Graphene-based sponges for electrochemical degradation of persistent organic contaminants.
Water Res
; 203: 117492, 2021 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-34365195
Graphene-based sponges doped with atomic nitrogen and boron were applied for the electrochemical degradation of persistent organic contaminants in one-pass, flow-through mode, and in a low-conductivity supporting electrolyte. The B-doped anode and N-doped cathode was capable of >90% contaminant removal at the geometric anodic current density of 173 A m-2. The electrochemical degradation of contaminants was achieved via the direct electron transfer, the anodically formed O3, and by the OH⢠radicals formed by the decomposition of H2O2 produced at the cathode. The identified transformation products of iopromide show that the anodic cleavage of all three C-I bonds at the aromatic ring was preferential over scissions at the alkyl side chains, suggesting a determining role of the π- π interactions with the graphene surface. In the presence of 20 mM sodium chloride (NaCl), the current efficiency for chlorine production was <0.04%, and there was no chlorate and perchlorate formation, demonstrating a very low electrocatalytic activity of the graphene-based sponge anode towards chloride. Graphene-based sponges were produced using a low-cost, bottom-up method that allows easy introduction of dopants and functionalization of the reduced graphene oxide coating, and thus tailoring of the material for the removal of specific contaminants.
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MEDLINE
Assunto principal:
Poluentes Químicos da Água
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En
Ano de publicação:
2021
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Article