Synthesis, characterization and application of self-catalyzed layered double hydroxide coated carbon-felt cathode in electro-Fenton’s degradation of organic pollutants
Résumé
Electro-Fenton’s process is a well-known electrochemical advanced oxidation processes (EAOPs) for
degradation and mineralization of refractory pollutants. The nature of cathode material used in this
process is essential parameters that determine the efficiency of the process because the cathode controls
the generation and regeneration of Fenton’s reagents (i.e. H2O2 and Fe2+)1. In this study we prepared for
the first time, a layered double hydroxide (LDH) coated carbon-felt that acts as a suitable cathode in
terms of Fenton’s reagents production for electro-Fenton degradation of organic pollutants. Cobalt-iron
(Co-Fe) LDH was deposited on a raw carbon-felt via in-situ solvo-thermal process at different treatment
temperature (70 – 120 oC) and concentrations of Co2+/Fe3+. The X-ray diffraction pattern of both powder
LDH and coated carbon-felt showed a well crystalline structure with 00l characteristic peaks of LDH and
huge peak associated with carbon (Fig. 1a). The as-prepared cathode showed superior mineralization
efficiency (93% TOC removal) when compared to raw carbon-felt cathode (66%) with addition of 0.2
mM Fe2+ for treatment of acid orange II in Electro-Fenton process (Fig b). The better mineralization
obtained with as-prepared cathode is attributed to two phenomena: (i) co-catalyst effect of the Co released
from the LDH (ii) controlled/gradual release of both catalyst that eliminate waste reactions. The prepared
cathode is a suitable and promising cathode material for application in electro-Fenton process for
wastewater treatment.