Electrodeposition of Nickel Nanoparticles on

Polypyrrole

Kimberly DickSeptember 20, 2002

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Overview• Previous success with electrodeposition of cubic copper

nanocrystals• Goal: to achieve similar results with nickel – produce

nanocrystals of uniform size, shape, and distribution• FCC structure of nickel: aim to produce single-crystal

cubes• Motivation: catalytic properties of nickel – possible

application in catalysis science

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Cubic Copper Nanocrystals

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Method• Electrodeposition of ~ 100 nm polypyrrole

– Deposit at 0.8 V overpotential– Control thickness by controlling total charge transfer

• Electrodeposition of ~ 1 ML Ni• Solution of 0.01 M NiSO4, 0.01 M NaClO4 (adaptation of

copper deposition)• Deposit at constant potential

– Typically ~ -0.6 V for Cu– Perform cv scan to determine deposition potential for Ni

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Nickel Deposition from cvScan

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New method

• Use recipe obtained from literature (Lachenwiter & Magnussen, 2001)

• 0.01 M NiSO4, 0.01 M H3BO3, 0.0001 M H2SO4• Recipe originally used to deposit layer of nickel on bare

gold electrodes (by cv scan)

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cv Scan by New Method

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Ni on Au by cv Scan

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Ni on Ppy at –1.2 V

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Regular Ni Nanocrystals –1.4V

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Morphology of Ni Growth

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Clustering Nanoparticles

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Ni Nanowires – 1.3V

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Clustered Nanowires

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Rectangular Nanoparticles

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Sensitivity to Potential – 1.5V

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Effect of Polymer Morphology and Thickness

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Further Study

• Effect of potential – examine smaller increments (0.1 V difference)

• Effect of polymer – vary thickness to determine effect• Nickel/electrolyte concentrations• e-beam lithography – controlled deposition