Green electrochemical modification of RVC foam electrode and improved H 2 O 2 electrogeneration by applying pulsed current for pollutant removal

Abstract

The performance of cathode on H₂O₂ electrogeneration is a critical factor that limits the practical application of electro-Fenton (EF) process. Herein, we report a simple but effective electrochemical modification of reticulated vitreous carbon foam (RVC foam) electrode for enhanced H₂O₂ electrogeneration. Cyclic voltammetry, chronoamperometry, and X-ray photoelectron spectrum were used to characterize the modified electrode. Oxygen-containing groups (72.5–184.0 μmol/g) were introduced to RVC foam surface, thus resulting in a 59.8–258.2% higher H₂O₂ yield. The modified electrodes showed much higher electrocatalytic activity toward O₂ reduction and good stability. Moreover, aimed at weakening the extent of electroreduction of H₂O₂ in porous RVC foam, the strategy of pulsed current was proposed. H₂O₂ concentration was 582.3 and 114.0% higher than the unmodified and modified electrodes, respectively. To test the feasibility of modification, as well as pulsed current, EF process was operated for removal of Reactive Blue 19 (RB19). The fluorescence intensity of hydroxybenzoic acid in EF with modified electrode is 3.2 times higher than EF with unmodified electrode, illustrating more hydroxyl radicals were generated. The removal efficiency of RB 19 in EF with unmodified electrode, modified electrode, and unmodified electrode assisted by pulsed current was 53.9, 68.9, and 81.1%, respectively, demonstrating that the green modification approach, as well as pulsed current, is applicable in EF system for pollutant removal.

Graphical abstract

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