Oxygen uptake by a cobalt(II) complex. An undergraduate experiment

Appleton, T. G.

doi:10.1021/ed054p443

Cited by 26 publications

(8 citation statements)

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“…Even though there are lots of artificial and natural redox mediators for Li–O 2 batteries in pure O 2 , − no O 2 carrier (or shuttle) with both O 2 -carrier ability and catalytic activity has been investigated in air (21% O 2 ). It is known that N , N ′-bis(salicylidene)ethylenediaminocobalt(II) (Co II -salen), one model compound of Schiff base complexes of Co II , can reversibly coordinate and release oxygen in the human body, − suggesting its potential electrochemical application in LABs . Such versatile Co II -salen has not ever been studied in LOBs or LABs, and it has a potential to provide a new reaction route to avoid the formation of superoxide intermediate.…”

mentioning

confidence: 99%

MCNTs@MnO₂ Nanocomposite Cathode Integrated with Soluble O₂-Carrier Co-salen in Electrolyte for High-Performance Li–Air Batteries

Wang

et al. 2017

Nano Lett.

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Li-air batteries (LABs) are promising because of their high energy density.However, LABs are troubled by large electrochemical polarization during discharge and charge, side reactions from both carbon cathode surface/peroxide product and electrolyte/superoxide intermediate, as well as the requirement for pure O2. We here report the solution using multi-wall carbon nanotubes (MCNTs)@MnO2 nanocomposite cathode integrated with N,N'-bis(salicylidene)ethylenediaminocobalt(II) (Co II -salen) in electrolyte for LABs. The advantage of such a combination is that on one hand, the coating layer of δ-MnO2 with about 2-3 nm on MCNTs@MnO2 nanocomposite catalyzes Li2O2 decomposition during charge and suppresses side reactions between product Li2O2 and MCNT surface. On the other hand, Co II -salen works as a mobile O2-carrier and accelerates Li2O2 formation through the reaciton of (Co III -salen)2-O2 2-+ 2Li + + 2e -→ 2Co II -salen + Li2O2. This reaction route overcomes the pure O2 limitation and avoids the formation of aggressive superoxide intermediate (O2 -or LiO2), which easily attacks organic electrolyte. By using this double-2 catalyst system of Co-salen/MCNTs@MnO2, the lifetime of LABs is polonged to 300 cycles at 500 mA g -1 (0.15 mA cm -2 ) with fixed capacity of 1000 mAh g -1 (0.30 mAh cm -2 ) in dry air (21% O2). Furthermore, we up-scale the capacity to 500 mAh (5.2 mAh cm -2 ) in pouchtype batteries (~4 g, 325 Wh kg -1 ). This study should pave a new way for the design and construction of practical LABs.Lithium-air batteries (LABs) have recently attracted extensive academic and technological interest due to their high theoretical energy density of ~3600 Wh kg -1 based on the electrochemical reaction pathway of 2Li + + O2 + 2e − ↔ Li2O2. [1][2][3][4][5] However, LABs still suffer from three critical issues. The first one is insufficient catalytic activities towards Li2O2 formation/decomposition, leading to large electrochemical polarizition during discharge and charge. The second one is side reactions not only between nonaqueous electrolyte and superoxide intermediate but also between carbon cathode surface and product Li2O2, [6][7][8][9] resulting in short cycling life. The third one is slow diffusion and large concentration polarization of oxygen in electrolyte, giving rise to the requirement for high-purity O2. The cathode reactions include the formation of superoxide intermediate (LiO2 or O2 -) and Li2O2 product in discharge and the decomposition of Li2O2 in charge. [10][11][12][13][14] The superoxide intermediate easily decomposes the organic electrolyte; while, the insoluble Li2O2 product that is deposited on carbon cathode tends to oxidize the defects and oxygen-containing radicals on carbon cathode surface. The inexpensive method to increase catalytic activities towards Li2O2 formation/decomposition is worth developing. However, the report on costeffective methods to prevent carbon cathode surface from side reactions and avoid the formation of superoxide intermediate is still limited.During reversib...

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confidence: 99%

MCNTs@MnO₂ Nanocomposite Cathode Integrated with Soluble O₂-Carrier Co-salen in Electrolyte for High-Performance Li–Air Batteries

Wang

et al. 2017

Nano Lett.

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“…One experiment offered by several institutions (3 of 15) is the classic cobalt(II) salen complex as a model of the oxygen binding in haemoglobin and myoglobin. [41] This coordination complex undergoes reversible oxygen binding that is readily observed by eye, but also monitored using cyclic voltammetry.…”

Section: Bioinorganic Chemistrymentioning

confidence: 99%

Advanced inorganic chemistry laboratory curricula in Australian universities: investigating the major topics and approaches to learning

et al. 2022

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The teaching laboratory remains an important environment for developing undergraduate chemists, but the inherent diversity of inorganic chemistry results in less standardised undergraduate curricula than other sub-disciplines. This study surveys the content of advanced (third-year) inorganic chemistry across Australia and reviews experimental materials from 15 universities that offer inorganic laboratory programmes at this level. All institutions offer at least one traditional inorganic experiment, the most common being the preparation and acetylation of ferrocene, spectroscopy and magnetochemistry of nickel coordination compounds and palladium-catalysed cross-couplings. These inorganic classics are complemented by a breadth of non-traditional offerings that often align with institutional research strengths. Academic unit coordinators were also surveyed and their responses interpreted using ASELL (Advancing Science and Engineering through Laboratory Learning) tools. Advanced inorganic laboratory programmes were found to develop students' practical and transferrable skills. Students generally receive guidance from teaching staff in all aspects of experimental work, including planning, development, analysis and communicating conclusions. Academic unit coordinators identified potential improvements that included diversifying student activities in the lab and how they are being assessed.

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“…Nasr-Esfahani, et al [125] undertook in 2014 a study of ligands derived from the 2,2 -ethylenebis(nitrolomethylidene)diphenol-N,N -ethylenebis(salicylimine) (salen) structure. This ligand is known to form very robust coordination complexes with Co(II), such as the famous oxygen carrier, cosalen also known as salcomine [126]. They prepared two complexes with the following ligands based on the salen structure: The group led by Udo Bach at the Monash University reported two novel ligand structures in respectively 2012-2013.…”

Section: Cobalt Mediatorsmentioning

confidence: 99%

Metal Coordination Complexes as Redox Mediators in Regenerative Dye-Sensitized Solar Cells

et al. 2019

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Dye-sensitized solar cells (DSSCs) have attracted a substantial interest in the last 30 years for the conversion of solar power to electricity. An important component is the redox mediator effecting the transport of charge between the photoelectrode and the dark counter electrode (CE). Among the possible mediators, metal coordination complexes play a prominent role and at present are incorporated in several types of devices with a power conversion efficiency exceeding 10%. The present review, after a brief introduction to the operation of DSSCs, discusses at first the requirements for a successful mediator. Subsequently, the properties of various classes of inorganic coordination complexes functioning as mediators relevant to DSSC operation are presented and the operational characteristics of DSSC devices analyzed. Particular emphasis is paid to the two main classes of efficient redox mediators, the coordination complexes of cobalt and copper; however other less efficient but promising classes of mediators, notably complexes of iron, nickel, manganese and vanadium, are also presented.

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Oxygen uptake by a cobalt(II) complex. An undergraduate experiment

Abstract: Using Co(salen) as a model compound illustrating the uptake of oxygen in hemoglobin.

Cited by 26 publications

References 10 publications

MCNTs@MnO₂ Nanocomposite Cathode Integrated with Soluble O₂-Carrier Co-salen in Electrolyte for High-Performance Li–Air Batteries

MCNTs@MnO₂ Nanocomposite Cathode Integrated with Soluble O₂-Carrier Co-salen in Electrolyte for High-Performance Li–Air Batteries

Advanced inorganic chemistry laboratory curricula in Australian universities: investigating the major topics and approaches to learning

Metal Coordination Complexes as Redox Mediators in Regenerative Dye-Sensitized Solar Cells

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Oxygen uptake by a cobalt(II) complex. An undergraduate experiment

Abstract: Using Co(salen) as a model compound illustrating the uptake of oxygen in hemoglobin.

Cited by 26 publications

References 10 publications

MCNTs@MnO2 Nanocomposite Cathode Integrated with Soluble O2-Carrier Co-salen in Electrolyte for High-Performance Li–Air Batteries

MCNTs@MnO2 Nanocomposite Cathode Integrated with Soluble O2-Carrier Co-salen in Electrolyte for High-Performance Li–Air Batteries

Advanced inorganic chemistry laboratory curricula in Australian universities: investigating the major topics and approaches to learning

Metal Coordination Complexes as Redox Mediators in Regenerative Dye-Sensitized Solar Cells

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MCNTs@MnO₂ Nanocomposite Cathode Integrated with Soluble O₂-Carrier Co-salen in Electrolyte for High-Performance Li–Air Batteries

MCNTs@MnO₂ Nanocomposite Cathode Integrated with Soluble O₂-Carrier Co-salen in Electrolyte for High-Performance Li–Air Batteries