CO2 to CO Electroreduction, Electrocatalytic H2 Evolution, and Catalytic Degradation of Organic Dyes Using a Co(II) meso-Tetraarylporphyrin

Mouhieddinne Guergueb; Frédérique Loiseau; Florian Molton; Habib Nasri; Axel Klein

doi:10.3390/molecules27051705

CO₂ to CO Electroreduction, Electrocatalytic H₂ Evolution, and Catalytic Degradation of Organic Dyes Using a Co(II) meso-Tetraarylporphyrin

Molecules. 2022 Mar 5;27(5):1705. doi: 10.3390/molecules27051705.

Authors

Mouhieddinne Guergueb¹, Frédérique Loiseau², Florian Molton², Habib Nasri¹, Axel Klein³

Affiliations

¹ Faculty of Sciences of Monastir, University of Monastir, Avenue de l'Environnement, Monastir 5019, Tunisia.
² Département de Chimie Moléculaire (DCM), CNRS UMR 5250, Université Grenoble Alpes, F-38000 Grenoble, France.
³ Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institute for Inorganic Chemistry, University of Cologne, 50939 Cologne, Germany.

Abstract

The meso-tetrakis(4-(trifluoromethyl)phenyl)porphyrinato cobalt(II) complex [Co(TMFPP)] was synthesised in 93% yield. The compound was studied by ¹H NMR, UV-visible absorption, and photoluminescence spectroscopy. The optical band gap Eg was calculated to 2.15 eV using the Tauc plot method and a semiconducting character is suggested. Cyclic voltammetry showed two fully reversible reduction waves at E_1/2 = -0.91 V and E_1/2 = -2.05 V vs. SCE and reversible oxidations at 0.30 V and 0.98 V representing both metal-centred (Co(0)/Co(I)/Co(II)/Co(III)) and porphyrin-centred (Por^2-/Por^-) processes. [Co(TMFPP)] is a very active catalyst for the electrochemical formation of H₂ from DMF/acetic acid, with a Faradaic Efficiency (FE) of 85%, and also catalysed the reduction of CO₂ to CO with a FE of 90%. Moreover, the two triarylmethane dyes crystal violet and malachite green were decomposed using H₂O₂ and [Co(TMFPP)] as catalyst with an efficiency of more than 85% in one batch.

Keywords: catalytic degradation of dyes; cobalt(II) porphyrins; cyclic voltammetry; electrocatalytic hydrogen evolution; electroreduction CO2 to CO.

Abstract

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