Functionalization of mesoporous carbons derived from pomelo peel as capacitive electrodes for preferential removal/recovery of copper and lead from contaminated water
Functionalization of mesoporous carbons derived from pomelo peel as capacitive electrodes for preferential removal/recovery of copper and lead from contaminated water
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DOI：
10.1016/j.cej.2022.134508
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发表时间：
2022-01-14
影响因子：
15.1
通讯作者：
Xu, Zhenghe
中科院分区：
文献类型：
--
作者：
Lu, Jiming;Mishra, Prashant Kumar;Xu, Zhenghe
水不仅是维持生命所需的宝贵资源，也是许多工程过程中不可或缺的成分，这不可避免地导致大量水受到污染。为了实现安全排放并回收有价值的“污染物”，需要性能更好的吸附剂来快速有效地净化水，同时产生最少的二次废物。以柚子皮为原料制备了吡咯-N（BNC-5电极）和吡啶-N（BNC-6电极）功能化的生物吸附剂，以提高对Pb 2+和Cu 2+的电吸附和选择性。软酸离子（Pb 2+）与软碱位的相互作用（pyrrolic-N）的加入促进了强的化学吸附，在1.2 V的外加电压下，Pb 2+的电吸附容量提高到2.0 mmol g（-1）。（0.077 g mg（-1）min（-1）Pb 2+），BNC-5吸附剂表现优于使用石墨烯制备的其他N掺杂吸附剂。BNC-5对外加电压响应的大的吸附-脱附滞后证实了化学吸附的本质。结果表明，通过将施加电压降低至0 V，仅32.4%的吸附离子从吸附剂解吸，但在-0.8V时达到几乎完全解吸（98.5%的吸附离子）。当以吸附-解吸循环模式操作时，BNC-5在约400次循环后保持容量保持率80%。在400次循环后，仅通过吸附剂的温和化学洗涤（0.1M HNO 3），电极容量几乎完全恢复（98.7%），并且保持循环性能。该研究证明了吸附剂在1200个循环中的稳健性，因此有可能成功地将废物转化为高性能材料，用于使用CDI的污染废水的大规模修复策略。
Water is not only a valuable resource that is needed to sustain life, but also an essential ingredient in many engineering processes, which unavoidably leads to large volumes of water being contaminated. To achieve safe discharge and also recover valuable "pollutants ", better performing sorbents are needed to rapidly and efficiently decontaminate water while generating minimal secondary wastes. Bio-sorbents derived from pomelo peel were functionalized with pyrrolic-N (BNC-5 electrode) and pyridinic-N (BNC-6 electrode) to enhance electroadsorption and selectivity of Pb2+ and Cu2+. The interaction between soft acid ions (Pb2+) and soft base sites (pyrrolic-N) contributed to a strong chemisorption that elevated the electroadsorption capacity to 2.0 mmol g(-1) for Pb2+ at an applied voltage of 1.2 V. With fast removal kinetics (0.077 g mg(-1) min(-1) of Pb2+), the BNC-5 sorbent performed comparably to other N-doped sorbents prepared using graphene. The large adsorption-desorption hysteresis of BNC-5 in responding to the applied electric voltage confirmed the nature of chemisorption. The results showed only 32.4% of the adsorbed ions being desorbed from the sorbent by reducing the applied voltage to 0 V, but reached almost complete desorption (98.5% of adsorbed ions) at -0.8 V. When operated in adsorption-desorption cycle mode, BNC-5 after ~ 400 cycles maintained a capacity retention & GE; 80%. After 400 cycles, the electrode capacity was almost fully restored (98.7%) by only mild chemical washing (0.1 M HNO3) of the sorbent and the cycling performance maintained. The study demonstrated the robustness of the sorbent over 1200 cycles and hence the potential to successfully convert waste into high-performance materials for large-scale remediation strategies of contaminated wastewater using CDI.