김명준 교수

The activity of electrocatalysts can be improved by modifying their electronic structures and surface morphologies. In electrochemical reactions with gas evolution, the performance of an electrocatalyst is also affected by how easily gas bubbles depart from an electrocatalyst surface. However, it is difficult to quantitatively estimate the improvement in the performance that can be achieved by promoting the departure of gas bubbles from the electrocatalyst surface. This study investigated the ef

Shape-control is used to tune the properties of metal nanostructures in applications ranging from catalysts to touch screens, but the origins of anisotropic growth of metal nanocrystals in solution are unknown. We show single-crystal electrochemistry can test hypotheses for why nanostructures form and predict conditions for anisotropic growth by quantifying the degree to which different species cause facet-selective metal deposition. Electrochemical measurements show disruption of alkylamine mon

The synthesis of metal nanostructures usually requires a capping agent that is generally thought to cause anisotropic growth by blocking the addition of atoms to specific crystal facets. This work uses a series of electrochemical measurements with a quartz crystal microbalance and single-crystal electrodes to elucidate the facet-selective chemistry occurring in the synthesis of Cu nanowires. Contrary to prevailing hypotheses, ethylenediamine, a so-called capping agent in the synthesis of Cu nano

This article shows how the chain length of alkylamine capping agents and the corresponding stability of their self-assembled monolayers on a Cu surface determines the growth rate, yield, and dimensions of Cu nanowires produced in a solution-phase synthesis. Of the 10 linear alkylamines that were tested, only those with 12 or more carbon atoms induced growth of nanowires. The length, yield, and growth rate of nanowires were larger for shorter alkylamines. As the Cu nanowire growth rates were up t

A method is introduced for Cu bottom-up filling at trenches with dimensions similar to those of through silicon via in the presence of three organic additives. The electrodeposition is galvanostatically conducted, and the potential-time curves during the gap-filling and the evolution of deposition profiles according to the deposition time are investigated to clarify the mechanism of the Cu bottom-up filling. The role of each organic additive is examined by electrochemical analyses and the gap-fi

Flow-through electrodes such as carbon paper are used in redox flow batteries, water purification, and electroorganic syntheses. This work examines the extent to which reducing the size of the fibers to the nanoscale in a flow-through electrode can increase the productivity of electrochemical processes. A Cu nanowire felt, made from nanowires 45 times smaller than the 10 μm wide fibers in carbon paper, can achieve a productivity 278 times higher than carbon paper for mass-transport-limited reduc

Abstract More active electrocatalysts for H 2 and O 2 evolution reactions, efficient membranes, and robust porous transport layers (PTL) are required for designing advanced proton exchange membrane water electrolysis (PEMWE) systems. An N‐doped carbon matrix is introduced in this study to surpass the existing Ti PTLs. One‐step pyrolysis results in the carbonization of polyaniline films to the N‐doped carbon matrix, simultaneous formation of desiccation cracks and Ir x Ru y nanoparticles, and par

Control over the shape of a metal nanostructure grants control over its properties, but the processes that cause solution-phase anisotropic growth of metal nanostructures are not fully understood. This article shows why the addition of a small amount (75–100 μM) of iodide ions to a Cu nanowire synthesis results in the formation of Cu microplates. Microplates are 100 nm thick and micronwide crystals that are thought to grow through atomic addition to {100} facets on their sides instead of the {11

Through silicon via (TSV) technology has been researched for 3-dimensional packaging of electronic devices, and Cu electrodeposition has been used for TSV filling. The organic additives are one of the most important factors in Cu electrodeposition affecting Cu gap-filling, and the leveler usually plays a decisive role. In this research, iodide ion (I−) is adopted instead of organic leveler for Cu bottom-up filling. The behaviors of I− are investigated by various types of electrochemical analyses

A leveler is one of the key additives for the defect-free filling of Through Silicon Via. The convection dependent behavior of a leveler is required to achieve successful gap-filling of Cu. Levelers occasionally contain charged functional groups and the counter anions. The charged functional groups obviously determine the characteristics of the leveler, and counter anions also influence the electrochemical behavior and Cu gap-filling. In this study, we synthesize levelers that have two quaternar