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A selective blocking method to control the overgrowth of Pt on Au nanorods.

Fennell J, He D, Tanyi AM, Logsdail AJ, Johnston RL, Li ZY, Horswell SL - J. Am. Chem. Soc. (2013)

Bottom Line: A method for the preparation of smooth deposits of Pt on Au nanorods is described, involving sequential deposition steps with selective blocking of surface sites that reduces Pt-on-Pt deposition.The Au-Pt nanorods prepared by this method have higher long-term stability than those prepared by standard Pt deposition.Electrochemical data show that the resulting structure has more extended regions of Pt surface and enhanced activity toward the carbon monoxide oxidation and oxygen reduction reactions.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.

ABSTRACT
A method for the preparation of smooth deposits of Pt on Au nanorods is described, involving sequential deposition steps with selective blocking of surface sites that reduces Pt-on-Pt deposition. The Au-Pt nanorods prepared by this method have higher long-term stability than those prepared by standard Pt deposition. Electrochemical data show that the resulting structure has more extended regions of Pt surface and enhanced activity toward the carbon monoxide oxidation and oxygen reduction reactions.

No MeSH data available.


Related in: MedlinePlus

CO stripping voltammograms for the carbon-supportedcatalysts in0.05 M H2SO4 electrolyte. The scan rate was0.05 V s–1, and the current density is referredto the electrochemically active surface area (see Table 2).
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fig6: CO stripping voltammograms for the carbon-supportedcatalysts in0.05 M H2SO4 electrolyte. The scan rate was0.05 V s–1, and the current density is referredto the electrochemically active surface area (see Table 2).

Mentions: CVs comparing the oxidationof adsorbed CO on the three Au–Ptsamples are presented in Figure 6. The CO wasadsorbed at 0.055 V and displaced from solution with Ar before theCVs were recorded. As expected, each CV shows an absence of featuresrelating to hydrogen desorption (CO adsorption blocks hydrogen adsorptionon the surface), and a new current peak on the anodic scan is present,which corresponds to the oxidative desorption of CO. Interestingly,the onset potentials of CO oxidation are similar for the three samples.However, the breadth of the peak decreases as the Pt surface areaincreases. The nanoparticles with the lowest Pt coverage exhibit thelowest activity, with a broad wave followed by another wave at morepositive potentials. The nanoparticles prepared by the selective blockingmethod produce CVs with a sharp peak centered at more negative potentials,reminiscent of similar measurements on polycrystalline Pt,35 and with higher overall charge than for CVsof the other samples. The sharpness of the peak, along with the CVsof the clean NR surfaces, indicates that the selective blocking methodyields NRs with more extended regions of Pt surface. The higher activityof the particles prepared by selective blocking could also be relatedto the larger number of {110}-type sites observed in the CV data.33,36,37


A selective blocking method to control the overgrowth of Pt on Au nanorods.

Fennell J, He D, Tanyi AM, Logsdail AJ, Johnston RL, Li ZY, Horswell SL - J. Am. Chem. Soc. (2013)

CO stripping voltammograms for the carbon-supportedcatalysts in0.05 M H2SO4 electrolyte. The scan rate was0.05 V s–1, and the current density is referredto the electrochemically active surface area (see Table 2).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3842091&req=5

fig6: CO stripping voltammograms for the carbon-supportedcatalysts in0.05 M H2SO4 electrolyte. The scan rate was0.05 V s–1, and the current density is referredto the electrochemically active surface area (see Table 2).
Mentions: CVs comparing the oxidationof adsorbed CO on the three Au–Ptsamples are presented in Figure 6. The CO wasadsorbed at 0.055 V and displaced from solution with Ar before theCVs were recorded. As expected, each CV shows an absence of featuresrelating to hydrogen desorption (CO adsorption blocks hydrogen adsorptionon the surface), and a new current peak on the anodic scan is present,which corresponds to the oxidative desorption of CO. Interestingly,the onset potentials of CO oxidation are similar for the three samples.However, the breadth of the peak decreases as the Pt surface areaincreases. The nanoparticles with the lowest Pt coverage exhibit thelowest activity, with a broad wave followed by another wave at morepositive potentials. The nanoparticles prepared by the selective blockingmethod produce CVs with a sharp peak centered at more negative potentials,reminiscent of similar measurements on polycrystalline Pt,35 and with higher overall charge than for CVsof the other samples. The sharpness of the peak, along with the CVsof the clean NR surfaces, indicates that the selective blocking methodyields NRs with more extended regions of Pt surface. The higher activityof the particles prepared by selective blocking could also be relatedto the larger number of {110}-type sites observed in the CV data.33,36,37

Bottom Line: A method for the preparation of smooth deposits of Pt on Au nanorods is described, involving sequential deposition steps with selective blocking of surface sites that reduces Pt-on-Pt deposition.The Au-Pt nanorods prepared by this method have higher long-term stability than those prepared by standard Pt deposition.Electrochemical data show that the resulting structure has more extended regions of Pt surface and enhanced activity toward the carbon monoxide oxidation and oxygen reduction reactions.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.

ABSTRACT
A method for the preparation of smooth deposits of Pt on Au nanorods is described, involving sequential deposition steps with selective blocking of surface sites that reduces Pt-on-Pt deposition. The Au-Pt nanorods prepared by this method have higher long-term stability than those prepared by standard Pt deposition. Electrochemical data show that the resulting structure has more extended regions of Pt surface and enhanced activity toward the carbon monoxide oxidation and oxygen reduction reactions.

No MeSH data available.


Related in: MedlinePlus