In situ preparation of metal-free cPANI-GP electrode and catalytic performance in an electro-Fenton system

Most of the current researches still stay at attaching the catalyst to the sheet electrode through an additional binder, which is an inefficient and complicated process that also affects the stability of the electrode. In this study, porous graphite particles (GP) were used as the carrier, and in situ growth method was used to prepare PANI-GP electrodes which was carbonized to prepare a nitrogen-doped modified cPANI-GP electrode with a large specific surface area. Then controlling the carbonization temperature, 700cPANI-GP with high content of pyridinic N is prepared. GP, PANI-GP and cPANI-GP were characterized by scanning electron microscope, Raman spectroscopy, X-ray electron energy spectroscopy and nitrogen desorption adsorption. The existence of hydroxyl radical (center dot OH) was identified by electron spin resonance technique. And, the phenacetin (PNT) was used as the target pollutant to confirm the electrocatalytic performance of the particle electrode. The results show that in the electro-Fenton system with a 700cPANI-GP cathode, the degradation rate of PNT and the removal rate of COD reach 92.1% and 83.3% in 2 h, respectively, when the pH is 3 and the current density is 7 mA cm(-2). And, in the reaction system using 700cPANI-GP electrode as the cathode, the concentration of center dot OH is largest that confirm pyridinic N is the active site that activates H2O2 into center dot OH. [GRAPHICS] .

Automated summary

In this study, porous graphite particles were used as the carrier to prepare nitrogen-doped modified cPANI-GP electrodes, achieving successful degradation of phenacetin as the target pollutant.