Chi Won Ahn
KAIST · Engineering
Chi Won Ahn 교수의 연구실은 2차원 물질, 특히 MXene를 중심으로 한 나노소재의 합성, 안정화 및 응용을 연구하고 있습니다. 산화에 의한 열화 문제를 해결하기 위한 안정성 향상 전략과, 에너지 저장, 전자소자, 생체의학 센서 등 다양한 분야에서의 응용 기술 개발에 주력하고 있습니다. 특히, MXene 기반 전기 히터, 리튬-황 배터리의 전극 및 분리막, 초민감도 음향 센서 등 실용적 응용을 위한 기초 연구가 두드러집니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Two-dimensional (2D) transition metal carbides (MXenes) exhibit outstanding performances in many applications, such as energy storage, optoelectronics, and electrocatalysts. However, colloidal solutions of Ti3C2Tx MXene flakes deteriorate rapidly under ambient conditions due to the conversion of the titanium carbide to titanium dioxide. Here, we discuss the dominant factors influencing the rate of oxidation of Ti3C2Tx MXene flakes, and present guidelines for their storage with the aim of maintai
We have demonstrated a highly stable electric heater made of oxidation-resistant MXene film, which was capable of stable operation in air under highly oxidizing conditions (70 °C, 100% RH).
Understanding the etching mechanisms of MXene and obtaining direct insights into the influence of etchants on structural features and defects are of critical importance for improving MXene properties, optimization of etching protocols, and exploring new MXene compositions. Despite their importance, such studies have been challenging because of the monoatomic thickness of the A-element layers being etched and aggressive etchants that hinder in situ studies. Here, we visualize the etching behavior
Catalytic reaction between PVA-capped AgNPs and hydrogen peroxide, and the corresponding LSPR optical absorbance spectra as a function of time.
Lithium-sulfur (Li-S) batteries are one of the main challenges facing Li-ion technology because the insulating nature of sulfur and the shuttle phenomenon of dissolved lithium polysulfides (LPSs) in liquid electrolytes result in critical problems, including low Coulombic efficiency, loss of active material, and rapid capacity decay. Here, we oxidized delaminated transition metal carbides (MXenes) using CO<sub>2</sub> (Oxi-d-MXenes) and used them as both cathode electrode with sulfur and modified
We report an artificial eardrum using an acoustic sensor based on two-dimensional MXene (Ti<sub>3</sub>C<sub>2</sub>T<i>x</i>), which mimics the function of a human eardrum for realizing voice detection and recognition. Using MXene with a large interlayer distance and micropyramid polydimethylsiloxane arrays can enable a two-stage amplification of pressure and acoustic sensing. The MXene artificial eardrum shows an extremely high sensitivity of 62 kPa<sup>-1</sup> and a very low detection limit
MXenes have attracted great attention for their potential applications in electrochemical and electronic devices due to their excellent characteristics. Traditional sound sources based on the thermoacoustic effect demonstrated that a conductor needs to have an extremely low heat capacity and high thermal conductivity. Hence, a thin MXene film with a low heat capacity per unit area (HCPUA) and special layered structure is emerging as a promising candidate to build loudspeakers. However, the use o
In the current work, we followed a green chemistry route to prepare and characterize the silver nanoparticles (AgNPs) using Syzygium aromaticum (clove) extract at room temperature. Suitably, the clove extract acted as a reducing agent as well as a capping agent, and these reactions occurred rapidly. The formation of the AgNPs was confirmed by the observation of the distinct absorption peak at a wavelength of 418 nm using ultraviolet–visible (UV–Vis) spectroscopy, and a morphological study confir
Abstract Electro‐ionic soft actuators, capable of continuous deformations replacing non‐compliant rigid mechanical components, attract increasing interest in the field of next‐generation metaverse interfaces and soft robotics. Here, a novel MXene (Ti 3 C 2 T x ) electrode anchoring manganese‐based 1,3,5‐benzenetricarboxylate metal‐organic framework (MnBTC) for ultrastable electro‐ionic artificial muscles is reported. By a facile supramolecular self‐assembly, the Ti 3 C 2 T x ‐MnBTC hybrid nanoar
Abstract Developing a highly effective interlayer inserted between the sulfur electrode and separator is one of the most important issues in Li–S battery research, because this interlayer enhances the cycle performance of the Li–S battery by trapping the lithium polysulfides in the sulfur electrode. Among various interlayer materials, carbon materials such as graphene and carbon nanotubes are particularly appealing because of their high electrical conductivity. Here, a new flexible carbon membra
Skin-attachable gas sensors provide a next-generation wearable platform for real-time protection of human health by monitoring environmental and physiological chemicals. However, the creation of skin-like wearable gas sensors, possessing high sensitivity, selectivity, stability, and scalability (4S) simultaneously, has been a big challenge. Here, an ionotronic gas-sensing sticker (IGS) is demonstrated, implemented with free-standing polymer electrolyte (ionic thermoplastic polyurethane, i-TPU) a