Abstract
Porous carbon cathode (PCF) was fabricated by thermal treatment at high temperature under a nitrogen gas flow mixed with 1% of oxygen. Scanning electron microscopy results revealed a homogenous porosity covered the carbon fibres. This property improved significantly the hydrophilicity that supported the oxygen reduction reaction (ORR) in electro-Fenton process as confirmed by contact angle measurements. In addition, an increase of 700 times of the surface area is observed after the thermal treatment. The crystalline average size of the new material was also ameliorated during thermal treatment as observed by X-ray diffraction pattern (XRD) due to the selective etching of amorphous carbon. Porous cathode exhibited also better electrochemical performances than raw carbon felt cathode as proved by cyclic voltammograms (CVs) because of the higher electroactive surface area. According to the Randles-Sevcik formula, the electroactive surface area of PCF was 10 times higher than raw CF. The concentration of H2O2 on PCF and raw CF was 24.6, 7.9 mg L-1 respectively after 80 min. The porous cathode was applied for removal of paracetamol (PCM) in acidic aqueous medium using an electro-Fenton process. Mineralization of PCM was followed by total organic carbon (TOC) measurements and an improvement of 31% was observed compared to the non-modified cathode after 2 h of electrolysis. The porous carbon cathode kept its stability after 10 cycles.