Cao Wenrui, Han Muen, Lyu Lai, Hu Chun, Xiao Feng
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China.
School of Renewable Energy , North China Electric Power University , Beijing 102206 , China.
ACS Appl Mater Interfaces. 2019 May 8;11(18):16496-16505. doi: 10.1021/acsami.9b00195. Epub 2019 Apr 29.
The discharge of organic pollutants threatens the environment and health and is also a waste of organic energy. Here, the reduction state Cu (RSC) species-doped carbon-nitrogen-oxygen polymer (RSC-CNOP) is synthesized from high-temperature polymerization of a Cu-polyimide precursor, which is used as a Fenton-like catalyst and exhibits excellent performance for pollutant degradation, accompanied by the utilization of the electron energy of the pollutants. Experiments and theoretical calculations reveal the promotion mechanism. The formed Cu(RSC)-O-C(π) electron-transfer bridges in RSC-CNOP induce the bidirectional electron transfers from RSC to O and from C(π) to O (RSC → O ← π), forming the polarized reaction micro-areas (reinforced electron-rich O microcenters and electron-poor C(π) microcenters). The free electrons in electron-rich centers of RSC-CNOP are as many as ∼8 times that of the pure CNOP sample from the electron paramagnetic resonance measurement. Pollutants are oxidized by supplying electrons to electron-poor microcenters, and HO can be selectively reduced to OH (also destruct pollutants) in the electron-rich microcenter over RSC-CNOP. This work reveals that the energy and electrons of pollutants can be efficiently utilized in the Fenton-like system through constructing and reinforcing the polarized dual reaction microcenters.
有机污染物的排放威胁着环境和健康,同时也是有机能源的浪费。在此,通过铜-聚酰亚胺前驱体的高温聚合合成了还原态铜(RSC)物种掺杂的碳-氮-氧聚合物(RSC-CNOP),其用作类芬顿催化剂,在污染物降解方面表现出优异性能,同时伴随着对污染物电子能量的利用。实验和理论计算揭示了其促进机制。RSC-CNOP中形成的Cu(RSC)-O-C(π)电子转移桥诱导了从RSC到O以及从C(π)到O的双向电子转移(RSC→O←π),形成了极化反应微区(强化的富电子O微中心和贫电子C(π)微中心)。电子顺磁共振测量表明,RSC-CNOP富电子中心的自由电子数量是纯CNOP样品的约8倍。污染物通过向贫电子微中心提供电子而被氧化,并且在RSC-CNOP上,HO可以在富电子微中心被选择性还原为OH(也可破坏污染物)。这项工作表明,通过构建和强化极化双反应微中心,类芬顿体系中可以有效利用污染物的能量和电子。