One-pot synthesis of a mesoporous NiCo2O4 nanoplatelet and graphene hybrid and its oxygen reduction and evolution activities as an efficient bi-functional electrocatalyst

Lee, Dong Un; Kim, Bae-Jung; Chen, Zhongwei

doi:10.1039/c3ta01402a

Cited by 492 publications

(354 citation statements)

References 51 publications

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“…Specifi cally, the fi tting peak of O 1s A at 529.6 eV is pointed to the oxygen-metal bond, the O 1s B located at 531.1 eV is commonly associated with oxygen from the hydroxyl groups and the O 1s C appeared at 533.5 eV can be assigned to oxygen species in the surface-adsorbed H 2 O molecule. [ 40,43,44 ] Logically, this can explain that the O1s A is the dominating oxygen species existing in the NiCo 2 O 4 nanofl akes. However, the simultaneous presence of O 1s B indicates the NiCo 2 O 4 nanofl akes are hydroxylated arising from either surface hydroxyl groups or substitution of oxygen atoms at the surface by hydroxyl groups.…”

Section: Resultsmentioning

confidence: 96%

Bifunctional Porous NiFe/NiCo₂O₄/Ni Foam Electrodes with Triple Hierarchy and Double Synergies for Efficient Whole Cell Water Splitting

Xiao

et al. 2016

Adv Funct Materials

586

348

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3515wileyonlinelibrary.com OER and HER catalysts based on the earth-abundant fi rst row transition metals (Fe, Co, and Ni, etc.) has received extensive research interest. [9][10][11][12][13] Although signifi cant progress has been achieved, great challenges remain for nonprecious catalysts to achieve activity and stability that are comparable to conventional precious metals. To this end, one promising approach is to develop multimetallic/carbon catalysts by taking advantage of abundant metal-metal and metal-carbon synergistic interactions to enhance the performance of nonprecious catalysts. [14][15][16] The NiFe (oxy)hydroxide-based catalysts are regarded as one of the best performing nonprecious OER electrocatalysts in alkaline solutions, [17][18][19][20][21] which can be synthesized by coupling with carbon nanotube or graphene to achieve better conductivity and synergistic effects via hydrothermal, [ 19,22 ] or electrodeposition onto gold, glassy carbon, and nickel foam, etc., conductive current collector substrates. [ 19,23,24 ] The high OER activities of NiFe catalysts are generally attributed to a strong synergistic effect upon the incorporation of Fe, even in trace amount, into NiOOH, although the complete mechanisms and structural characteristics are not yet fully understood. [ 19,23 ] NiFe catalysts also have been reported for HER in alkaline media, [ 25 ] although the synergistic effect for HER is not as signifi cant as that for OER, and the reported activity for HER is relatively low compared to state-of-the-art nonprecious HER catalysts. Nevertheless, using the same catalyst as both the anode and cathode in an electrolysis device is very attractive, which could not only signifi cantly improve the integration and simplifi cation of the water splitting system, but also provide the feasibility of industrial application of water splitting technology.Besides having an effi cient catalyst, rational design of catalyst structure is known to be crucial for improving the electrode performance. In pursuit of creating large surface area and high active site density, various attempts have been devoted to developing 3D nanostructured catalyst materials, [26][27][28] such as mesoporous NiFe nanosheets, [ 24 ] NiCo 2 O 4 nanosheets/halloysite nanotubes, [ 26 ] hierarchically structured carbon microfi bre, [ 29 ] and multilayered TiO 2 nanowire arrays. [ 30 ] Moreover, smart design of a catalyst with macroscopic structure onto conductive porous support (e.g., nickel foam) could afford Bifunctional Porous NiFe/NiCo 2 O 4 /Ni Foam Electrodes with Triple Hierarchy and Double Synergies for Effi cient Whole Cell Water SplittingChanglong Xiao , Yibing Li , Xunyu Lu , and Chuan Zhao * A 3D hierarchical porous catalyst architecture based on earth abundant metals Ni, Fe, and Co has been fabricated through a facile hydrothermal and electrodeposition method for effi cient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). The electrode is comprised of three levels of porous structures including the bottom su...

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Section: Resultsmentioning

confidence: 96%

Bifunctional Porous NiFe/NiCo₂O₄/Ni Foam Electrodes with Triple Hierarchy and Double Synergies for Efficient Whole Cell Water Splitting

Xiao

et al. 2016

Adv Funct Materials

586

348

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“…[ 56,73,105,129 ] Chen and co-workers reported that a hybrid material of mesoporous NiCo 2 O 4 nanoplatelets and graphene sheets (NiCo 2 O 4 -G) served as an excellent bifunctional catalyst for both ORR and OER. [ 105 ] The NiCo 2 O 4 -G exhibits well-dispersed mesopores within the nanoplates with a large specifi c surface area of 77 m 2 g −1 and an average pore diameter of 11.8 nm. The ORR polarization investigation (Figure 8 f) demonstrates the considerable improvement of NiCO 2 O 4 -G's onset potential and stable current density compared to that of Co 2 O 4 -G, although it is still not comparable with that of commercial Pt/C.…”

Section: Electrochemical Catalysis: Oxygen Reduction and Oxygen Oxidamentioning

confidence: 99%

Nickel Cobaltite Nanostructures for Photoelectric and Catalytic Applications

Liu

et al. 2015

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Bimetallic oxide nickel cobaltite (NiCo2 O4 ) shows extensive potential for innovative photoelectronic and energetic materials owing to their distinctive physical and chemical properties. In this review, representative fabrications and applications of NiCo2 O4 nanostructures are outlined for photoelectronic conversion, catalysis, and energy storage, aiming to promote the development of NiCo2 O4 nanomaterials in these fields through an analysis and comparison of their diverse nanostructures. Firstly, a brief introduction of the spinel structures, properties, and morphologies of NiCo2 O4 nanomaterials are presented. Then, the advanced progress of NiCo2 O4 nanomaterials for both photoelectronic conversion and energy fields is summarized including such examples as solar cells, electrocatalysis, and lithium ion batteries. Finally, further prospects and promising developments of NiCo2 O4 nanomaterials in these significant fields are proposed.

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“…Three recent papers from our group [16][17][18] report oxygen reduction at GDE based on NiCo 2 O 4 catalyst without graphitic carbon. A number of papers have also reported the behavior of nanostructured Co 3 O 4 and NiCo 2 O 4 for oxygen reduction 12,13,[19][20][21][22][23][24][25][26][27][28][29][30][31][32] but the assessment of these data is often hampered by the absence of data at 'standard' surfaces, such as Pt, graphitic carbon, or the uncoated glassy carbon surface, for comparison. The inclusion of such standard surfaces enables accurate comparison of the limiting currents and onset potentials * Electrochemical Society Fellow.…”

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confidence: 99%

Voltammetric Studies of the Mechanism of the Oxygen Reduction in Alkaline Media at the Spinels Co₃O₄and NiCo₂O₄

Sönmez

Thompson

Price

et al. 2016

J. Electrochem. Soc.

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The mechanism of O 2 reduction at the spinels, Co 3 O 4 and NiCo 2 O 4 , in KOH electrolyte is probed using voltammetry at rotating disc and rotating ring-disc electrodes by examination of the rotation rate dependent limiting currents. The analysis shows that the products and mechanisms at the two spinels are quite different. At the cobalt spinel, a substantial amount of the 2e − reduction product, H 2 O 2 , is formed while at NiCo 2 O 4 the 4e − reduction strongly predominates. In terms of both the overpotential for reduction and its limiting current density, the mixed spinel is a substantially better electrocatalyst. It is proposed that the differences arise from an enhanced rate of O-O bond cleavage early in the reduction process at NiCo 2 O 4 .

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One-pot synthesis of a mesoporous NiCo2O4 nanoplatelet and graphene hybrid and its oxygen reduction and evolution activities as an efficient bi-functional electrocatalyst

Cited by 492 publications

References 51 publications

Bifunctional Porous NiFe/NiCo₂O₄/Ni Foam Electrodes with Triple Hierarchy and Double Synergies for Efficient Whole Cell Water Splitting

Bifunctional Porous NiFe/NiCo₂O₄/Ni Foam Electrodes with Triple Hierarchy and Double Synergies for Efficient Whole Cell Water Splitting

Nickel Cobaltite Nanostructures for Photoelectric and Catalytic Applications

Voltammetric Studies of the Mechanism of the Oxygen Reduction in Alkaline Media at the Spinels Co₃O₄and NiCo₂O₄

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One-pot synthesis of a mesoporous NiCo2O4 nanoplatelet and graphene hybrid and its oxygen reduction and evolution activities as an efficient bi-functional electrocatalyst

Cited by 492 publications

References 51 publications

Bifunctional Porous NiFe/NiCo2O4/Ni Foam Electrodes with Triple Hierarchy and Double Synergies for Efficient Whole Cell Water Splitting

Bifunctional Porous NiFe/NiCo2O4/Ni Foam Electrodes with Triple Hierarchy and Double Synergies for Efficient Whole Cell Water Splitting

Nickel Cobaltite Nanostructures for Photoelectric and Catalytic Applications

Voltammetric Studies of the Mechanism of the Oxygen Reduction in Alkaline Media at the Spinels Co3O4and NiCo2O4

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Bifunctional Porous NiFe/NiCo₂O₄/Ni Foam Electrodes with Triple Hierarchy and Double Synergies for Efficient Whole Cell Water Splitting

Bifunctional Porous NiFe/NiCo₂O₄/Ni Foam Electrodes with Triple Hierarchy and Double Synergies for Efficient Whole Cell Water Splitting

Voltammetric Studies of the Mechanism of the Oxygen Reduction in Alkaline Media at the Spinels Co₃O₄and NiCo₂O₄