Ungyu Paik 교수

Prussian blue analogue (PBA)-derived carbon coated porous nickel phosphides nanoplates exhibit enhanced electrocatalytic activity for oxygen evolution reaction.

Nickel and cobalt incorporated MoS₂ nanoboxes are synthesized via the reaction between Ni-Co Prussian blue analogue nanocubes and ammonium thiomolybdate. Due to the structural and compositional advantages, these well-defined nanoboxes manifest enhanced electrochemical activity as an electrocatalyst for hydrogen evolution reaction.

Proton-exchange-membrane water electrolysis (PEMWE) requires an efficient and durable bifunctional electrocatalyst for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, Ir-based electrocatalyst is designed using the high entropy alloy (HEA) platform of ZnNiCoIrX with two elements (X: Fe and Mn). A facile dealloying in the vacuum system enables the construction of a nanoporous structure with high crystallinity using Zn as a sacrificial element. Especially, Mn inco

Abstract Borophosphate materials are promising electrocatalysts for water splitting. Their structural flexibility enable self‐adjusting of electronic structure depending on potential. The rich chemistry of borophosphate provides a huge engineering space to tune composition and structure. Herein, amorphized LiNiFe borophosphate (a‐LNFBPO) for an efficient and durable oxygen evolution reaction (OER) is first reported. Facile adsorption of oxygen intermediates on the vacancies generated by spontane

Germanium holds great potential as an anode material for lithium ion batteries due to its large theoretical energy density and excellent intrinsic properties related to its kinetics associated with lithium and electrons. However, the problem related to the tremendous volume change of Ge during cycling is the dominant obstacle for its practical use. The previous research has focused on the improvement in mechanics associated with lithium without consideration of the kinetics. In this study, we de

Abstract The development of cost effective and high‐performance electrocatalyst is challenging but essential for realizing industrial hydrogen production by electolyzer. Electrocatalysts for water splitting must have active catalytic performance as well as high stability in strong alkaline or acidic media to be used in commercial elecrolyzer. Transition metal based electrocatalysts are considered as highly promising candidates due to their excellent oxygen evolution reaction (OER) and hydrogen e

The interaction of dispersant and binder on the surface of particles was studied to identify the effect of these additives on aqueous ceramic powder processing. Poly(methacrylic acid) (PMAA) and poly(vinyl alcohol) (PVA) were used as the dispersant and binder, respectively. The adsorption isotherms of the organic additives on silicon nitride were determined. The adsorption of PMAA was differentiated from PVA in the mixed additive system via ultraviolet spectroscopy. The electrokinetic behavior o

We report on findings that the particle surface charge is influenced by solids concentration in aqueous suspensions of BaTiO 3 . Three decades in solids concentration were analyzed by combining results from two different electrokinetic methods. Combined results demonstrate a systematic acidic shift in the isoelectric pH with decreasing solids concentration. The shift is attributed to the development of a Ba‐depleted, TiO 2 ‐rich surface layer. Using kinetic arguments, it is shown that the thickn

Sn-doped LiTi₂(PO₄)₃/C composite nanofibers are synthesized by a facile electrospinning process.

Surface polarity and shape-controlled ZnO nanostructures are synthesized on GaN thin films using metalorganic vapor phase epitaxy (MOVPE). By adjusting the growth parameters from Zn-rich at low temperature to O-rich at high temperature, morphology of ZnO nanostructures was tuned from nonpolar, smooth-surfaced ZnO nanorod nanowall networks to O-polar, stacked pyramid-structured ZnO nanorods.