Jong‐Sik Kim
경희대학교 Materials Science · 재료과학
김종식 교수의 연구실은 주로 철 산화물 및 인산염을 중심으로 한 나노소재의 표면 화학과 전자구조를 NMR 및 DFT를 융합한 정밀 분석을 통해 연구합니다. 특히, 인산 이온이 토양 미네랄 표면에 어떻게 결합하는지, 그리고 리튬이온 배터리의 핵심 재료인 철 인산염의 전기화학적 거동을 규명하는 데 초점을 맞추고 있습니다. 또한 플라즈마-촉매 상호작용을 통한 C–H 결합 활성화 메커니즘과 나노다공성 탄소 기반 촉매의 산화적 탈황 반응 성능 향상에 관한 연구도 진행 중입니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Phosphate adsorption on the surfaces of the iron oxyhydroxide polymorphs goethite, akaganeite, and lepidocrocite were studied by using 31P static spin-echo mapping NMR experiments to determine how this environmentally-important anion binds to common soil minerals. The large 31P hyperfine shifts confirm the formation of inner-sphere complexes between the phosphate anion and the iron oxyhydroxide surface, the large shifts indicating the presence of Fe3+–O–P covalent bonds. Binding was explored as
Iron phosphates (FePO(4)) are among the most promising candidate materials for advanced Li-ion battery cathodes. This work reports upon a combined nuclear magnetic resonance (NMR) experimental and periodic density functional theory (DFT) computational study of the environments and electronic structures occurring in a range of paramagnetic Fe(III) phosphates comprising FePO(4) (heterosite), monoclinic Li(3)Fe(2)(PO(4))(3) (anti-NASICON A type), rhombohedral Li(3)Fe(2)(PO(4))(3) (NASICON B type),
The elucidation of catalyst surface-plasma interactions is a challenging endeavor and therefore requires thorough and rigorous assessment of the reaction dynamics on the catalyst in the plasma environment. The first step in quantifying and defining catalyst-plasma interactions is a detailed kinetic study that can be used to verify appropriate reaction conditions for comparison and to discover any unexpected behavior of plasma-assisted reactions that might prevent direct comparison. In this paper
Recent shale gas discoveries and advances in plasma chemistry provide the basis to exploit metal surface–plasma interactions to precisely control C–H bond activation on catalytic surfaces, leading to improved reaction efficiencies. Although the exact determination of plasma–catalyst interactions remains a topic of continuing research, this Letter provides evidence that plasma–catalyst interactions exist and can be used to significantly enhance the activation of C–H bonds at temperatures >630 K,
2H and 7Li MAS NMR spectroscopy techniques were applied to study the local surface and bulk environments of iron oxyhydroxide lepidocrocite (gamma-FeOOH). 2H variable-temperature (VT) MAS NMR experiments were performed, showing the presence of short-range, strong antiferromagnetic correlations, even at temperatures above the Néel temperature, T(N), 77 K. The formation of a Li+ inner-sphere complex on the surface of lepidocrocite was confirmed by the observation of a signal with a large 7Li hyper
This work describes a novel method for the preparation of titanium oxide nanoparticles supported on amorphous carbon with nanoporosity (Ti/NC) via the post-synthetic modification of a Zn-based MOF with an amine functionality, IRMOF-3, with titanium isopropoxide followed by its carbothermal pyrolysis. This material exhibited high purity, high surface area (>1000 m(2)/g), and a high dispersion of metal oxide nanoparticles while maintaining a small particle size (~4 nm). The material was shown to b
Although the chemopreventive and antitumorigenic activities of nonsteroidal anti-inflammatory drug (NSAID) against colorectal cancer are well established, the molecular mechanisms responsible for these properties in ovarian cancer have not been elucidated. Therefore, there is an urgent need to develop mechanism-based approaches for the management of ovarian cancer. To this end, the effect of several NSAIDs on ovarian cancer cells was investigated as assessed by the induction of NAG-1/MIC-1/GDF-1
Based on the important role of microRNA (miRNA) biosynthesis genes in carcinogenesis, we hypothesized that polymorphisms in the miRNA biosynthesis genes may modulate susceptibility to lung cancer. To test this hypothesis, we conducted a two-stage study to evaluate the associations between single nucleotide polymorphisms (SNPs) in the miRNA biosynthesis genes and the risk of lung cancer. In stage 1 of the study, 24 SNPs in the 11 miRNA biosynthesis genes (DROSHA, DGCR8, RAN, XPO5, DICER, AGO1, AG
Fe<sub>2</sub>V<sub>4</sub>O<sub>13</sub> outperforms FeVO<sub>4</sub> as an active site for NH<sub>3</sub>-SCR and resists SO<sub>2</sub>/ABS/Na poisons with the inclusion of an Sb promoter.
2H and 7Li MAS NMR spectroscopy have been applied to characterize the surface and bulk hydroxyl groups and Li+ sorption on the iron oxyhydroxide akaganeite (β-FeOOH), a common soil mineral with a large surface area and uptake capacity for toxic cations and anions. The formation of both inner and outer-sphere complexes on the surface of akaganeite was confirmed, the former giving rise to 7Li NMR signals with large 7Li hyperfine shifts. The concentrations of these complexes was determined as a fun
Although substitution of aluminum into iron oxides and oxyhydroxides has been extensively studied, it is difficult to obtain accurate incorporation levels. Assessing the distribution of dopants within these materials has proven especially challenging because bulk analytical techniques cannot typically determine whether dopants are substituted directly into the bulk iron oxide or oxyhydroxide phase or if they form separate, minor phase impurities. These differences have important implications for