Effects of 3D structure on electrochemical oxygen reduction characteristics of Pt-nanoparticle-supported carbon nanowalls

Imai, Shun; Naito, Kenichi; Kondo, Hiroki; Cho, Hyung Jun; Ishikawa, Kenji; Tsutsumi, Takayoshi; Sekine, Makoto; Hiramatsu, Mineo; Hori, Masaru

doi:10.1088/1361-6463/aaf8e0

Cited by 6 publications

(3 citation statements)

References 30 publications

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“…CNWs were deposited on silicon (Si) substrates using radical injection-plasma enhanced chemical vaper deposition (RI-PECVD) equipment. 10,11,15,16,[26][27][28][29] The substrates used a low-resistivity (⩽0.1 Ω cm) n-type Si (100) wafer. The equipment used a tandem structure with a surface wave plasma (SWP) and a very high frequency (VHF) capacitively coupled plasma (CCP) source connected by a showerhead type CCP electrode.…”

Section: Experimental Methodsmentioning

confidence: 99%

Biocompatibility of conformal silicon carbide on carbon nanowall scaffolds

Ono

Koide

Ishikawa

et al. 2022

Jpn. J. Appl. Phys.

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Silicon carbide (SiC) was coated onto carbon nanowall (CNW) scaffolds using chemical vapor deposition with a vinylsilane precursor at 700°C to investigate the effects of the wall edge width, wall-to-wall distance, and surface morphology. The wall edge width ranged from 10 nm to those filling the wall-to-wall space without destroying the CNW morphology. When SiC-coated CNWs (SiC/CNWs) were used as scaffolds for cell culture, cell viability increased until the edge area ratio reached 40%. In over 40% of edge area ratio, cell viability was saturate and comparable to flat surface such as SiC film on the Si substrate (SiC/Si), and control sample made by polystyrene. Calcification was suppressed in the CNWs, SiC/CNWs, and SiC/Si scaffolds compared to polystyrene. Thus, we found that the SiC coated CNW scaffolds could suppress calcification and promote cell proliferation.

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Section: Experimental Methodsmentioning

confidence: 99%

Biocompatibility of conformal silicon carbide on carbon nanowall scaffolds

Ono

Koide

Ishikawa

et al. 2022

Jpn. J. Appl. Phys.

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“…Tuning and optimizing the morphology and structure of PtM is an important strategy to further improve the performance [20][21][22][23][24]. In recent years, PtNi nanostructures with different morphologies have been reported, such as nanopolyhedrons [19,24,25], nanotubes [7,26], nanoframes [8,27], nanoparticles [28][29][30], and so on. Compared with other nanostructures, multi-branched nanostructures (MBNs) can effectively increase the contact area between catalysts and electrolyte to promote the smooth and rapid reaction [5,31].…”

Section: Introductionmentioning

confidence: 99%

PtNi multi-branched nanostructures as efficient bifunctional electrocatalysts for fuel cell

Zhao¹,

Qian²,

Bai³

et al. 2022

J. Phys. D: Appl. Phys.

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Fuel cells are highly efficient conversion devices to alleviate energy crisis and environmental pollution, but still encounter technical challenges to further improve catalytic efficiency of Pt-based electrocatalysts. In this work, PtNi multi-branched nanostructures (PtNi MBNs) were successfully prepared by a simple and economical one-step solvothermal method. The average diameter of the branches is about 9 nm, with numerous atom steps and Pt-rich surface. The prepared electrocatalyst shows excellent bifunctionality in acidic electrolytes, catalyzing both oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). The half-wave potential of 0.966 V for ORR is much higher than that of commercial Pt/C (0.931 V), and only decreases 14 mV after 8,000 cycles. For MOR, the specific activity of PtNi MBNs is 18.1 A m-2 Pt, better than that of commercial Pt/C (7.8 A m-2 Pt), indicating an optimal intrinsic activity. The remarkable bifunctionality of PtNi MBNs is attributed to the exposed electrochemical surface area, abundant atomic steps, and Pt-rich surface provided by the unique multi-branched nanostructure. This facile preparation technique offers a promising application for designing high-performance electrocatalyst for acid direct methanol fuel cell in the future.

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“…In the fuel cell research field, CNWs have been exploited mainly as a catalyst support, replacing the classic carbon black which is easily oxidized, forming CO 2 at the beginning and the end of the fuel cell cycles. This causes the Pt catalyst to detach and agglomerate, which, eventually, leads to performance degradation [27][28][29]. In this context, our approach is to design a method to employ CNWs, with specific MPL-tailored properties, in PEMFCs, a route not yet addressed in the literature.…”

Section: Introductionmentioning

confidence: 99%

Carbon-Nanowall Microporous Layers for Proton Exchange Membrane Fuel Cell

et al. 2022

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The cathode microporous layer (MPL), as one of the key components of the proton exchange membrane fuel cell (PEM-FC), requires specialized carbon materials to ensure the two-phase flow and interfacial effects. In this respect, we designed a novel MPL based on highly hydrophobic carbon nanowalls (CNW). Employing plasma-assisted chemical vapor deposition techniques directly on carbon paper, we produced high-quality microporous layers at a competitive yield-to-cost ratio with distinctive MPL properties: high porosity, good stability, considerable durability, high hydrophobicity, and substantial conductivity. The specific morphological and structural properties were determined by scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. Thermo-gravimetric analysis was employed to study the nanostructures’ thermal stability and contact angle measurements were performed on the CNW substrate to study the hydrophobic character. Platinum ink, serving as a fuel cell catalyst, was sprayed directly onto the MPLs and incorporated in the FC assembly by hot-pressing against a polymeric membrane to form the membrane-electrode assembly and gas diffusion layers. Single-fuel-cell testing, at moderate temperature and humidity, revealed improved power performance comparable to industrial quality membrane assemblies (500 mW cm−2 mg−1 of cathodic Pt load at 80 °C and 80% RH), with elevated working potential (0.99 V) and impeccable fuel crossover for a low-cost system.

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Effects of 3D structure on electrochemical oxygen reduction characteristics of Pt-nanoparticle-supported carbon nanowalls

Cited by 6 publications

References 30 publications

Biocompatibility of conformal silicon carbide on carbon nanowall scaffolds

Biocompatibility of conformal silicon carbide on carbon nanowall scaffolds

PtNi multi-branched nanostructures as efficient bifunctional electrocatalysts for fuel cell

Carbon-Nanowall Microporous Layers for Proton Exchange Membrane Fuel Cell

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