Anodized graphite felt as an efficient cathode for in-situ hydrogen peroxide production and Electro-Fenton...

This work investigated that the graphite felt anodized by NaOH, NH₄HCO₃, or H₂SO₄ aqueous, and then as the cathode materials for in-situ hydrogen peroxide (H₂O₂) production and its employed for rhodamine B (RhB) degradation via Electro-Fenton (EF) process. At -0.60 V (vs. SCE), after 120 min electrolysis, the H₂O₂ yield by graphite felt which anodized by 0.2 M H₂SO₄ achieved up 110.5 mg L^-1 in 0.05 M Na₂SO₄ electrolyte. Compared with the raw graphite felt used for cathode, the H₂O₂ yield increased by 15.85 times under the same conditions. The results of Raman spectroscopy demonstrated that graphite felt anodized by H₂SO₄ solution can be achieved the highest defect degree. For the degradation of RhB, the cathode which anodized by H₂SO₄ solution has the highest removal rate. For the degradation rate of RhB, the effect of applied current density, Fe²⁺ ions concentration, pH value were investigated. In addition, suggested that the efficient Fe³⁺ reduction reaction on the cathode surface was an important reason of the high efficiency of RhB degradation. 5-times continuous runs indicated that the modified cathode has remarkable stability and reusability during the EF process.