Preparation and characterization of a novel KOH activated graphite felt cathode for the electro-Fenton process

• Graphite felt, activated by KOH at high temperature, was adopted as cathode for the electro-Fenton process.
• It exhibits much higher (900%) apparent rate for dimethyl phthalate degradation than raw graphite felt cathode.
• It possesses desirable stability and universality for degrading other organic contaminants.

In the present investigation, graphite felt (GF) activated by KOH at high temperature is adopted as the electro-Fenton cathode for degrading organic pollutants contained in the wastewater. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and contact angle results show that through KOH activation the raw graphite felt (RGF) could be provided with: (i) higher surface area, (ii) more oxygen-containing functional groups, and (iii) more hydrophilicity. Experimental results show that H2O2 accumulation concentration reaches the maximal value at −0.7 V of applied cathode potential and the apparent rate constant for dimethyl phthalate (DMP) degradation at the AGF-900 (optimized activation conditions: at 900 °C for 1 h) is 0.198 min−1, much higher than that (0.020 min−1) obtained at the RGF (∼900% of enhancement). In the meanwhile, AGF-900 possesses good stability without significant performance decay even after 20 reaction cycles and desirable universality for degrading other organic contaminants. Moreover, the comparison with other commonly used materials confirms the effectiveness of AGF-900 as the electro-Fenton cathode. From the obtained results it is shown that KOH activation at high temperature is a desirable way to decorate graphite felt with more functional groups and then make it more applicable as the electro-Fenton cathode to remove organic pollutants in wastewater.

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