title: Plasmonic imaging of electrochemical oxidation of single nanoparticles.
abstract: Measuring electrochemical activities of nanomaterials is critical for creating novel catalysts, for developing ultrasensitive sensors, and for understanding fundamental nanoelectrochemistry. However, traditional electrochemical methods measure a large number of nanoparticles, which wash out the properties of individual nanoparticles. We report here a study of transient electrochemical oxidation of single Ag nanoparticles during collision with an electrode and voltammetry of single nanoparticles immobilized on the electrode using a plasmonic-based electrochemical current microscopy. This technique images both electrochemical reaction and size of the same individual nanoparticle, enabling quantitative examination of size-dependent electrochemical activities at single nanoparticle level. The imaging capability further allows detection of the reaction kinetics of each individual nanoparticle and analysis of the average behaviors of multiple nanoparticles. The average kinetics and size dependence can be accurately described by the Tafel equation, but there is a large variability between different nanoparticles, which underscores the importance of single nanoparticle analysis.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, China.
authors.forename: Yimin
authors.initials: Y
authors.lastname: Fang
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Xiang
authors.initials: X
authors.lastname: Wo
authors.forename: Yashuang
authors.initials: Y
authors.lastname: Luo
authors.forename: Shaowei
authors.initials: S
authors.lastname: Yin
authors.forename: Yixian
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Shan
authors.forename: Nongjian
authors.initials: N
authors.lastname: Tao
mesh_terms: D055664:Electrochemical Techniques; D004566:Electrodes; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D012834:Silver / Q000737:chemistry*
chemical_list: D012834:Silver