Gimyeong Seong 교수

As described herein, the synthesis of highly Cr-substituted CeO2 nanoparticles (Cr-CeO2) for low-temperature bitumen upgrading is demonstrated using a supercritical hydrothermal method including a subcritical region. A continuous flow reactor that can provide a non-equilibrium process was used to improve Cr substitution in the CeO2 lattice. Consequently, a Cr-substitution concentration of 22.7 mol %, which was unobtainable using the equilibrium process (5.1 mol %), was achieved. As the Cr-substi

CeO₂-based nanomaterials have received tremendous attention due to their variety of applications. This paper is focused on the recent advances in facet-controlled CeO₂-based nanomaterials by the hydrothermal method. CeO₂-based nanomaterials with controllable size and exposed facets can be prepared by adjusting the reaction parameters. Moreover, doping and loading metals can improve the oxygen storage capacity (OSC) of CeO₂ and its catalytic activity. V

Highly crystalline cobalt nanoparticles with low surface oxidation were synthesized by the reductive supercritical hydrothermal process in the temperature range from 340 to 420 °C. Under these reaction conditions, hydrogen generated from formic acid decomposition is maximally soluble in water, enabling the effective reduction of cobalt ions and cobalt oxide. The reaction mechanism was investigated by kinetic analysis on the formation of cobalt nanoparticles. This analysis assumed the first order

This review presents a comprehensive and precise summary of the hydrothermal synthesis and morphology control of zinc oxide (ZnO) nanomaterials, the advantages of hydrothermal synthesis, and the wide range of applications. ZnO nanomaterials have garnered significant attention in recent years for their diverse applications across various industries owing to their unique properties and versatility, with practical applications in healthcare, cosmetics, textiles, automotive, and other sectors. Speci

CeO₂ nanoparticles exhibit potential as solid adsorbents for carbon dioxide (CO₂) capture and storage (CCS), offering precise control over various facets and enhancing their efficiency. This study investigated the adsorption and desorption behaviors of two types of CeO₂ nanoparticles: cubic CeO₂ with primarily {001} facets and polyhedral CeO₂ with mainly {111} facets. The results showed that despite polyhedral CeO₂'s lower quantit

In recent years, cerium dioxide (CeO2) has attracted considerable attention owing to its remarkable performance in various applications, including photocatalysis, fuel cells, and catalysis. This study explores the effect of nickel (Ni) doping on the structural, thermal, and chemical properties of CeO2 nanorods, particularly focusing on oxygen vacancy-related phenomena. Utilizing X-ray powder diffraction (XRD), alterations in crystal structure and peak shifts were observed, indicating successful

This paper presents the experimental forced convective heat transfer coefficient (HTC) of nanorods (NRs) zinc oxide-ethylene glycol nanofluids (ZnO-EG NFs) in laminar flow. First, ZnO NRs were synthesized using a hydrothermal method that uses zinc acetate dihydrate [Zn(CH₃COO)₂·2H₂O] as a precursor, sodium hydroxide as a reducing agent, and polyvinylpyrrolidone (PVP) as a surfactant. The hydrothermal reaction was performed at 170 °C for 6 h in a Teflon-lined stai

Research and development in materials science has improved tremendously over the past few decades, resulting in benefits to the quality of life of people worldwide [...].

• Low-temperature methane steam reforming enabled via chemical looping. • {001} facet-exposed CeO 2 nanocubes serve as carbon carriers to enhance hydrogen production. • Hydrogen is selectively produced during methane flow, with carbon removed during steam flow. • Oxygen vacancies govern the overall pathway, driving sustained hydrogen generation. Conventional steam methane reforming (SMR) requires high temperatures (>800 °C) and suffers from carbon deposition, reducing efficiency and deactivating