Towards efficient oxygen reduction reaction electrocatalysts through graphene doping

Fernandes, Diana M.; Mathumba, Penny; Fernandes, A.J.S.; Iwuoha, Emmanuel I.; Freire, Cristina

doi:10.1016/j.electacta.2019.06.175

Cited by 31 publications

(19 citation statements)

References 64 publications

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“…The inset in Figure 7 depicts Tafel plots for the investigated objects. The slopes of lines are 50.3 mV/dec and 33.8 mV/dec for the initial GC and rGOA-MS, respectively, which are consistent with the values reported in the literature [ 72 , 73 ]. As can be seen from Figure 5 , the GC electrode coated with rGOA-MS demonstrates somewhat higher oxygen reduction currents than the initial GC.…”

Section: Resultssupporting

confidence: 91%

Reduced Graphene Oxide Aerogel inside Melamine Sponge as an Electrocatalyst for the Oxygen Reduction Reaction

et al. 2021

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A graphene oxide aerogel (GOA) was formed inside a melamine sponge (MS) framework. After reduction with hydrazine at 60 °C, the electrical conductive nitrogen-enriched rGOA-MS composite material with a specific density of 20.1 mg/cm3 was used to fabricate an electrode, which proved to be a promising electrocatalyst for the oxygen reduction reaction. The rGOA-MS composite material was characterized by elemental analysis, scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. It was found that nitrogen in the material is presented by different types with the maximum concentration of pyrrole-like nitrogen. By using Raman scattering it was established that the rGOA component of the material is graphene-like carbon with an average size of the sp2-domains of 5.7 nm. This explains a quite high conductivity of the composite obtained.

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Section: Resultssupporting

confidence: 91%

Reduced Graphene Oxide Aerogel inside Melamine Sponge as an Electrocatalyst for the Oxygen Reduction Reaction

et al. 2021

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“…The ORR process exhibits Tafel slopes of 74, 49 and 110 mV·dec −1 for WS 2 @MWNT, MoS 2 @MWNT and Pt/C, respectively. These results suggest that for the built nanocomposites, the conversion of MOO − (the intermediate surface-adsorbed species) to MOOH (where M is an empty site on the electrocatalyst surface) rules the global reaction rate, while for Pt/C, it is likely the first discharge step or the consumption of the MOOH species that determines the reaction rate [ 57 ].…”

Section: Resultsmentioning

confidence: 99%

Nanocomposites Prepared from Carbon Nanotubes and the Transition Metal Dichalcogenides WS2 and MoS2 via Surfactant-Assisted Dispersions as Electrocatalysts for Oxygen Reactions

et al. 2021

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Fuel cells are emerging devices as clean and renewable energy sources, provided their efficiency is increased. In this work, we prepared nanocomposites based on multiwalled carbon nanotubes (MWNTs) and transition metal dichalcogenides (TMDs), namely WS2 and MoS2, and evaluated their performance as electrocatalysts for the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR), relevant to fuel cells. The one- and two-dimensional (1D and 2D) building blocks were initially exfoliated and non-covalently functionalized by surfactants of opposite charge in aqueous media (tetradecyltrimethylammonium bromide, TTAB, for the nanotubes and sodium cholate, SC, for the dichalcogenides), and thereafter, the three-dimensional (3D) MoS2@MWNT and WS2@MWNT composites were assembled via surfactant-mediated electrostatic interactions. The nanocomposites were characterized by scanning electron microscopy (SEM) and structural differences were found. WS2@MWNT and MoS2@MWNT show moderate ORR performance with potential onsets of 0.71 and 0.73 V vs. RHE respectively, and diffusion-limiting current densities of −1.87 and −2.74 mA·cm−2, respectively. Both materials present, however, better tolerance to methanol crossover when compared to Pt/C and good stability. Regarding OER performance, MoS2@MWNT exhibits promising results, with η10 and jmax of 0.55 V and 17.96 mA·cm−2, respectively. The fabrication method presented here is cost-effective, robust and versatile, opening the doors for the optimization of electrocatalysts’ performance.

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“…[196][197][198][199][200] As witnessed, the doped 2D materials (e.g., graphene, MnO 2 , 2D MOF, MXene, LDHs, TMCs) have been extensively investigated as both the ORR and OER catalysts, while some of them have to be modified to offer bifunctional catalysis. [201][202][203][204][205][206][207][208][209] Implementation of these doped 2D materials enables various promising metal-air batteries to fully exploit the rich surface catalysis. [210][211][212][213] Figure 6f,h, as an example, shows a N-CoSe 2 /3D MXene (Ti 3 C 2 T x ) material used as the cathode of an aqueous Zn-air battery.…”

Section: Chemical Doping and Functionalizationmentioning

confidence: 99%

Engineering 2D Materials: A Viable Pathway for Improved Electrochemical Energy Storage

Lin

Chen

Liu

et al. 2020

Advanced Energy Materials

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Figure 1. a) The Ragone plots showing specific power against specific energy of traditional supercapacitors and electrochemical batteries. The arrows show the trends toward greater specific power for batteries and specific energy for supercapacitors. The time constant represents the charge/discharge rate. LTO: lithium titanium oxide. Reproduced with permission. [4] Copyright 2020, Springer Nature. b) Carrier mobility of some 2D materials. [41-53] c) A schematic diagram showing graphene nanoribbon with armchair and zigzag edges. The-C-OH and-CH terminated zigzag edges have similar band structure, while the-CH 2 , C=O, and C 2 O terminated zigzag edges are all metallic. d) Comparison of the areal capacitance values between graphene plane, armchair, and zigzag edges, with and without considering the SASA. e) A schematic diagram showing the synthesis route of full zigzag graphene nanoribbon. The U-shaped monomer 1 and the monomer 1a were designed for the synthesis. Reproduced with permission. [60] Copyright 2016, Springer Nature. f,g) High-resolution transmission electron microscopy (HRTEM) images of activated graphene sheets with f) wrinkled surface and g) pentagon-heptagon structure. Reproduced with permission.

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Towards efficient oxygen reduction reaction electrocatalysts through graphene doping

Cited by 31 publications

References 64 publications

Reduced Graphene Oxide Aerogel inside Melamine Sponge as an Electrocatalyst for the Oxygen Reduction Reaction

Reduced Graphene Oxide Aerogel inside Melamine Sponge as an Electrocatalyst for the Oxygen Reduction Reaction

Nanocomposites Prepared from Carbon Nanotubes and the Transition Metal Dichalcogenides WS2 and MoS2 via Surfactant-Assisted Dispersions as Electrocatalysts for Oxygen Reactions

Engineering 2D Materials: A Viable Pathway for Improved Electrochemical Energy Storage

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