The disposal of organic pollutants is one of the important research topics. Some of the studies in this field are based on the degradation of organic pollutants with a catalytic agent. The cobalt tetraoxide/peroxymonosulfate system is an important catalytic system used for the radical degradation of organic pollutants. To increase the catalytic efficiency of such reactions, graphitization of activated carbon used as a support solid and nitrogen doping to the carbon structure are commonly used methods. In this study, cobalt tetraoxide production, N-doping and graphitization were carried out in a single step by heat treatment of activated carbon doped with the phthlocyanine cobalt (II) complex. The catalytic performance of the catalyst/ peroxymonosulfate system was investigated by changing the pH, catalyst, and PMS concentration parameters on rhodamine B and 1,3,5 trichlorophenol, which were used as models. It was seen that the catalysts had 97% activity on rhodamine B in 16 min and 100% on 1,3,5 trichlorophenol in 6 min. It was observed that the catalysts continued to show high catalytic activity for five cycles in reusability studies and had a very low cobalt leaching rate. These results are in good agreement with previously published studies. In line with these results, the synthesized N-doped graphitic carbon/Co3O4 catalyst can be used as an effective catalyst for wastewater treatments.

Treatment of wastewater containing organic pollutants in the presence of N-doped graphitic carbon and Co3O4peroxymonosulfate
    Abstract 
    Graphical abstract
    1 Introduction
    2 Experimental
        2.1 Materials and methods
        2.2 Preparation of Co–AC catalyst
        2.3 Catalytic performance of Co–AC
        2.4 Degradation of RhB and 2,4,6-TCP and other catalytic parameter experiments
    3 Results and discussion
        3.1 Characterization of the Co–AC catalyst
        3.2 Effect of catalyst concentration
        3.3 Effect of PMS concentration
        3.4 Effect of temperature on degradation of RhB
        3.5 Effect of pH
        3.6 Radical and non-radical quenching experiments
        3.7 The stability and reusability of the Co–AC catalyst
        3.8 TOC and ICP-OES analysis
        3.9 Comparison with other studies
    4 Conclusion
    Anchor 21
    References

• Hakkı Türker Akçay(Department of Chemistry, Faculty of Arts and Sciences, Recep Tayyip Erdoğan University, Rize, Turkey)
• Adem Demir(Central Research Laboratory, Application and Research Centre, Recep Tayyip Erdoğan University, Rize, Turkey)
• Zehra Özçifçi(Department of Chemistry, Faculty of Arts and Sciences, Recep Tayyip Erdoğan University, Rize, Turkey)
• Tuğrul Yumak(Department of Chemistry, Faculty of Arts and Sciences, Sinop University, Sinop, Turkey)
• Turgut Keleş(Central Research Laboratory, Application and Research Centre, Recep Tayyip Erdoğan University, Rize, Turkey)