Wan Zhong, Wang Jianlong
Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, China.
Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing, 100084, China.
Environ Sci Pollut Res Int. 2016 Sep;23(18):18542-51. doi: 10.1007/s11356-016-7051-0. Epub 2016 Jun 13.
A heterogeneous Fenton catalyst Ce(0)-Fe(0)-reduced graphene oxide (Ce-Fe-RGO) was synthesized with chemical reduction methods and used for degradation of sulfamethazine. The introduction of Ce and graphene increased the dispersibility of iron particles which was confirmed by SEM and TEM. The results of VSM analysis showed good magnetism of Ce-Fe-RGO. The catalyst performance was compared with other kinds of catalysts (Fe(0) and Ce(0)-Fe(0)) for degradation of sulfamethazine. The results showed that Ce(0)-Fe-RGO had good catalytic performance and adsorption. X-ray diffraction showed the change of iron oxide on catalyst surface after use. The total sulfur (TS), total nitrogen (TN), total organic carbon (TOC), and intermediates, such as small organic molecular and anion ions, were analyzed by IC under different pH conditions. Finally, the possible catalytic mechanism was tentatively proposed based on inhibitor experimental results and XPS characterization. The main active species was hydroxyl radical on catalyst surface and the transition between Ce(3+) and Ce(4+) which enhanced the reduction from Fe(3+) to Fe(2+) and formation of ·OH and ·O2 (-).
采用化学还原法合成了一种非均相芬顿催化剂铈（0）-铁（0）-还原氧化石墨烯（Ce-Fe-RGO），并将其用于磺胺二甲嘧啶的降解。铈和石墨烯的引入提高了铁颗粒的分散性，扫描电子显微镜（SEM）和透射电子显微镜（TEM）证实了这一点。振动样品磁强计（VSM）分析结果表明Ce-Fe-RGO具有良好的磁性。将该催化剂与其他类型的催化剂（Fe(0)和Ce(0)-Fe(0)）用于磺胺二甲嘧啶降解的性能进行了比较。结果表明，Ce(0)-Fe-RGO具有良好的催化性能和吸附性能。X射线衍射显示了使用后催化剂表面氧化铁的变化。在不同pH条件下，通过离子色谱（IC）分析了总硫（TS）、总氮（TN）、总有机碳（TOC）以及小分子有机分子和阴离子等中间体。最后，基于抑制剂实验结果和X射线光电子能谱（XPS）表征，初步提出了可能的催化机理。催化剂表面的主要活性物种是羟基自由基，以及铈（3+）和铈（4+）之间的转变，这增强了从铁（3+）到铁（2+）的还原以及·OH和·O2（-）的形成。
