)的层间。

The shortage of fresh water resources resultes from the rapid growth of population and industrial development.Desalination of seawater and brackish water is an effective way to alleviate the freshwater crisis.In this work,the TiO_(2)/Ti_(3)C_(2)T_(x)composites were prepared by directly calcinating Ti_(3)C_(2)T_(x)for hybrid capacitive deionization(HCDI).The results show that the calcination temperature has a significant impact on morphology,structure,electrochemical and desalination behavior of the TiO_(2)/Ti_(3)C_(2)T_(x)composites.To constitute the full HCDI device,the optimized TiO_(2)/Ti_(3)C_(2)T_(x)and acid treated activated carbon(AC)was employed as cathode and anode,respectively.In the constant voltage mode,the salt removal capacity of TiO_(2)/Ti_(3)C_(2)T_(x)‖AC reached 23.8 mg·g^(-1)under the cell voltage of 1.2 V in NaCl solution with an initial conductivity of 3000μS·cm^(-1).After 20 cycles,the capacity retention rate remains at 78%.Besides,through exploring the morphology and crystal texture evolution of TiO_(2)/Ti_(3)C_(2)T_(x)electrodes before and after desalination,it is found that the desalination of TiO_(2)/Ti_(3)C_(2)T_(x)electrodes may be achieved due to the intercalation of sodium ions into the Ti_(3)C_(2)T_(x)interlayer.