Synthesis of bare Pt<sub>3</sub>Ni nanorods from PtNi@Ni core–shell nanorods by acid etching: one-step surfactant removal and phase conversion for optimal electrochemical performance toward oxygen reduction reaction

Yoon, Jisun; Park, Jongsik; Jin, Young; Yang, Yoojin; Baik, Hionsuck; Lee, Kwangyeol

doi:10.1039/c6ce00830e

Cited by 19 publications

(13 citation statements)

References 37 publications

(26 reference statements)

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“…The relative intensity of the Ni metal 2p peak decreased, while that of the Ni 2+ 2p peak slightly increased after chemical etching, demonstrating that the dissolution of Ni metal phase in the acid involves the conversion of Ni metal phase to Ni 2+ oxidized state. The N 1s XPS peak (Figure S2d), indicating the existence of oleylamine, was barely observed after the chemical etching, because the chemical etching process also removes the surfactants. − …”

Section: Resultsmentioning

confidence: 99%

Radially Phase Segregated PtCu@PtCuNi Dendrite@Frame Nanocatalyst for the Oxygen Reduction Reaction

et al. 2017

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Pt-based alloy nanoframes have shown great potential as electrocatalysts toward the oxygen reduction reaction (ORR) in fuel cells. However, the intrinsically infirm nanoframes could be severely deformed during extended electro-cyclings, which eventually leads to the loss of the initial catalytic activity. Therefore, the structurally robust nanoframe is a worthy synthetic target. Furthermore, ternary alloy phase electrocatalysts offer more opportunities in optimizing the stability and activity than binary alloy ones. Herein, we report a robust PtCuNi ternary nanoframe, structurally fortified with an inner-lying PtCu dendrite, which shows a highly active and stable catalytic performance toward ORR. Remarkably, the PtCu@PtCuNi catalyst exhibited 11 and 16 times higher mass and specific activities than those of commercial Pt/C.

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Section: Resultsmentioning

confidence: 99%

Radially Phase Segregated PtCu@PtCuNi Dendrite@Frame Nanocatalyst for the Oxygen Reduction Reaction

et al. 2017

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“…Though a large number of noble metals e.g. Pt, Ru, Ir as an electrode has been used for storing the energy to fulfill the energy requirements due to limitations such as high cost and less availability of these metals reduces their use in practical day to day needs [5][6][7][8][9][10][11]. Hence, a number of noble non-metals [12][13][14][15] are presented but their performance is poor as compared to the noble metals.…”

Section: Introductionmentioning

confidence: 99%

A review on MXene for energy storage application: effect of interlayer distance

Garg

Agarwal

2020

Mater. Res. Express

152

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To meet the energy needs batteries and supercapacitors are evolved as a promising candidate from the class of energy storage devices. The growth in the development of new 2D electrode materials brings a new revolution in energy storage devices with a comprehensive investigation. MXene, a new family of 2D metal carbides, nitrides and carbonitrides due to their attractive electrical and electrochemical properties e.g. hydrophilicity, conductivity, surface area, topological structure have gained huge attention. In this review, we discussed different MXene synthesis routes using different etchants e.g. hydrofluoric acid, ammonium hydrazine, lithium fluoride, and hydrochloric acid, etc showing that fluorine formation is compulsory to etch the aluminum layer from its precursor. Due to the advantage of large interlayer spacing between the MXene layers in MXene, the effect of intercalation on the performance of batteries and supercapacitors using MXene as electrodes by various sized cations are reviewed. Different MXene hybrids as supercapacitor electrodes will also be summarized. Lastly, the conclusion and future scope of MXene to be done in various supercapacitor applications are also presented.macropores is very limited [17]. The carbon nanotubes and graphene were also studied in the literature [4]. It is observed from the previous studies that the graphene structure poses a serious limitation on device capacitance as the graphene layers get agglomerated easily and thus the electrode area is not accessible completely by the electrolyte ions [25]. Further, to increase the supercapacitor capacitance Conway et al used ruthenium oxide (RuO 2 ) as electrode material in the device [23]. However, the cost of RuO 2 is very high which opens new doors for other metal oxide materials. The magnesium oxide (MnO 2 ) can be a good alternative to ruthenium oxide because of its low-cost but used very limited in the literature due to low conductivity (10 −4 -10 −5 S cm −1 ) and thus requires extra attention to enhance the conductivity [26].New electrode materials are getting researched day by day by various authors to find a unique solution for energy storage devices. In this context, the main focus is going towards the 2D materials due to their excellent physical and chemical properties as compared to their properties in the bulk [27]. During this investigation, various new members of 2D materials like metal-organic frameworks (MoF) [28,29], polyoxometalates (POM)[30] and black phosphorus (BP) [31] are discovered. The major drawbacks of these 2D electrode materials include poor specific capacitance, less electrical conductivity, structure degradation and limited transport of the ions/electrons. The serious obstacle in many of these electrode materials includes expansion in the volume, less interlayer spacing, less conductivity, and hydrophobic nature. Moreover, the surface oxidation and surface defects limit their scope for energy storage applications [32]. In 2011 Naguib et al [33] showed the potential application of MXene as electro...

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“…Therefore, it is extremely important to design the synthesis of shape‐controlled Pt‐Ni NPs toward their potential use in cathode layers of PEMFCs. The syntheses of Pt‐Ni NPs have explored a variety of metal precursors, [ 17 ] postsynthesis treatment, [ 18 ] and dealloying or etching processes [ 19–24 ] to yield the best electrocatalysts. The ability to tune the morphology by surfactant‐assisted synthesis [ 25 ] has been instrumental in enhancing the mass activity of polyhedral Pt‐Ni NPs.…”

Section: Introductionmentioning

confidence: 99%

Octahedral to Cuboctahedral Shape Transition in 6 nm Pt₃Ni Nanocrystals for Oxygen Reduction Reaction Electrocatalysis

Zysler

Zitoun

2020

Part & Part Syst Charact

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this study), leads to difficulty producing scaled-up catalyst quantities sufficient for a PEMFC test.Extensive efforts have been carried out to obtain control on the shape, exposed facets, [7] and size of Pt-Ni bimetallic nanoparticles (NPs); [8][9][10][11] with different elemental composition, [12] surface composition, [13][14][15] and porosity [16] to enhance the ORR activity and durability with the lowest possible amount of Pt. Therefore, it is extremely important to design the synthesis of shape-controlled Pt-Ni NPs toward their potential use in cathode layers of PEMFCs. The syntheses of Pt-Ni NPs have explored a variety of metal precursors, [17] postsynthesis treatment, [18] and dealloying or etching processes [19][20][21][22][23][24] to yield the best electrocatalysts. The ability to tune the morphology by surfactantassisted synthesis [25] has been instrumental in enhancing the mass activity of polyhedral Pt-Ni NPs. The reaction mechanism of growth [26] and etching [27] has been scarcely reported.Solvothermal synthesis usually generates octahedral NPs with high ORR activity of the {111} facets and yield bimetallic nanoparticles with a Pt skeleton and a Ni-rich core. [28] Pt-Ni cuboctahedra nanocrystals with a high activity toward the same reaction have been reported. Cui et al. [13] have reported very high activities. Recently, a very high specific activity has been reported for a well-defined octahedral particle but the rather large particle size (10-15 nm) impedes the mass activity. [29] In this paper, we investigate the structure-properties relationship of Pt 3 Ni NPs with a particle size of 5-6 nm, which is close to the optimal value for ORR electrocatalysts and the lowest reported to still display shape and preferential crystallographic orientation of the facets. We show how a simple synthetic parameter, the ratio between the solution and the free volume in the reactor, leads to the formation of octahedral or cuboctahedral PtNi nanocrystals. Interestingly, each shape displays a different chemical ordering with Pt or Nirich surface, as evidenced by high-angle annular dark-field (HAADF)-high-resolution transmission electron microscopy (HRTEM) mapping. In the case of cuboctahedral NPs, after a few cyclic voltammograms in acidic medium, the NPs retain their geometry but display a Pt-rich skin which explains their ORR activity.Pt 3 Ni stands as one of the most active electrocatalysts for the oxygen reduction reaction (ORR). The activity varies with the morphology of the nanocrystals with a high activity observed for the octahedral shape where only the high density {111} crystallographic planes are exposed. Herein, the synthesis of 6 nm Pt 3 Ni octahedral nanocrystals with a Pt enriched shell or cuboctahedral nanocrystals with a Ni enriched shell is described. Interestingly, the cuboctahedral nanocrystals display a six-pointed star/skeleton of platinum, which features a very uncommon atomic distribution. In the synthesis, a decrease in the oxygen partial pressure induces the transition from octahedral to cub...

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Synthesis of bare Pt₃Ni nanorods from PtNi@Ni core–shell nanorods by acid etching: one-step surfactant removal and phase conversion for optimal electrochemical performance toward oxygen reduction reaction

Cited by 19 publications

References 37 publications

Radially Phase Segregated PtCu@PtCuNi Dendrite@Frame Nanocatalyst for the Oxygen Reduction Reaction

Radially Phase Segregated PtCu@PtCuNi Dendrite@Frame Nanocatalyst for the Oxygen Reduction Reaction

A review on MXene for energy storage application: effect of interlayer distance

Octahedral to Cuboctahedral Shape Transition in 6 nm Pt₃Ni Nanocrystals for Oxygen Reduction Reaction Electrocatalysis

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Synthesis of bare Pt3Ni nanorods from PtNi@Ni core–shell nanorods by acid etching: one-step surfactant removal and phase conversion for optimal electrochemical performance toward oxygen reduction reaction

Cited by 19 publications

References 37 publications

Radially Phase Segregated PtCu@PtCuNi Dendrite@Frame Nanocatalyst for the Oxygen Reduction Reaction

Radially Phase Segregated PtCu@PtCuNi Dendrite@Frame Nanocatalyst for the Oxygen Reduction Reaction

A review on MXene for energy storage application: effect of interlayer distance

Octahedral to Cuboctahedral Shape Transition in 6 nm Pt3Ni Nanocrystals for Oxygen Reduction Reaction Electrocatalysis

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Synthesis of bare Pt₃Ni nanorods from PtNi@Ni core–shell nanorods by acid etching: one-step surfactant removal and phase conversion for optimal electrochemical performance toward oxygen reduction reaction

Octahedral to Cuboctahedral Shape Transition in 6 nm Pt₃Ni Nanocrystals for Oxygen Reduction Reaction Electrocatalysis