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

Abstract

The properties of nanoparticles (NPs) are determined by their size and geometric structures. A reliable determination of NP dimension is critical for understanding their physical and chemical properties, but sizing ultrasmall particles on the order of nanometer (nm) scale in the solution is still challenging. Here, we report the size measurement of PtNP at nanometer resolution by in situ scanning electrochemical microscopy (SECM), performed with the electrochemical generation and removal of H bubble at a reasonably small distance between tip and substrate electrodes in 200 or 500 mM HClO solution. A series of different PtNPs or nanoclusters were electrodeposited and in situ measured in the solution, proving the concept of sizing ultrasmall particles using tip generation/substrate collection mode of SECM. This technique could be also used for investigations of other supported ultrasmall metal nanocluster systems.

The Nucleation Rate of Single O2 Nanobubbles at Pt Nanoelectrodes

“… 1 − 3 However, the technology used to visualize such surface nanobubbles has been very recently developed. 2 , 4 − 6 The biggest concern that surface nanobubbles cause is their generation in chemical reactions, such as electrolysis 7 and catalysis. 8 Nanobubbles nucleating on top of reacting surfaces or electrodes influence the efficiency of chemical reactions since they partially block the reactive surface and consequently impede the reaction of interest.…”

Single-entity electrochemistry at confined sensing interfaces

“…Often this is done by coupling extremely small background double-layer capacitance values with near-instantaneous steady-state concentration profiles to offer the spatiotemporal resolution necessary to probe electron transfer kinetics in the nanosecond regime [180][181][182]. In recent years, the employment of nanoelectrodes in electrochemical microscopy techniques has become increasingly important to study a wide variety of different reactions [183][184][185], and to elucidate the localized structure-activity in a wide range of electrochemically active nanomaterials (e.g., nanotubes, graphite and graphene, nanoparticles, and materials for energy storage) [185,186]. These precision measurements pave a new way to explore mechanisms of complex chemical process, expanding analytical applications for electrochemistry.…”

Recent progress in gas nanobubble electrochemistry

“…(fluorescence microscopy) [76] 、暗场显微镜(dark field microscopy) [77~79] 、表面等离激元共振显微镜(surface plasmon resonance microscopy) [80,81] 、电致化学发光显 微镜(electrochemiluminescence microscopy) [82] 等一些 先进光学成像手段被广泛用于单个纳米粒子微观化学 过程研究, 特别是电化学过程(例如Pt纳米粒子电催化 析氢 [80] 、Ag纳米粒子电化学氧化溶解 [83] 、Au或Ag纳 米粒子的电沉积 [77,79] [72] (网络版彩图) Figure 4 Scheme for tip generation-substrate collection mode SECM for the removal of gas nanobubbles [72] (color online).…”