Tailoring the ORR selectivity for H2O2 electrogeneration by modification of Printex L6 carbon with 1, 4-naphthoquinone: a theoretical, experimental and environmental application study. Issue 5 (21st July 2020)

• Record Type: Journal Article
• Authors: Kronka, Matheus S.; Silva, Fernando L.; Martins, Alysson S.; Almeida, Michell O.; Honório, Káthia M.; Lanza, Marcos R. V.
• Is Part Of: Materials advances. Volume 1:Issue 5(2020)
• Page Start: 1318
• Page End: 1329
• Publication Date: 2020-07-21
• Subjects: 620.11
• DOI: 10.1039/d0ma00290a
• Languages: English
• ISSNs: 2633-5409

Abstract

Abstract : Printex L6 carbon exhibited an increase in H2 O2 selectivity by modification with 1.0% (w/w) 1, 4-naphthoquinone (NQE). Abstract : The modification of carbon-based materials with electroactive organic compounds can improve the oxygen reduction reaction (ORR) efficiency toward H2 O2 electrogeneration. The present work sought to evaluate the electrochemical properties of a Printex L6 carbon matrix modified with 1, 4-naphthoquinone (NQE) and its application toward the removal of paracetamol in different advanced oxidation processes. The 1.0% NQE-modified material showed 93% selectivity for H2 O2 electrogeneration compared to 85% for the unmodified carbon matrix. Density functional theory calculations helped confirm the NQE action as an H + donor by improving the Δ G of the reaction from −277.11 kJ mol −1 for PL6C to −986.1 kJ mol −1 for the NQE-modified material. Applied at 75 mA cm −2, the modified gas diffusion electrode presented a 30% increase in H2 O2 electrogeneration compared to the unmodified electrode. Paracetamol removal followed pseudo-first-order reaction kinetics in the following order: anodic oxidation with H2 O2 electrogeneration (AO-H2 O2 ) < AO-H2 O2 /UVC < electro-Fenton (EF) < photoelectro-Fenton (PEF). The action of the NQE modifier helped enhance the ORR activity and selectivity for H2 O2 electrogeneration, thus making the material suitable for environmental application in wastewater treatment.