Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay, Guangzhou University, Guangzhou 510006, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
J Hazard Mater. 2020 Feb 5;383:121182. doi: 10.1016/j.jhazmat.2019.121182. Epub 2019 Sep 7.
Nanoscale zero-valent copper combined with Cu(II)-doped reduced graphene oxide hybrid (nZVC-Cu(II)-rGO) is synthesized through an annealing reduction process, and it shows very high activity and efficiency for removing refractory organic compounds with HO. The conversion rate for the organic pollutant in this system is ∼77 and ∼13 times higher than that in the graphene oxide (GO) and reduced graphene oxide (rGO) systems, respectively. The characterization shows that nanoscale Cu(0) and Cu(II) are generated on the rGO surface during the annealing process and they are accompanied by the COCu bonding formation between the rGO substrate and the Cu(II) species in nZVC-Cu(II)-rGO, which induces cation-π interactions on the surface, resulting in the reinforced electron-rich micro-centers formation around the nZVC-enhanced Cu(II) species and electron-poor micro-centers on rGO-aromatic rings. The generation of nanoscale Cu(0) consolidates the polarization of the dual reaction micro-centers and greatly accelerates the electron transfer of the system, thus promoting HO reduction to OH in the electron-rich micro-centers. Pollutants can obviously replace HO as the electron donors of the system and are efficiently oxidized and degraded in the electron-poor micro-centers, with their own electron energy being fully utilized in the nZVC-Cu(II)-rGO Fenton-like system.
通过退火还原过程合成了纳米零价铜与 Cu(II)掺杂还原氧化石墨烯杂化材料（nZVC-Cu(II)-rGO），其在 HO 存在下对去除难处理有机化合物具有非常高的活性和效率。该体系中有机污染物的转化率分别比氧化石墨烯（GO）和还原氧化石墨烯（rGO）体系高约 77 和 13 倍。表征表明，在退火过程中，纳米 Cu(0)和 Cu(II)在 rGO 表面生成，同时伴随着 rGO 基底与 nZVC-Cu(II)-rGO 中 Cu(II)物种之间的 COCu 键合形成，这在表面诱导了阳离子-π 相互作用，导致 nZVC 增强的 Cu(II)物种周围形成富电子微中心和 rGO-芳环上的缺电子微中心。纳米 Cu(0)的生成巩固了双反应微中心的极化，并大大加速了体系的电子转移，从而促进 HO 在富电子微中心中还原为 OH。污染物可以明显替代 HO 作为体系的电子供体，并在贫电子微中心中被有效氧化和降解，其自身的电子能量在 nZVC-Cu(II)-rGO 类 Fenton 体系中得到充分利用。
