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Nanostructured Co3O4 electrocatalyst for OER: The role of organic polyelectrolytes as soft templates.

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Title: Nanostructured Co3O4 electrocatalyst for OER: The role of organic polyelectrolytes as soft templates.
Authors: Bhatti, Adeel Liaquat1 (AUTHOR), Tahira, Aneela2 (AUTHOR), Gradone, Alessandro3,4 (AUTHOR), Mazzaro, Raffaello3,5 (AUTHOR) mazzaro@bo.imm.cnr.it, Morandi, Vittorio3 (AUTHOR), aftab, Umair6 (AUTHOR), Abro, Muhammad Ishaq6 (AUTHOR), Nafady, Ayman7 (AUTHOR), Qi, Kezhen8 (AUTHOR), Infantes-Molina, Antonia9 (AUTHOR), Vomiero, Alberto10,11 (AUTHOR), Ibupoto, Zafar Hussain1,2 (AUTHOR) zaffar.ibhupoto@usindh.edu.pk
Source: Electrochimica Acta. Dec2021, Vol. 398, pN.PAG-N.PAG. 1p.
Subjects: Polyelectrolytes, Oxygen evolution reactions, Carboxymethylcellulose, Water electrolysis, X-ray photoelectron spectroscopy, Surface chemistry, Hydrogen evolution reactions
Abstract: Designing an efficient electrocatalyst for the oxygen evolution reaction (OER) in alkaline media is highly needed but very challenging task. Herein, we used organic polyelectrolytes such as (carboxymethyl cellulose) CMC and polyacrylamide polymers for the growth of Co 3 O 4 nanostructures by aqueous chemical growth method. The morphology and composition studies were performed on scanning electron microscopy (SEM), energy dispersive X-ray (EDX), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM) techniques. The structural properties and the surface chemistry of the Co 3 O 4 electrocatalysts were correlated to the OER performance, and the enhancement mechanism with respect to pristine Co 3 O 4 was observed to be specifically related to the polyelectrolyte templating role. Co 3 O 4 @CMC composites displayed reduced crystallite size, producing OER overpotential as low as 290 mV at 10 mAcm−2 in 1.0 KOH and Tafel slope of 71 mVdec−1, suggesting fast transfer of intermediates and electrons during water electrolysis. On the other hand, the use of polyacrylamide and its different templating mechanism resulted in similar crystallite size, but preferential exposed faces and larger surface vacancies content, as demonstrated by HR-TEM and XPS, respectively. Consistently, this material displays cutting-edge OER performance, such as overpotential of 260 mV at 10 mAcm−2 and a low Tafel slope of 63 mVdec−1. The proposed strategy for the preparation of Co 3 O 4 nanostructures in the presence of CMC and polyacrylamide is facile, mass production, thus it could equally contributed towards the realization of hydrogen energy. Therefore, these nanostructures of Co 3 O 4 can be regarded as an alternative and promising materials for the different electrochemical applications including fuel cells, metal air batteries, overall water electrolysis and other energy storage devices. [ABSTRACT FROM AUTHOR]
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Database: Engineering Source
Description
Abstract:Designing an efficient electrocatalyst for the oxygen evolution reaction (OER) in alkaline media is highly needed but very challenging task. Herein, we used organic polyelectrolytes such as (carboxymethyl cellulose) CMC and polyacrylamide polymers for the growth of Co 3 O 4 nanostructures by aqueous chemical growth method. The morphology and composition studies were performed on scanning electron microscopy (SEM), energy dispersive X-ray (EDX), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM) techniques. The structural properties and the surface chemistry of the Co 3 O 4 electrocatalysts were correlated to the OER performance, and the enhancement mechanism with respect to pristine Co 3 O 4 was observed to be specifically related to the polyelectrolyte templating role. Co 3 O 4 @CMC composites displayed reduced crystallite size, producing OER overpotential as low as 290 mV at 10 mAcm−2 in 1.0 KOH and Tafel slope of 71 mVdec−1, suggesting fast transfer of intermediates and electrons during water electrolysis. On the other hand, the use of polyacrylamide and its different templating mechanism resulted in similar crystallite size, but preferential exposed faces and larger surface vacancies content, as demonstrated by HR-TEM and XPS, respectively. Consistently, this material displays cutting-edge OER performance, such as overpotential of 260 mV at 10 mAcm−2 and a low Tafel slope of 63 mVdec−1. The proposed strategy for the preparation of Co 3 O 4 nanostructures in the presence of CMC and polyacrylamide is facile, mass production, thus it could equally contributed towards the realization of hydrogen energy. Therefore, these nanostructures of Co 3 O 4 can be regarded as an alternative and promising materials for the different electrochemical applications including fuel cells, metal air batteries, overall water electrolysis and other energy storage devices. [ABSTRACT FROM AUTHOR]
ISSN:00134686
DOI:10.1016/j.electacta.2021.139338