Synergistic catalysis of Co₃O₄ and graphene oxide on Co₃O₄/GO catalysts for degradation of Orange II in water by advanced oxidation technology based on sulfate radicals

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• 作者：Penghui Shi ; Xianfeng Dai ; Hongai Zheng ; Dengxin Li ; Weifeng Yao ; Chenyan Hu
• 关键词：Synergistic catalysis ; Graphene oxide ; Co3O4 ; Co&ndash ; OH complexes
• 刊名：Chemical Engineering Journal
• 出版年：15 March, 2014
• 年：2014
• 卷：240
• 期：Complete
• 页码：264-270
• 全文大小：1997 K

文摘

In this study, the synergistic catalytic mechanism of Co₃O₄ and graphene oxide (GO) nanocomposite in the heterogeneous activation of peroxymonosulfate (PMS) to generate sulfate radicals was studied. The activation of Co₃O₄/GO with different Co₃O₄ loadings in the catalyst [bare graphene oxide (GO), 20% Co₃O₄/GO, 30% Co₃O₄/GO, 50% Co₃O₄/GO, 70% Co₃O₄/GO, 90% Co₃O₄/GO, 95% Co₃O₄/GO, and pure Co₃O₄] were tested though the degradation of Orange II in water. The results show that the highest performance achieved using the Co₃O₄/GO catalyst was based on a synergistic catalysis between Co₃O₄ and GO. Furthermore, a proportional relation exists between Co₃O₄ and the catalyst. The highest catalytic activity is observed when the Co₃O₄ loading was about 50% in the catalyst. Co-OH complexes form on the surface of the GO sheet through the direct interaction of Co species with nearby hydroxyl groups or through the dissociation of H₂O with Co²⁺. The formation is proposed to facilitate the heterogeneous activation of PMS. However, a high Co₃O₄ loading on the GO surface prevents the formation of Co-OH complexes, which is important in the catalytic reaction.