化学气相沉积法制备高氮掺杂碳纳米笼的电容去离子性能  

Capacitive deionization of high N-doping carbon nanocages prepared by chemical vapor deposition

作　　者：薛玉红 伊尔夏提·地力夏提 古丽格娜·皮达买买提 白翔 伏桂仪 魏贤勇 何晓燕 赵红光 王艳丽 XUE Yuhong;YIERXIATI·Diixiatia;GULGINA·Pidamamatia;BAI Xiang;FU Guiyi;WEI Xianyong;HE Xiaoyan;ZHAO Hongguang;WANG Yani(Key Laboratory of Chemistry and Chemical Engineering on Heavy-Carbon Resources,Yili Normal University,Yining830046,China;The Xinjiang Coal Gasification and By-Products Comprehensive Utilization Engineering Technology Research Center,Xinjiang Qinghua Energy Group Co.,Ltd.,Yining830046,China)

机构地区：[1]伊犁师范大学化学化工学院重质碳资源化学与化工重点实验室,新疆维吾尔自治区伊宁830046 [2]新疆庆华能源集团有限公司新疆煤制天然气及副产物综合利用工程技术研究中心,新疆维吾尔自治区伊宁830046

出　　处：《洁净煤技术》2024年第7期78-86,共9页Clean Coal Technology

基　　金：新疆维吾尔自治区高校基本科研业务费基金资助项目(XJEDU2024P116);伊犁师范大学提升学科综合实力专项资助项目(22XKZY07)。

摘　　要：电容去离子(CDI)是一种基于电场力驱动的快速去除水中带电离子的新型脱盐技术,在盐水预富集和降低零排能耗方面极具潜力。但目前CDI技术受限于多孔碳电极低电吸附活性及不可控的孔结构分布导致脱盐容量和电荷效率较低,限制其进一步应用。为此,以吡啶在为碳源、碱式碳酸镁为模板剂通过化学气相沉法,构建了高活性表面、结构可控的N掺杂碳纳米笼状结构(N-CNC),探究其脱盐性能。通过精准控制载气与吡啶进入量,制备的N-CNC是由3~5层石墨化碳层层堆叠的空心长方体形貌,且外壁平均壁厚在1~2 nm,其中N质量分数高达4.2%。得益于这种优异的孔隙结构分布和丰富的表面化学性质,N-CNC展现出以赝电容贡献为主的电化学行为。组装N-CNC//N-CNC对称模块,采用单通道脱盐模式脱盐测试,结果表明,盐吸附量和电荷效率分别为21.8 mg/g和82%,能耗低至0.71 Wh/g。进一步使用自组装CDI模块处理煤化工高盐水,在1.2 V吸附电压下获得Cl^(-)、SO_(4)^(2-)和NO_(3)^(-)电吸附脱盐容量分别为33.4、20.5和8.9 mg/g,其中Cl-/SO_(4)^(2-)选择性比高达5.1。本研究提供了一种简便可控的N掺杂碳纳米笼状结构制备方法,为CDI浓缩工业卤水预富集应用提供理论和技术支撑。Capacitive deionization(CDI)is a novel desalination technology that rapidly removes charged ions from water driven by electric field force.It has great potential in brine pre-concentration and reducing the energy consumption of zero liquid discharge desalination.However,the current CDI technology is limited by the low electro-adsorption active sites and uncontrollable pore structure distribution of porous carbon electrodes,resulting in low desalination capacity and charge efficiency,which hinders its further application.Therefore,highly active surfaces and structurally controllable N-doped carbon nanocages(N-CNC)were constructed by a chemical vapor deposi-tion method using pyridine as a carbon source and alkaline magnesium carbonate as a templating agent to investigate their desalination properties.Through precise control of the carrier gas and pyridine quantities,the resulting N-CNC consists of 3-5 layers of graphi-tized carbon arranged in a hollow rectangular morphology.The average thickness of the outer wall ranges from 1 to 2 nm,with an impres-sive N content reaching up to 4.2%.Benefitting from its exceptional porous structure distribution and rich surface chemistry,N-CNC ex-hibits electrochemical behavior primarily contributed by its pseudo-capacitive properties.The desalination test results of the assembled N-CNC//N-CNC symmetric module using the single-pass desalination mode show that the salt adsorption capacity and charge efficiency are 21.8 mg/g and 82%,respectively,with low energy consumption of 0.71 Wh/g.Further treatment of coal chemical high-salinity water test show excellent anion absorption performance.Electric adsorption desalination capacity of Cl^(-),SO_(4)^(2-),NO_(3)^(-)are 33.4,20.5,8.9 mg/g,of which the selectivity ratio of Cl-/SO_(4)^(2-)is as high as 5.1.This study provides a simple and controllable preparation method for N-doped carbon nanocage structure,which provides certain theoretical and technical support for the industrialization application of CDI concentrated industrial brine.

关 键 词：吡啶 化学气相沉积法 碳纳米笼 电容脱盐 吸附量 煤化工废水 

分 类 号：TQ53[化学工程—煤化学工程] TK114[动力工程及工程热物理—热能工程]