Insights into Heterogeneous Catalysis of Persulfate Activation on Dimensional-Structured Nanocarbons
Insights into Heterogeneous Catalysis of Persulfate Activation on Dimensional-Structured Nanocarbons
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DOI：
10.1021/acscatal.5b00774
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发表时间：
2015-08-01
期刊：
影响因子：
12.9
通讯作者：
Wang, Shaobin
中科院分区：
文献类型：
--
作者：
Duan, Xiaoguang;Sun, Hongqi;Wang, Shaobin
本文首次将多种纳米碳作为无金属催化剂，用于活化过硫酸盐（PS）催化苯酚、染料及其降解中间体的氧化。单壁碳纳米管（SWCNTs）、还原氧化石墨烯（rGO）和介孔碳（CMK-8）在非均相PS活化方面表现出优异的催化活性，而富勒烯（C-60）、纳米金刚石和石墨氮化碳（g-C3N4）的催化活性较低。活性炭催化剂的催化性能优于Fe3O4、CuO、Co3O4、MnO2等金属氧化物。制备的rGO-900的活性进一步与最有效的零价铁（ZVI）电子供体竞争。表征和氧化结果表明，纳米碳的催化性能是由碳杂化、孔结构、缺陷位点和官能团（特别是羰基）的内在原子排列决定的。电子顺磁共振（EPR）谱分析结果表明，不同于均相和金属基的催化活化，碳催化剂在PS活化过程中可以起到良好的电子桥作用，直接氧化吸附水生成羟基自由基。本研究发现了几种高效的多相PS活化纳米碳，为催化活化过程提供了新的见解，为绿色修复中无金属催化剂的开发提供了一个有吸引力的策略。
A variety of dimensional-structured nanocarbons were applied for the first time as metal-free catalysts to activate persulfate (PS) for catalytic oxidation of phenolics and dyes as well as their degradation intermediates. Single-walled carbon nanotubes (SWCNTs), reduced graphene oxide (rGO), and mesoporous carbon (CMK-8) demonstrated superior catalytic activities for heterogeneous PS activation, whereas fullerene (C-60), nanodiamonds, and graphitic carbon nitride (g-C3N4) presented low efficiencies. Moreover, the carbocatalysts presented even better catalytic performances than activated carbon and metal oxides, such as Fe3O4, CuO, Co3O4, and MnO2. The activity of prepared rGO-900 was further competing to the most efficient electron donor of zerovalent iron (ZVI). Both characterization and oxidation results suggested that the catalytic performances of the nanocarbons are determined by the intrinsic atom arrangements of carbon hybridization, pore structure, defective sites, and functional groups (especially the carbonyl groups). Electron paramagnetic resonance (EPR) spectra revealed that carbocatalysts might act as an excellent electron bridge in activation of PS to oxidize adsorbed water directly to generate hydroxyl radicals, distinct from homogeneous and metal-based catalytic activation. This study discovers several efficient nanocarbons for heterogeneous PS activation, and it presents new insights into the catalytic activation processes, providing a fascinating strategy to develop metal-free catalysts for green remediation.