Graphene-based sponges for electrochemical degradation of persistent organic contaminants

WATER RESEARCH

卷:203

Article

Baptista-Pires, Luis^1,2  Norra, Giannis-Florjan^1,2  Radjenovic, Jelena^1,3 

[1] Catalan Inst Water Res ICRA, Emili Grahit 101, Girona 17003, Spain

[2] Univ Girona, Girona, Spain

[3] Catalan Inst Res & Adv Studies ICREA, Passeig Lluis Co 23, Barcelona 08010, Spain

关键词: Reduced graphene oxide-coated sponge;    Atomic-doped graphene;    Electrochemical water treatment;    Chlorine-free electrochemical system;    Organic pollutants;   

DOI  :  10.1016/j.watres.2021.117492

来源: Elsevier

【 摘 要 】

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 O-3, and by the OH center dot 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 pi-pi 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.

【 授权许可】

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