Activation of peroxymonosulfate by magnetic nitrogen-doped graphene for the degradation of organic pollutants in water

Title : Activation of peroxymonosulfate by magnetic nitrogen-doped graphene for the degradation of organic pollutants in water

Abstract:

Developing  efficient,  low-cost  and  environmental-friendly  catalysts  is  of  great significance for heterogeneous activation of peroxymonosulfate (PMS) degradation of organic pollutants in environmental remediation and protection fields. In this study, the Co@N doped porous graphene shells structure?(Co@NC) with different carbonization temperature  (700,  800,  900 ? )  was  prepared  using  a  simple  pyrolysis  process.
Benefited  from  the  rationally  structural  design  of  the  carbon  precursor  and  post- treatment with surface engineering, the derived Co@N-C can efficiently activate PMS for  fast  decomposition  of  organic  pollutants  with  trace  cobalt  leaching  in  aqueous solution. 99.5% of TC degradation at 10 min were achieved over Co@N-C with PMS, which was faster than most carbocatalysis. Co@N-C also has an excellent long-term stability and good performance toward the pollutants degradation at a wide pH range of  3.0–9.0.  Additionally,  the  singlet  oxygen  (  1O2  )  was  identified  as  the  dominant reactive  species  rather  than  sulfate  radicals  in  Co@NC  /PMS  system  based  on  the trapping experiment and  EPR  analysis. Finally,  possible degradation pathways were proposed  based  on  LC-MS  analysis  of  the  reaction  intermediates.  The  excellent performance  can  be  attributed  to  the  synergetic  effect  of    N-doped  graphene, underlying Co nanoparticles, and the encapsulation structure in which carbon shells protect  Co  from  leaching  and  aggregation.  The  embedded  Co  NPs  also  afford  the carbocatalysts to be magnetic for an easy recycling. This study provided a new insights in catalyst design for PMS-based advanced oxidation for organic pollutants degradation in wastewater.

Biography:

Qilong Xie, grew up in China and received his master's degree from the Northwest A＆F University in 2014. After he obtained his master degree from the Northwest A＆ F University , he joined Professor D. B. Li's Laboratories at State Key Laboratory of Coal Conversion, Institute of Coal Chemistry as a research assistant in 2014, Mainly engaged   in   the   study   of   Catalytic   material   characterization   and   environmental chemistry.