The highly nitrogen-doped porous carbon materials for peroxide generation and di-valent iron regeneration were synthesized by the pyrolysis of ionic-liquid, which are precursor of carbon and nitrogen, using a silica nanoparticle template. In acidic solution, both of two/four electron oxygen reduction reaction (ORR) activities of ionic-liquid derived nitrogen-doped carbon catalyst increased significantly with pyridinic/graphitic N ratio in their structure. From the cyclic voltammogram, we confirmed that di-valent/tri-valent iron redox property enhanced with increasing surface carbonyl functional group, formed during removal of silica template. The degradation experiments of azo-dye and trace pharmaceutical compounds showed that the Fenton reaction (hydroxyl radical formation) drastically increased when double working electrodes (electrode 1: peroxide generation, electrode 2: di-valent iron regeneration) were used at the same time, and as a result, the removal efficiency was drastically increased. Based on the physical/electrochemical analysis, the ionic-liquid is a candidate precursor of highly nitrogen-doped carbon as energy effective electro-Fenton catalyst.

Acknowledgements

This work was supported by the Korea Ministry of Environment as a “Global Top Project” (Project No. 2016002190003).