Lee Min Hyung

Abstract The electrocatalytic conversion of CO 2 to value‐added hydrocarbons is receiving significant attention as a promising way to close the broken carbon‐cycle. While most metal catalysts produce C 1 species, such as carbon monoxide and formate, the production of various hydrocarbons and alcohols comprising more than two carbons has been achieved using copper (Cu)‐based catalysts only. Methods for producing specific C 2 reduction outcomes with high selectivity, however, are not available thu

Perfect texture: The roles of surface nanotexturing, TiO2 passivation, and a ruthenium cocatalyst on the photoelectrochemical evolution of hydrogen by using p-InP photocathodes are investigated. Higher current densities and more favorable onset potentials are observed after surface nanotexturing. NHE=normal hydrogen electrode. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are ma

Two different materials, apart from each other in a triboelectric series, are required to fabricate high performance triboelectric generators (TEGs). Thus, it often limits the choices of materials and causes related processing issues for TEGs. To address this issue, we report a simple surface functionalization method that can effectively change the triboelectric charging sequence of the materials, broadening material choices and enhancing the performance of TEGs. Specifically, we functionalized

Triboelectric charging involves frictional contact of two different materials, and their contact electrification usually relies on polarity difference in the triboelectric series. This limits the choices of materials for triboelectric contact pairs, hindering research and development of energy harvest devices utilizing triboelectric effect. A progressive approach to resolve this issue involves modification of chemical structures of materials for effectively engineering their triboelectric proper

Sensors based on 2D rGO/2D MoS₂ van der Waals hybrid composites exhibited high sensitivity, extreme selectivity, fast response/recovery, and good reliability to humidity detection.

This paper reports an all-moldable nanofabrication platform that can generate, from a single master, large-area nanoscale patterns with programmable densities, fill factors, and lattice symmetries. Solvent-assisted nanoscale embossing (SANE) could increase the spacing of patterns up to 100% as well as decrease them down to 50% in a single step by stretching or heating a polymer substrate. Also, SANE could reduce critical feature sizes as small as 45% compared to the master by controlled swelling

Ultrafine particulate matters (PMs) are an imminent threat to the human respiratory system, as their sizes are comparable to and even smaller than human tissues. To cope with this situation, researchers have developed and commercialized various personal dust proof masks. However, because of the relatively thick filter membrane to guarantee filtering efficiency, a huge pressure drop across the active filter layer is inevitable and breathing through it becomes uncomfortable. In this work, we inves

GO content tuning gradually enhanced the HER catalytic performance of the MoS₂/rGO hybrids, decreasing the Tafel slope from 82 to 48 mV per decade owing to an increase of catalytically active areas and an electronic transition of MoS₂.

Abstract The electrocatalytic conversion of CO 2 to value‐added hydrocarbons is receiving significant attention as a promising way to close the broken carbon‐cycle. While most metal catalysts produce C 1 species, such as carbon monoxide and formate, the production of various hydrocarbons and alcohols comprising more than two carbons has been achieved using copper (Cu)‐based catalysts only. Methods for producing specific C 2 reduction outcomes with high selectivity, however, are not available thu

A high-throughput process for nanotexturing of hard and soft surfaces based on the roll-to-roll anodization and etching of low-cost aluminum foils is presented. The process enables the precise control of surface topography, feature size, and shape over large areas thereby presenting a highly versatile platform for fabricating substrates with user-defined, functional performance. Specifically, the optical and surface wetting properties of the foil substrates were systematically characterized and

We report high performance flexible piezoelectric nanogenerators (PENGs) by employing vanadium (V)-doped ZnO nanosheets (NSs) and the polydimethylsiloxane (PDMS) composite structure. The V-doped ZnO NSs were synthesized to overcome the inherently low piezoelectric properties of intrinsic ZnO. Ferroelectric phase transition induced in the V-doped ZnO NSs contributed to significantly improve the performance of the PENGs after the poling process. Consequently, the PENGs exhibited high output voltag

Active, stable electrocatalysts based on non-precious metals for the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) are critical for the development of cost-effective, efficient renewable energy technologies. Here, Fe/Fe 3 C-embedded nitrogen-doped carbon was fabricated via pyrolysis of iron-porphyrin-encapsulated mesoporous metal–organic frameworks [PCN-333 (Fe), where “PCN” stands for “porous coordination network”] at 700 °C. The various characterization techniques confi

Electrochemical energy conversion processes such as water reduction to produce hydrogen and carbon dioxide reduction into valuable carbon products have attracted great attention as alternative green energy technologies to fossil fuels. Nevertheless, the conversion efficiency and long-term stability of these technologies remain very far from the requirements for industrial applications because of the sluggish kinetics of the oxygen evolution reaction (OER). In this study, La-doped NiFe-layered do