Shape-controlled synthesis of porous AuPt nanoparticles and their superior electrocatalytic activity for oxygen reduction reaction

Sun, Lixin; Wang, Hongjing; Eid, Kamel; Wang, Liang

doi:10.1080/14686996.2016.1140307

Cited by 22 publications

(7 citation statements)

References 31 publications

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“…Importantly, these results indicate that internal pore size and pore density are independent of slice depth, implying any slice on the NP gives a representation of the pore size and pore density throughout the entire NP. Gaining control over these conditions through variation of electrodeposition parameters, probing the tomographical differences between NPs, and studying their effects on electrocatalysis − constitute our current avenues of investigation.…”

Section: Resultsmentioning

confidence: 99%

Advanced Characterization Techniques for Evaluating Porosity, Nanopore Tortuosity, and Electrical Connectivity at the Single-Nanoparticle Level

Glasscott

Pendergast

Choudhury

et al. 2018

ACS Appl. Nano Mater.

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We demonstrate quantification of porosity, nanopore tortuosity, and electrical connectivity at the singlenanoparticle (NP) level for NPs synthesized by nanodropletmediated electrodeposition. Focused ion beam nanoslice tomography was used to slice NPs with ca. 10 nm slice resolution followed by imaging using scanning electron microscopy (SEM), allowing measurement of these parameters on NPs not amenable to transmission electron microscopy. Slices were reconstructed in three dimensions and revealed pores with an average size of 3 ± 2 nm and relative nanopore tortuosity of 46.8 ± 24.5. We also demonstrate a new technique to evaluate electrical connectivity at the single-NP level by taking advantage of material-selective electrodeposition. The rate of Cu electrodeposition differs significantly on Pt compared to carbon, implying Cu can be selectively electrodeposited onto Pt NPs adsorbed onto a carbon support. Following the Cu electrodeposition step, NP connectivity was determined by the presence of Cu on Pt, as studied by energy-dispersive X-ray spectroscopy and SEM. We demonstrate that NPs synthesized by electrodeposition have >97% connectivity with underlying highly oriented pyrolytic graphite (HOPG) or amorphous carbon electrodes. The same method was employed to study connectivity of citrate-capped Pt NPs (diameter of 70 nm) on HOPG and amorphous graphite adsorbed by drop-casting. Surprisingly, <80% of these NPs had connectivity on HOPG and <40% had connectivity on amorphous carbon. These techniques will find applications in nanomaterials characterization, particularly in the fields of electrocatalysis and energy storage and conversion.

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Section: Resultsmentioning

confidence: 99%

Advanced Characterization Techniques for Evaluating Porosity, Nanopore Tortuosity, and Electrical Connectivity at the Single-Nanoparticle Level

Glasscott

Pendergast

Choudhury

et al. 2018

ACS Appl. Nano Mater.

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“…In our previous study, we successfully synthesized mesoporous Pd films by using cetyltrimethylammonium chloride (CTAC) as pore-directing agent, which participates in the formation of intermediate CTA + /[PdCl 4 ] 2– during the reaction process . For well-constructed mesoporous metallic structures to be achieved, micelles based on different categories of surfactants (e.g., cationic, nonionic, anionic) have been selected for their specific affinities with the target materials. − Until now, only cationic surfactants have been employed to direct the fabrication of mesoporous palladium (Pd), which is more abundant than platinum (Pt) and represents a promising candidate for several applications. − Although mass transport is already facilitated by making the metal mesoporous, it can be further improved by expanding the pore size. The diameter of the obtained mesopores is limited to less than 5 nm due to the small molecular weight of the pore-directing molecules, thereby greatly hindering its practical application.…”

Section: Introductionmentioning

confidence: 99%

Continuous Mesoporous Pd Films by Electrochemical Deposition in Nonionic Micellar Solution

Iqbal

Wood

et al. 2017

Chem. Mater.

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Mesoporous metals that combine catalytic activity and high surface area can provide more opportunities for electrochemical applications. Various synthetic methods, including hard and soft templating, have been developed to prepare mesoporous/nanoporous metals. Micelle assembly, typically involved in soft-templates, is flexible and convenient for such purposes. It is, however, difficult to control, and the ordering is significantly destroyed during the metal deposition process, which is detrimental when it comes to designing precisely mesostructured materials. In the present work, mesoporous Pd films were uniformly electrodeposited using a nonionic surfactant, triblock copolymer poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide), as a pore-directing agent. The interaction between micelles and metal precursors greatly influences the metal growth and determines the final structure. The water-coordinated species interact with the ethylene oxide moiety of the micelles to effectively drive the Pd(II) species toward the working electrode surface. From small-angle neutron scattering data, it is found that spherical P123 micelles, with an average diameter of ∼14 nm, are formed in the electrolyte, and the addition of Pd ions does not significantly modify their structure, which is the essence of the micelle assembly approach. The uniformly sized mesopores are formed over the entire mesoporous Pd film and have an average pore diameter of 10.9 nm. Cross-sectional observation of the film also shows mesopores spanning continuously from the bottom to the top of the film. The crystallinity, crystal phase, and electronic coordination state of the Pd film are also confirmed. Through this study, it is found that the optimized surfactant concentration and applied deposition potential are the key factors to govern the formation of homogeneous and well-distributed pores over the entire film. Interestingly, the as-prepared mesoporous Pd films exhibit superior electrocatalytic activity toward the ethanol oxidation reaction by fully utilizing the accessible active surface area. Our approach combines electrochemistry with colloidal and coordination chemistry and is widely applicable to other promising metals and alloy electrocatalysts.

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“…• The incorporation of carbon nitride into other active materials like MXenes, 238 diamond, 239 metal–organic frameworks (MOFs), 3 functionalized carbon, 240 graphene, 241 porous branched multi-metallic nanocrystals, 242–246 and high-entropy alloys 247 can augment CO oxidation substantially due to impressive conductivity, large surface areas, and desirable properties. Also, using earth-abundant hetero non-metal trace elements ( i.e.…”

Section: Conclusion and Future Perspectivesmentioning

confidence: 99%

Graphitic carbon nitride-based nanostructures as emergent catalysts for carbon monoxide (CO) oxidation

2023

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Shape-controlled synthesis of porous AuPt nanoparticles and their superior electrocatalytic activity for oxygen reduction reaction

Cited by 22 publications

References 31 publications

Advanced Characterization Techniques for Evaluating Porosity, Nanopore Tortuosity, and Electrical Connectivity at the Single-Nanoparticle Level

Advanced Characterization Techniques for Evaluating Porosity, Nanopore Tortuosity, and Electrical Connectivity at the Single-Nanoparticle Level

Continuous Mesoporous Pd Films by Electrochemical Deposition in Nonionic Micellar Solution

Graphitic carbon nitride-based nanostructures as emergent catalysts for carbon monoxide (CO) oxidation

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