Electrochemical Size Measurement and Characterization of Electrodeposited Platinum Nanoparticles at Nanometer Resolution with Scanning Electrochemical Microscopy

Ma, Wei [Center
for Electrochemistry, Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States]; Hu, Keke [Department
of Chemistry and Biochemistry, Queens College, City University of New York, Flushing, New York 11367, United States]; Chen, QianJin [Center
for Electrochemistry, Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States]; Zhou, Min [Center
for Electrochemistry, Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States]; Mirkin, Michael V. [Department
of Chemistry and Biochemistry, Queens College, City University of New York, Flushing, New York 11367, United States]; Bard, Allen J. [Center
for Electrochemistry, Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States] (ORCID:0000000285170230)

doi:10.1021/acs.nanolett.7b01437

Well-ordered nanoparticle arrays are attractive platforms for a variety of analytical applications, but the fabrication of such arrays is generally challenging. Here, it is demonstrated that scanning electrochemical cell microscopy (SECCM) can be used as a powerful, instantly reconfigurable tool for the fabrication of ordered nanoparticle arrays. Using SECCM, Ag nanoparticle arrays were straightforwardly fabricated via electrodeposition at the interface between a substrate electrode and an electrolyte-filled pipet. By dynamically monitoring the currents flowing in an SECCM cell, individual nucleation and growth events could be detected and controlled to yield individual nanoparticles of controlled size. Characterization of the resulting arrays demonstrate that this SECCM-based approach enables spatial control of nanoparticle location comparable with the terminal diameter of the pipet employed and straightforward control over the volume of material deposited at each site within an array. These results provide further evidence for the utility of probe-based electrochemical techniques such as SECCM as tools for surface modification in addition to analysis.

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