Article
Chemistry, Physical
Zhuangchai Lai, Qiyuan He, Thu Ha Tran, D. V. Maheswar Repaka, Dong-Dong Zhou, Ying Sun, Shibo Xi, Yongxin Li, Apoorva Chaturvedi, Chaoliang Tan, Bo Chen, Gwang-Hyeon Nam, Bing Li, Chongyi Ling, Wei Zhai, Zhenyu Shi, Dianyi Hu, Vinay Sharma, Zhaoning Hu, Ye Chen, Zhicheng Zhang, Yifu Yu, Xiao Renshaw Wang, Raju Ramanujan, Yanming Ma, Kedar Hippalgaonkar, Hua Zhang
Summary: A general synthetic method for large-scale preparation of high-purity metastable 1T'-phase transition metal dichalcogenide crystals, including WS2, WSe2, MoS2, MoSe2, WS2xSe2(1-x) and MoS2xSe2(1-x), has been reported. The crystal structures of 1T'-WS2, -WSe2, -MoS2 and -MoSe2 were solved using single-crystal X-ray diffraction. The as-prepared 1T'-WS2 showed thickness-dependent intrinsic superconductivity, demonstrating critical transition temperatures of 8.6 K for a thickness of 90.1 nm and 5.7 K for a single layer, attributed to its high intrinsic carrier concentration and semi-metallic nature. This synthesis method will facilitate a more systematic investigation of the intrinsic properties of metastable TMDs.
Article
Chemistry, Multidisciplinary
Hyeokjung Lee, Hyowon Han, Chanho Park, Jin Woo Oh, Hong Hee Kim, Sohee Kim, Min Koo, Won Kook Choi, Cheolmin Park
Summary: In this research, non-destructive dispersants CsPbX3 are utilized to disperse TMD nanosheets and enhance their photodetection properties, eliminating the need to remove the dispersant. CsPbCl3 NCs efficiently withdraw electrons from MoSe2 nanosheets and suppress dark current, resulting in flexible near-infrared MoSe2 photodetectors with high detectivity.
Article
Polymer Science
Takaya Ikami, Yuki Watanabe, Hiroki Ogawa, Mikihito Takenaka, Norifumi L. Yamada, Makoto Ouchi, Hiroyuki Aoki, Takaya Terashima
Summary: By controlling the composition of the copolymers with octadecyl groups and hydroxyethyl groups in solution, ordered lamellar structures can be formed in the solid state, while spin-coating the polymer solutions onto silicon substrates allows the copolymers to autonomously form multilayered lamellar thin films.
Article
Optics
Min-Soo Hwang, Hong-Gyu Park
Summary: Lithographically designed potential wells in monolayer WS2 microcavities can manipulate nonlinear transition-metal dichalcogenide polaritons and enhance the interaction strength between polaritons and the reservoir.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Li-Yun Su, Hsin-Hsiang Huang, Yan-Cheng Lin, Guan-Lin Chen, Wen-Chang Chen, Wei Chen, Leeyih Wang, Chu-Chen Chueh
Summary: In this study, interfacial engineering using an amphiphilic dendritic block copolymer (DBC) and gold nanoparticles (NPs) was demonstrated to enhance the performance and thermal stability of non-fullerene bulk-heterojunction organic photovoltaic devices. The newly developed DBC@AuNPs interlayer improved device efficiency by enabling better energy-level alignment and enhanced interfacial compatibility at the ZnO/BHJ interface, showing great potential for commercialization with a T(80)lifetime of over 1.79 years at room temperature.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Min Liu, Zachary M. M. Hudson
Summary: The first synthesis of hierarchical porous metal-organic frameworks (HP-MOFs) is achieved through the self-assembly of polystyrene-block-poly(ethylene oxide) (PS-b-PEO) and MOF building blocks induced by solvent evaporation. The use of PS-b-PEO as a template allows for the formation of confined spaces that lead to the creation of mesopores and/or macropores after the removal of PS-b-PEO. This approach overcomes phase separation and competitive interactions, and can produce both amorphous and crystalline HP-MOFs. Furthermore, HP-MOFs with honeycomb-like channels exhibit enhanced incorporation of large guest molecules compared to microporous MOFs.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Polymer Science
Huiying Wang, Qiang Chen, Zhen Geng, Jingyi Rao, Bijin Xiong, Frederic Lortie, Julien Bernard, Wolfgang H. Binder, Senbin Chen, Jintao Zhu
Summary: By introducing 2,6-diaminopyridine moieties and H-bonding amphiphilic interactions, a simple and effective self-assembly strategy was designed to form giant vesicles with a diameter of approximately 3 μm, providing a new opportunity for the design of supramolecular polymers.
Article
Chemistry, Multidisciplinary
Hengli Lu, Jihu Wei, Kaiyuan Liu, Zihua Li, Tianyang Xu, Dong Yang, Qiuming Gao, Huijing Xiang, Guodong Li, Yu Chen
Summary: A dual-functional medication has been developed to protect cartilage and repair subchondral bone simultaneously. Black phosphorus nanosheets (BPNSs) effectively eliminate intracellular reactive oxygen species (ROS), restore chondrocyte function, and regulate inflammation, providing disease-modifying effects on osteoarthritis (OA). In vivo assessments confirm that BPNSs inhibit cartilage degradation and prevent OA progression, making them a competitive candidate for OA treatment.
Article
Polymer Science
Qianyu Lin, Chen Chuan Lim, Cally Owh, Joey Hui Min Wong, Valerie Ow, Belynn Sim, Yi Jian Boo, Michelle P. Y. Yew, Yi Hao Leow, Liangfeng Guo, Jason Y. C. Lim, Xian Jun Loh
Summary: Thermogels are a type of supramolecular hydrogels that undergo reversible sol-gel phase transitions and their unique properties depend on the hydrophilic-hydrophobic balance of the constituent polymers. Most thermogelling polymers use polyethylene glycol (PEG) as the hydrophilic segment, but this study introduces PEG-free amphiphilic polymers comprising only polyethylenimine (PEI) and polypropylene glycol (PPG) as the hydrophilic and hydrophobic segments, respectively. These polymers can self-assemble into micelles and supramolecular gel matrices. By modifying the PEI-PPG copolymers with benzyl groups, the resulting thermogel properties can be conveniently modulated. The hydrophobic-hydrophilic balance of the copolymers can also be adjusted to tune the critical gelation concentrations, gelation temperatures, and gel viscoelastic properties. In addition, the PEI segment exhibits pH-responsiveness, allowing for further alteration of thermogel viscoelasticity through pH adjustment. The convenience of postsynthetic functionalization, new material properties, and dual stimuli-responsiveness of these polycationic PEI-PPG thermogels can potentially offer a vast material design space for many unique applications.
Article
Polymer Science
Xiao-Hui Guo, Ge-Ge Gu, Tian-Jun Yue, Wei-Min Ren
Summary: In this study, a new method for synthesizing amphiphilic block copolymers comprised of acidified polyamine and polycarbonate segments was developed through the orthogonal polymerization of aziridine and cyclic carbonates. Controlled experiments demonstrated that the cationic ring-opening polymerization (ROP) of aziridine and the anionic ROP of cyclic carbonates occurred simultaneously, resulting in chain propagation. This approach enables the construction of amphiphilic block copolymers and the formation of polysomes through acidification.
Article
Optics
Battulga Munkhbat, Betul Kucukoz, Denis G. Baranov, Tomasz J. Antosiewicz, Timur O. Shegai
Summary: Transition metal dichalcogenides (TMDs), including semiconducting WS2, in-plane anisotropic ReS2, and metallic TaSe2, TaS2, and NbSe2, have attracted significant attention due to their exceptional optical, excitonic, mechanical, and electronic properties. Nanostructured multilayer TMDs, with their high refractive indices and optical anisotropy, show promise for nanophotonic applications. Advanced nanofabrication strategies, including careful selection of resists for electron beam lithography and etching methods, are discussed, with a specific focus on non-conductive substrates such as SiO2. These TMD-based nanostructures have the potential to impact high-index nanophotonics, plasmonics, and on-chip optical circuits.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Physical
V. Sethi, D. Runacres, V. Greenacre, Li Shao, A. L. Hector, W. Levason, C. H. de Groot, G. Reid, R. Huang
Summary: In this study, WS2xSe2-2x (0 <= x <= 1) binary and ternary thin films were successfully deposited using single source precursors [WECl4(E'Bu-n(2))] (E = S or Se; E' = S or Se) through low-pressure chemical vapour deposition. The deposits were characterized by grazing-incidence X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy, confirming their phase purity and stoichiometry. Hall measurements revealed high electrical conductivities for the films, which can be tuned through an annealing process by manipulating Se and S vacancies. The thermoelectric capabilities of the WS2xSe2-2x films were evaluated using variable-temperature Seebeck measurements, showing a peak power factor of 6 mu W m(-1) K-2 for the as-deposited WS2 film at 553 K.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Review
Chemistry, Multidisciplinary
Xin Wang, Jing Wu, Yuwei Zhang, Yu Sun, Kaikai Ma, Yong Xie, Wenhao Zheng, Zhen Tian, Zhuo Kang, Yue Zhang
Summary: Vacancy defect engineering has been widely used to shape the physicochemical properties of diverse catalysts. This review provides a comprehensive understanding of vacancy engineering in 2D TMDs-based electrocatalysis, covering its background, manufacturing, characterization, and application in the hydrogen evolution reaction. The review also explores the correlations between specific vacancy regulation routes and catalytic performance improvement, and discusses the future prospects of vacancy engineering in advanced defect catalysts.
ADVANCED MATERIALS
(2023)
Article
Polymer Science
Yanyao Zhang, Yusheng Tang, Junliang Zhang, Simon Harrisson
Summary: The fluorescence properties of the copolymer can be adjusted by rationally designing the copolymer structure. The asymmetric diblock copolymer shows a gradual increase in fluorescent intensity as the environmental pH decreases, in contrast to the limited and stepwise change of its symmetric block counterpart.
Article
Polymer Science
Mingtao Zhou, Shengfei Wang, Aishun Ding, Guolin Lu, Xiaoyu Huang, Xue Jiang, Binbin Xu
Summary: This study presents the controlled synthesis of polyallene-based diblock copolymers with tunable structure and low polydispersities via reversible addition-fragmentation chain transfer (RAFT) polymerization, highlighting the in situ formation of unique nanofibers based on PNIPAM-b-PPOA diblock copolymer through polymerization-induced self-assembly (PISA). The work opens a new avenue for synthesizing well-defined polyallene-based copolymers and nanoparticles for broad applications using living/controlled radical polymerization.
Article
Nanoscience & Nanotechnology
Jong-Min Ju, Chi Ho Lee, Jung Hyun Park, Jun-Hyeong Lee, Hajin Lee, Jae-Hoon Shin, Seon-Yeong Kwak, Sang Uck Lee, Jong-Ho Kim
Summary: Covalent organic frameworks (COFs) are promising candidates for the controllable design of electrocatalysts. In this study, imidazolium-rich COFs (IMCOFs) with well-defined active sites and characteristic three-dimensional assembly structures were prepared, and their electronic structures were tuned by Co incorporation to elicit bifunctional electrocatalytic activities for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The Co nanoparticle-incorporated IMCOF-derived electrocatalyst exhibited lower overpotentials for the ORR and OER compared with the atomic Co-incorporated IMCOF-derived electrocatalyst. Computational simulations revealed that the imidazole carbon sites of the CoNP-s-IMCOF were the active sites for the ORR and OER, and its p-band center downshifted via charge transfer, facilitating the chemisorption of oxygen intermediates during the reactions. A Zn-air battery with the CoNP-s-IMCOF showed a small voltage gap and excellent durability.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Engineering, Electrical & Electronic
Heon-Yul Ryu, Chi Ho Lee, Sang Uck Lee, Satomi Hamada, Nagendra Prasad Yerriboina, Jin-Goo Park
Summary: Corrosion inhibitors are essential additives in metal CMP processes. This study investigated the formation and stability of the Cu/Co-benzotriazole (BTA) complex on Cu and Co surfaces, and found that the Co-BTA complex layer can be removed by a DI water rinse.
MICROELECTRONIC ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Thangjam Ibomcha Singh, Ashakiran Maibam, Dun Chan Cha, Sunghoon Yoo, Ravichandar Babarao, Sang Uck Lee, Seunghyun Lee
Summary: Introducing amorphous and ultrathin nanosheets of transition bimetal phosphate arrays as shells over an electronically modulated crystalline core can enhance the kinetics of the oxygen evolution reaction and hydrogen evolution reaction. The optimized electrocatalyst exhibits low overpotentials for both reactions and demonstrates remarkable overall water-splitting activity when used as both anode and cathode.
Article
Chemistry, Physical
Haneul Jin, Hee Soo Kim, Chi Ho Lee, Yongju Hong, Jihyun Choi, Hionsuck Baik, Sang Uck Lee, Sung Jong Yoo, Kwangyeol Lee, Hyun S. Park
Summary: This study investigates the relationship between catalyst geometrical features and their electrochemical nitrogen reduction kinetics by regulating the surface atomic geometry of copper sulfide nanocatalysts. It is found that nanocrystals with highly exposed zigzag (010)-type surfaces exhibit the best nitrogen reduction kinetics.
Article
Nanoscience & Nanotechnology
Nayantara K. Wagh, Sambhaji S. Shinde, Chi Ho Lee, Sung-Hae Kim, Dong-Hyung Kim, Han-Don Um, Sang Uck Lee, Jung-Ho Lee
Summary: In this study, flexible free-standing electrocatalysts with long-lasting durability, high efficiency, and wide temperature tolerance were constructed for commercial zinc-air batteries. The fabricated bifunctional membrane electrocatalysts demonstrated exceptional performance in terms of oxygen bifunctional activity and long-lasting durability. The alkaline Zn-air battery with the constructed air-cathode showed superior power density, capacity, and cycling stability compared to reference materials. Solid-state Zn-air batteries also exhibited high power density, energy density, and cycling stability under harsh conditions.
NANO-MICRO LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Tae Woog Kang, Jun-Hyeong Lee, Jaewoo Lee, Jung Hyun Park, Jae-Hoon Shin, Jong-Min Ju, Hajin Lee, Sang Uck Lee, Jong-Ho Kim
Summary: A zwitterionic covalent organic framework (Zwitt-COF) with well-defined chemical and pore structures is prepared as a solid electrolyte, which can accelerate the dissociation and transport of Li ions. The Zwitt-COF solid electrolyte exhibits high ionic conductivity and electrochemical stability, leading to superior long-term cycle performance in all-solid-state Li-metal batteries.
ADVANCED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Pallellappa Chithaiah, Ramesh Chandra Sahoo, Jun Ho Seok, Sang Uck Lee, H. S. S. Ramakrishna Matte, C. N. R. Rao
Summary: In this study, NbO2, an anode material with fast charging capabilities and stability, was synthesized using a simple strategy and its applications in Li-ion batteries (LIBs) and Na-ion batteries (SIBs) were investigated. NbO2 showed high specific capacity and remarkable stability in LIBs, as well as unique fast charging capability. In SIBs, NbO2 exhibited high specific capacity and good cycling performance. Density functional theory analysis revealed various features of NbO2 that contribute to the observed battery performances.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Jun-Hyeong Lee, Hajin Lee, Jaewoo Lee, Tae Woog Kang, Jung Hyun Park, Jae-Hoon Shin, Hyunji Lee, Dibyananda Majhi, Sang Uck Lee, Jong-Ho Kim
Summary: In this study, a diethylene glycol-modified pyridinium covalent organic framework (DEG-PMCOF) was developed as a multicomponent solid electrolyte for all-solid-state Li metal batteries. DEG-PMCOF exhibited high ion conductivity and effectively suppressed the formation of Li dendrites and dead Li, leading to a high specific capacity and outstanding Coulombic efficiency during long-term cycling.
Article
Materials Science, Multidisciplinary
Nabeen K. Shrestha, Supriya A. Patil, Jun Ho Seok, Amol S. Salunke, Sangeun Cho, Akbar I. Inamdar, Youngsin Park, Sang Uck Lee, Hyungsang Kim, Hyunsik Im
Summary: Engineering the crystallinity of metal-organic frameworks via Ce-doping can expose active electrocatalytic sites and enhance the oxygen evolution reaction (OER) activity. Optimally Ce-doped MIL-88B(Ni)/NF anode shows lower overpotentials, superior kinetic and turnover frequency for OER. DFT calculations support the Ce3+ ion doping effect on inducing site-selective crystal disorder and enhancing OER electrocatalytic activity.
MATERIALS TODAY PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Jun-Hyeong Lee, Hajin Lee, Jaewoo Lee, Tae Woog Kang, Jung Hyun Park, Jae-Hoon Shin, Hyunji Lee, Dibyananda Majhi, Sang Uck Lee, Jong-Ho Kim
Summary: A multicomponent solid electrolyte based on a diethylene glycol-modified pyridinium covalent organic framework is developed for all-solid-state Li metal batteries. The electrolyte exhibits high ion conductivity and wide electrochemical stability window, suppressing the formation of Li dendrites and dead Li. The all-solid-state LMB with this electrolyte shows high specific capacity and outstanding Coulombic efficiency during long-term cycling.
Article
Chemistry, Physical
Nayantara K. K. Wagh, Dong-Hyung Kim, Chi Ho Lee, Sung-Hae Kim, Han-Don Um, Joseph Sang-Il Kwon, Sambhaji S. S. Shinde, Sang Uck Lee, Jung-Ho Lee
Summary: Heterointerface-promoted sulfur-deficient cobalt-tin-sulfur (CoS1-delta/SnS2-delta) trifunctional electrocatalysts with superb trifunctional activities were synthesized. The alkaline Zn-air batteries using this catalyst exhibited record-high power density and long-cycle life. Theoretical calculations revealed the modulation of electronic structures and d-band centers to facilitate fast electron/proton transport and avoid strong adsorption of intermediate species.
NANOSCALE HORIZONS
(2023)
Article
Chemistry, Physical
Ramesh Chandra Sahoo, Sreejesh Moolayadukkam, Jun Ho Seok, Sang Uck Lee, H. S. S. Ramakrishna Matte
Summary: Layered double-hydroxides (LDHs) have been extensively researched for their advantages in lithium-ion batteries (LIBs), but their poor electronic conductivity, volume change, and ion diffusion limitations hinder their performance. To overcome these challenges, expanded graphite (EG) was used as a conductive additive to anchor Ni2Co-LDH on its surface. The resulting Ni2Co-LDH/EG composites exhibited significantly enhanced charge-storage capacities and battery-like behavior. Density functional theory (DFT) calculations suggest that the stable Li-ion intercalation in Ni2Co-LDH/EG is attributed to the interaction energy and overlap of lithium and carbon.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Nanoscience & Nanotechnology
Pallellappa Chithaiah, Ramesh Chandra Sahoo, Jun Ho Seok, Sang Uck Lee, H. S. S. Ramakrishna Matte, C. N. R. Rao
Summary: This study presents a simple synthetic strategy to obtain NbO2 as an anode material for LIB and SIB. NbO2 demonstrated high specific capacity, remarkable stability, and fast charging capability in both LIB and SIB. The excellent battery performances of NbO2 are attributed to various factors such as bulk and surface charging processes, lower ion diffusion energy barriers, and superior electronic conductivity.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Akbar I. Inamdar, Harish S. Chavan, Jun Ho Seok, Chi Ho Lee, Giho Shin, Sunjung Park, Seungun Yeon, Sangeun Cho, Youngsin Park, Nabeen K. Shrestha, Sang Uck Lee, Hyungsang Kim, Hyunsik Im
Summary: In this study, NixFeyMoz layered double hydroxide electrocatalysts were fabricated via a simple hydrothermal technique for overall water splitting in an alkaline medium. The best-performing catalysts showed high current density at low cell voltage and exhibited outstanding stability.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Chemistry, Physical
Silabrata Pahari, Shuhao Liu, Chi Ho Lee, Mustafa Akbulut, Joseph Sang-Il Kwon
Summary: Recent studies have identified that solvated amphiphiles can form nanostructured self-assemblies, known as dynamic binary complexes (DBCs), in the presence of ions. This research combines small angle X-ray scattering (SAXS) experiments and coarse-grained Monte Carlo (CGMC) simulations to determine the detailed three-dimensional nanostructure of DBCs, as well as explain the pH tunability of the system.
