Zhang X F, Wang B, Yu J, Wu X N, Zang Y H, Gao H C, Su P C, Hao S Q
Department of Chemical Engineering, Chengde Petroleum College Xueyuan Road Chengde China
College of Material Science and Chemical Engineering, Harbin Engineering University Harbin China
RSC Adv. 2018 Jan 4;8(3):1159-1167. doi: 10.1039/c7ra10689k. eCollection 2018 Jan 2.
In this study, porous carbon (3DHPC) with a 3D honeycomb-like structure was synthesized from waste biomass corncob hydrothermal carbonization coupled with KOH activation and investigated as a capacitive deionization (CDI) electrode material. The obtained 3DHPC possesses a hierarchal macroporous and mesoporous structure, and a large accessible specific surface area (952 m g). Electrochemical tests showed that the 3DHPC electrode exhibited a specific capacitance of 452 F g and good electric conductivity. Moreover, the feasibility of electrosorptive removal of chromium(vi) from an aqueous solution using the 3DHPC electrode was demonstrated. When 1.0 V was applied to a solution containing 30 mg L chromium(vi), the 3DHPC electrode exhibited a higher removal efficiency of 91.58% compared with that in the open circuit condition. This enhanced adsorption results from the improved affinity between chromium(vi) and the electrode under electrochemical assistance involving a non-faradic process. Consequently, the 3DHPC electrode with typical double-layer capacitor behavior is demonstrated to be a favorable electrode material for capacitive deionization.
在本研究中，通过废弃生物质玉米芯水热碳化结合KOH活化合成了具有三维蜂窝状结构的多孔碳（3DHPC），并将其作为电容去离子（CDI）电极材料进行了研究。所制备的3DHPC具有分级大孔和中孔结构以及较大的可及比表面积（952 m²/g）。电化学测试表明，3DHPC电极表现出452 F/g的比电容和良好的导电性。此外，还证明了使用3DHPC电极从水溶液中电吸附去除六价铬的可行性。当对含有30 mg/L六价铬的溶液施加1.0 V电压时，与开路条件相比，3DHPC电极表现出更高的去除效率，达到91.58%。这种增强的吸附源于在涉及非法拉第过程的电化学辅助下，六价铬与电极之间亲和力的提高。因此，具有典型双层电容器行为的3DHPC电极被证明是一种用于电容去离子的优良电极材料。
