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Updated: Apr 20, 2026

Scalable Syntheses of Graphene Oxide and Reduced Graphene Oxide using Cascade Design Oxidation and Highly Basic Reduction Reactions
Published on: July 3, 2025
Graphene oxide as electron shuttle for increased redox conversion of contaminants under methanogenic and
Alejandra Colunga1, J Rene Rangel-Mendez1, Lourdes B Celis1
1División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICyT), Camino a la Presa San José 2055, Col. Lomas 4ª, Sección, San Luis Potosí, SLP 78216, Mexico.
Abstract:
Graphene oxide (GO) is reported for the first time as electron shuttle to increase the redox conversion of the azo compound, reactive red 2 (RR2, 0.5mM), and the nitroaromatic, 3-chloronitrobenzene (3CNB, 0.5mM). GO (5mgL(-1)) increased 10-fold and 7.6-fold the reduction rate of RR2 and 3CNB, respectively, in abiotic incubations with sulfide (2.6mM) as electron donor. GO also increased by 2-fold and 3.6-fold, the microbial reduction rate of RR2 by anaerobic sludge under methanogenic and sulfate-reducing conditions, respectively. Deep characterization of GO showed that it has a proper size distribution (predominantly between 450 and 700nm) and redox potential (+50.8mV) to promote the reduction of RR2 and 3CNB. Further analysis revealed that biogenic sulfide plays a major role on the GO-mediated reduction of RR2. GO is proposed as an electron shuttle to accelerate the redox conversion of recalcitrant pollutants, such as nitro-benzenes and azo dyes.
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