N-Graphene-CeO2 nanocomposite enriched with Ce (III) sites to improve the efficiency of peroxone reaction under acidic conditions
N-Graphene-CeO2 nanocomposite enriched with Ce (III) sites to improve the efficiency of peroxone reaction under acidic conditions
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DOI：
10.1016/j.seppur.2019.05.065
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发表时间：
2019-10
影响因子：
8.6
通讯作者：
Yalei Ding;Bao Huijie;Ruyi Qian;Tongdong Shen;S. Tong
中科院分区：
文献类型：
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作者：
Yalei Ding;Bao Huijie;Ruyi Qian;Tongdong Shen;S. Tong
由于化学工业酸性废水的毒性和酸性较高，其处理是生物降解方法的一项艰巨任务。高级氧化工艺 (AOP) 是处理难降解废水的常用方法，但传统的芬顿和臭氧化工艺在 pH 值低于 2 时效率低下。H2O2-与臭氧的结合（称为过氧酮反应）是解决这一问题的一种潜在方法，因为其效率高且易于操作。在这项研究中，合成了一种由氮掺杂石墨烯-CeO2（NG-Ce）组成的复合材料，作为过氧酮反应中的多相催化剂，用于去除酸性溶液中的有机污染物。 X射线衍射分析和拉曼光谱证实了NG-Ce催化剂中CeO2和石墨烯的存在。采用X射线光电子能谱分析催化剂表面元素的化学成分和价态。实验结果表明，NG-Ce极大地提高了peroxone反应的氧化效率并拓宽了其工作pH范围。尽管NG-Ce/H2O2/O3的效率随着溶液酸度的增加而降低，但在pH低至0.25时污染物的降解仍然有效。 NG-Ce 表面丰富的 Ce (III) 位点被认为是 NG-Ce 在 peroxone 反应中具有高催化活性的原因。
The treatment of acidic wastewaters from chemical industries is a difficult task for biodegradation methods to deal with due to the high toxicity and acidity of the waters. Advanced oxidation processes (AOPs) are common methods used for treating refractory wastewaters, but traditional Fenton and ozonation processes are inefficient at pH values below 2. The combination of H2O2-with ozone, termed peroxone reaction, is one potential method to solve this problem because of its high efficiency and ease operation. In this study, a composite comprised of N-doped graphene-CeO2(NG-Ce) was synthesized as a heterogeneous catalyst in peroxone reaction for the removal of organic pollutants in acidic solutions. X-ray diffraction analysis and Raman spectroscopy confirmed the existence of CeO2and graphene in the NG-Ce catalyst. X-ray photoelectron spectroscopy was performed to analyze the chemical compositions and the valence states of the elements on the surface of the catalysts. Experimental results showed that NG-Ce greatly improved the oxidative efficiency of peroxone reaction and broadened its working pH range. Although the efficiency of NG-Ce/H2O2/O3is decreased as the acidity of solution increases, the degradation of pollutants remained efficient at a pH as low as 0.25. Rich Ce (III) sites on the surface of NG-Ce were suggested to be responsible for the high catalytic activity of NG-Ce in peroxone reaction.