磁性氧化石墨电催化活性及净化印染废水效能

采用高铁酸钾作为铁前驱体和氧化剂氧化石墨矿物,原位合成磁性氧化石墨(MGO)催化剂.磁性氧化石墨与碳黑(CB)混合在碳纤维布基底上制备阴极(MGO/CB),将溶解氧还原生成活性氧(ROS)氧化处理含活性红X-3B染料的模拟废水,并采用扫描电子显微镜、X-射线衍射仪、X-射线光电子能谱、电化学手段表征磁性氧化石墨催化剂的形貌结构及电化学催化活性.结果表明,片层状MGO表面锚定着不同晶体结构的纳米氧化铁粒子,活性成分存在协同催化作用;煅烧温度对氧化铁晶相及催化活性有一定影响,煅烧温度为300 ℃时制备的MGO阴极电化学降解活性红X-3B效果最佳,在阴极直接还原作用和¹O₂、^·O₂^-等自由基作用下,4h脱色率达到100%,COD_cr去除率达到77.1%;磁性氧化石墨性能稳定,至少可重复使用9次.

Magnetic graphite oxide as efficient catalyst for electrochemical treatment of printing and dyeing wastewater

Magnetic graphite oxide (MGO) catalyst was synthesized using potassium ferrate as iron precursor and oxidizing graphite oxide mineral. It was used to fabric cathode (MGO/CB) by adding carbon black (CB) on a carbon fibre cloth substrate, which can reduce dissolved oxygen to produce reactive oxygen species (ROS) for the treatment of simulated wastewater containing reactive red X-3B dye. The morphology and electrochemical properties of MGO were measured by scan electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical working station. The surface of the lamellar MGO possessed iron oxide nanoparticles with different crystal structures. These active species showed synergistic effect in electrocatalysis. The crystal phase and catalytic activity of ferric oxide were influenced by calcination temperature. At 300^oC of calcination, MGO/CB cathode exhibited high electrochemical treatment efficiency for reactive red X-3B degradation. It was found that ¹O₂ and ^·O₂^- were dominant ROS. The decolorization reached 100% and COD_cr removal reached 77.1% in 4h of electrolysis. Magnetic graphite oxide was stable and can be reused in successive cycles.