Article
Chemistry, Physical
Chi Zhang, Xiurong Yang, Zihan Zhang, Jiachen Li, Wujing Jin, Haixia Ma
Summary: In this study, the decomposition mechanism of ammonium perchlorate (AP) on graphitic carbon nitride (g-C3N4) catalyst was investigated using density functional theory calculation. The main decomposition pathway of AP was found to be HClO4 -> ClO3- -> ClO2- -> ClO- -> Cl-. Additionally, the oxidation of g-C3N4 surface weakened its catalytic capacity for AP decomposition but enhanced its catalytic capacity for the adsorption and dehydrogenation of NH3.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Inorganic & Nuclear
Anna Ya Kozmenkova, Vladislava A. Timofeeva, Badma N. Mankaev, Andrey Lalov, Evgeniya A. Saverina, Mikhail P. Egorov, Sergey S. Karlov, Mikhail A. Syroeshkin
Summary: Germylenes, organic compounds of divalent germanium, are efficient in oxidative addition and reductive elimination reactions. The study used cyclic voltammetry to characterize germylenes with different stabilizing groups and found that they undergo irreversible oxidation within a specific potential range. The use of stabilizing groups improves germylene stability and fine-tunes their ability to participate in oxidative addition reactions, as shown by quantum chemical calculations.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Analytical
Shi-Hua Chen, Zong-Yin Song, Xiang-Yu Xiao, Hong-Qi Huang, Yuan-Fan Yang, Pei-Hua Li, Meng Yang, Xing-Jiu Huang
Summary: Vacancy and doping engineering were used to improve the electrocatalytic ability of nanomaterials for detecting heavy metal ions. The P-doped material showed enhanced sensitivity and selectivity towards As(III), and the vacancies provided abundant electrons to form active centers.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Physical
Donghyeon Kang, Hyeon Yeong Lee, Joon-Ha Hwang, Sera Jeon, Dabin Kim, SeongMin Kim, Sang-Woo Kim
Summary: This study investigated the impact of molecular structure deformation on the triboelectric properties of PTFE induced by contact force using density functional theory (DFT). The results showed that deformation enhanced the negative triboelectric property of PTFE mainly due to the electron-deficient state of carbon atoms leading to enhanced local dipole.
Article
Biochemistry & Molecular Biology
Eugenia P. Kramarova, Alexander D. Volodin, Vadim V. Negrebetsky, Anastasia D. Shagina, Teimur M. Aliev, Pavel Dorovatovskii, Roman A. Novikov, Anna V. Vologzhanina, Alexander A. Korlyukov
Summary: Hexacoordinated heteroligand silicon catecholates, which are potentially soluble compounds with high hydrolytic stability and diverse redox properties, were synthesized via transesterification and characterized by various analytical techniques. The compounds showed high hydrolytic stability and diverse redox properties, with up to three oxidation waves observed.
Article
Nanoscience & Nanotechnology
Longsheng Cao, Dan Li, Travis Pollard, Tao Deng, Bao Zhang, Chongyin Yang, Long Chen, Jenel Vatamanu, Enyuan Hu, Matt J. Hourwitz, Lin Ma, Michael Ding, Qin Li, Singyuk Hou, Karen Gaskell, John T. Fourkas, Xiao-Qing Yang, Kang Xu, Oleg Borodin, Chunsheng Wang
Summary: The study introduces an aqueous zinc battery with a solid-electrolyte interphase that enables excellent performance in various tests, demonstrating its potential for practical applications in energy storage.
NATURE NANOTECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Simon Werner, Tobias Vollgraff, Joerg Sundermeyer
Summary: The chromophore class of 1,3,8,10-tetrasubstituted peropyrenes was effectively synthesized from peropyrenequinone via a Zn-mediated reductive aromatization approach, allowing for a one-step symmetric functionalization of the peropyrene backbone. The study explored the potential use of the synthesized compounds in transition metal catalysed cross couplings, leading to 1,3,8,10-tetraaryl and tetraalkynyl peropyrenes. Investigating the optoelectronic and redox properties of these compounds revealed that introducing various substituents allows for easily tunable HOMO and LUMO energies.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Christianna N. Lininger, Joseph A. Gauthier, Wan-Lu Li, Elliot Rossomme, Valerie Vaissier Welborn, Zhou Lin, Teresa Head-Gordon, Martin Head-Gordon, Alexis T. Bell
Summary: Density Functional Theory (DFT) is the most tractable choice for understanding mechanistic pathways in electrocatalytic processes like CO2 or CO reduction. The study found that the surface modified RPBE functional performs reliably in many benchmarks, while meta-GGA functionals also show promising results. Among them, B97M-rV predicts the correct site preference for CO binding on Ag and Au, while RTPSS performs well for surface relaxations and CO binding on Pt and Cu.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Yunhao Sun, Zhengxing Dai, Gulou Shen, Xiaohua Lu, Xiang Ling, Xiaoyan Ji
Summary: This study improves the efficiency of the ePC-SAFT-DFT calculation for confined systems by combining the Chebyshev pseudo-spectral collocation method with the Anderson mixing algorithm. The study systematically investigates the effects of temperature, pressure, pore size, and pore shape on CO2 solubilities in silica-nanopore-confined ionic liquids (ILs). The results suggest that using silica material with narrow spherical pores and selecting IL-anions that have a significant impact on absorption enhancement can achieve high CO2 solubilities.
FRONTIERS IN CHEMISTRY
(2022)
Article
Engineering, Environmental
Fansong Liu, Qiujing Xu, Huizhi Liang, Haiying Wang, Cheng Zhong, Xiaobo Min, Liyuan Zhang
Summary: Stabilization of arsenic sulfur slag is crucial to prevent environmental pollution, but the molecular understanding of its stability is lacking, hindering the development of effective solutions. By studying the structure-stability relationship of As-S slag, the most stable structure was identified and a successful excess-S-based hydrothermal method was proposed to promote stabilization. This method significantly reduced the arsenic concentration in the leaching test, demonstrating its effectiveness compared to other methods.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Chemistry, Physical
Xue-Yun Shang, Hua-Ying An, Ting Zhang, Jin-Hong Lin, Fei Hao, Dong-Hai Yu, Ji-Chang Xiao, Tian-Duo Li
Summary: This study quantitatively described the affinity of fourteen metal ions and two representative ligands using density functional theory, and explored different methods to understand the evolution of affinity.
CHEMICAL PHYSICS LETTERS
(2021)
Article
Electrochemistry
Xiaozhong Wu, Hua Li, Xinping Yang, Xin Wang, Zhichao Miao, Pengfei Zhou, Jin Zhou, Shuping Zhuo
Summary: The hierarchically porous carbon (HPC) prepared using silica as a template exhibits high specific surface area and F, N co-doping, resulting in high specific capacitance and superior pseudocapacitance in KI-additive electrolyte. The HPC also shows a higher operation voltage and energy density in the KI-additive electrolyte compared to H2SO4 electrolyte.
ELECTROCHIMICA ACTA
(2021)
Article
Energy & Fuels
Yucen Kuang, Lechi Zhang, Longqi Wu, Xiaoqian Liu, Zhifang Wei, Jingbo Chen, Shengfu Zhang
Summary: Revealing the specific separation behavior of macerals is of great significance for the classification and utilization of coal resources. This article investigates the separation mechanism of macerals during coal upgrading through experimental and computational methods. The analysis of morphological, mineral, and structural differences of macerals reveals that the float-sink procedure with water bath heating achieves high purity for vitrinite and inertinite. The coal particle size and distribution of functional groups on inertinite surface affect the separation behavior.
Article
Mathematics
Job J. Kuit, Eitan Sayag
Summary: This paper further explores the compression cone of a real spherical homogeneous space Z = G/H, and presents a geometric construction of the little Weyl group of Z introduced by Knop and Krotz. The technique used is based on a detailed analysis of limits of conjugates of the subalgebra Lie(H) along one-parameter subgroups in the Grassmannian of subspaces of Lie(G). The little Weyl group is obtained as a finite reflection group generated by the reflections in the walls of the compression cone.
MATHEMATISCHE ANNALEN
(2023)
Article
Materials Science, Multidisciplinary
S. Emad Rezaei, Mona Zebarjadi, Keivan Esfarjani
Summary: The BoltzWann code uses density-functional theory to calculate the material's response to electric field, temperature gradient, and magnetic field. This work introduces a generalized method for calculating the thermomagnetic properties of materials.
COMPUTATIONAL MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Sunwoo Kang, Taekyung Kim
ORGANIC ELECTRONICS
(2020)
Article
Chemistry, Multidisciplinary
Kyo Min Hwang, Sunwoo Kang, Taekyung Kim
Summary: Unusual stepwise increases in efficiency were observed in fluorescent organic light-emitting diodes (OLEDs), which were attributed to exciton formation and shifting of the exciton formation zone (EFZ) from the electron-blocking layer (EBL) to the emitting layer (EML). The correlation between non-linear efficiency characteristics and leakage current was investigated, revealing that the degree of variation in the efficiency curve was directly related to the amount of leakage electrons and excitons. These findings provide insights into the understanding and optimization of OLED performance.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2022)
Article
Chemistry, Applied
Sunwoo Kang, Tae Kyung Kim
Summary: This report investigates the photochemical and electrochemical stability of bis-tridentate Ir(III) phosphors and reveals that the bond strength strongly affects the photo-stability. It also shows that a large delta E((MC)-M-3-T-1) value is detrimental to the chemical stability of high-energy Ir(III) phosphors.
Article
Optics
Jinwon Sun, Heechoon Ahn, Sunwoo Kang, Soo-Byung Ko, Dayoon Song, Hyun Ah Um, Sungbum Kim, Yoonkyoo Lee, Pyungeun Jeon, Seok-Hwan Hwang, Youngmin You, Changwoong Chu, Sunghan Kim
Summary: By using new dopant and host materials, a deep blue phosphorescent organic light-emitting diode with a lifetime exceeding 1,000 hours has been successfully produced. The application of these materials results in longer device lifetimes and higher color purity.
Article
Engineering, Environmental
Ki Ju Kim, Hakjun Lee, Sunwoo Kang, Taekyung Kim
Summary: A novel device architecture with an Ir-complex intermediate energy carrier (IEC) was proposed to create multiple energy transfer channels, leading to an unprecedentedly long lifetime in blue phosphorescent organic light-emitting diodes (PhOLEDs).
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Ju Hui Yun, Jun Su Ha, Yoonkyoo Lee, Sun Woo Kang, Changwoong Choo, Kyung Hyung Lee, Jae -Min Kim, Jun Yeob Lee, Soon Ok Jeon, Hye Jin Bae, Minsik Min, Sangho Park, Hwang Suk Kim, Hye Sung Choi, Hyeonho Choi
Summary: Understanding and mitigating materials degradation in blue PhOLEDs is essential for replacing fluorescent devices with efficient phosphorescent ones. Incorporating novel n-type hosts can significantly enhance operational stability and efficiency in blue PhOLEDs, making them a promising option for practical applications.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Sunwoo Kang, Sang Ho Jeon, Taekyung Kim
Summary: The effect of coordinated structures of ETMs with Liq on charge transport characteristics was theoretically investigated. The reorganization energies of holes and electrons of ETM-Liq simultaneously increased, indicating retarded charge transport. Interestingly, lambda e of ETM-(Liq)n increased, while lambda h decreased. The transfer integrals for holes and electrons of T2T-Liq and BPyTP2-Liq were significantly reduced, leading to reduced hopping rates of holes in Liq-complexes while increased hopping rate of electrons in BPyTP2-Liq and reduced hopping rate in T2T-Liq/TSPO1-Liq.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Bubae Park, Ki Ju Kim, Hyewon Nam, Bum Joon Park, Sunwoo Kang, Hyoung Yun Oh, Taekyung Kim
Summary: A new concept of integrating exciton donor and acceptor into a single emitting molecule is proposed. By synthesizing 8,9,10,11-tetradeutero-2 '-(9H-carbazol-9-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-N-phenylspiro[benzo[de]anthracene-7,9 '-fluoren]-3-amine (FPA-SBAF-Cz) using 9-(8,9,10,11-Tetradeuterospiro[benzo[de]anthracene-7,9 '-fluoren]-2'-yl)-9H-carbazole (SBAF-Cz) and 8,9,10,11-tetradeutero-N-(9,9-dimethyl-9H-fluoren-2-yl)-N-phenylspiro[benzo[de]anthracene-7,9 '-fluoren]-3-amine (FPA-SBAF) as host and dopant, respectively, the single-component blue OLED with FPA-SBAF-Cz shows higher external quantum efficiency and longer device lifetime compared to OLEDs with multicomponent EMLs.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Sunwoo Kang, Taekyung Kim
Summary: Density functional theory (DFT) calculations were used to investigate the impact of external electric fields (EEFs) on the photo-physical properties of the PXZ-TRZ emitter. The study revealed that the DEST values increased significantly under EEFx/y/z = 5.0 x 106 V/cm due to changes in molecular and electronic structures. In addition, the spin-orbit couplings (SOCs) were greatly enhanced under EEFz = 5.0 x 105 V/cm and EEFy/z = 5.0 x 106 V/cm, while they decreased significantly under EEFy = 5.0 x 105 V/cm and EEFx = 5.0 x 106 V/cm. The calculated reverse intersystem crossing rate (kRISC) values were significantly improved under EEFy/z = 5.0 x 106 V/cm. However, EEFx = 5.0 x 106 V/cm and EEFy = 5.0 x 105 V/cm had a detrimental effect on kRISC. Therefore, the study emphasizes the importance of considering the role of EEFs in characterizing TADF materials in solid-state devices.
MATERIALS TODAY CHEMISTRY
(2023)
Article
Chemistry, Physical
Sang Ho Jeon, Sunwoo Kang
Summary: This study developed a new prediction model for hole injection barriers, which considers the vacuum level shift in adjacent layers and the variation in CoITO as determinants. The effect of p-dopants on the HTL energy level was also taken into account. The predicted HIBs of various anode/organic junctions were consistent with UPS experiments. The developed EEM model can aid in determining suitable HTL/HIL organic materials without significant effort and time costs.
COMPUTATIONAL AND THEORETICAL CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
You Na Song, Sunwoo Kang, Taekyung Kim
Summary: This study introduces the concept of an electron leakage-pathway (ELP) and demonstrates that using an anthracene core with high bond dissociation energy (BDE) as the ELP is the most effective way to increase the lifetime of blue fluorescent organic light-emitting diodes (FOLEDs), achieving over 400 h of LT90. Furthermore, under a commonly used brightness level, an LT50 of over 10,000 h was obtained.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Kyo Min Hwang, Taekyung Kim, Sunwoo Kang
Summary: This study investigates the critical factors affecting the stability of blue OLEDs through theoretical calculations and experiments. It is found that the bond dissociation energy (BDE) in the anionic states of molecules has a greater impact on the lifetime of blue fluorescent OLEDs (BFOLEDs) than the amount of electron leakage to the electron blocking layer (EBL).
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Ki Ju Kim, Kyo Min Hwang, Hakjun Lee, Sunwoo Kang, Soo-Byung Ko, Min-Sik Eum, Young Kwan Kim, Taekyung Kim
Summary: The use of the newly-synthesized DSiCzTrz led to excellent device performance, with a fast reverse intersystem crossing rate and rapid triplet-to-singlet conversion, resulting in significantly improved efficiency and lifetime in the mixed system with mCP.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Chemistry, Physical
Sunwoo Kang, Taekyung Kim, Jin Yong Lee
Summary: A series of Ir- and Pt-based blue phosphorescent materials were theoretically investigated using DFT calculations to improve their chemical stability in the excited state. Introducing intra- and inter-ligand interactions in Ir and Pt complexes significantly increased the Delta E((MC)-M-3-T-1) to prevent decomposition reactions, resulting in the highest reported values to date. The research provides insights into improving device lifetimes by enhancing the excited state chemical stability of deep blue phosphorescent materials.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Chang Yoon Yang, Sunwoo Kang, Hyein Jeong, Ho Jin Jang, Yoonkyoo Lee, Jun Yeob Lee
JOURNAL OF MATERIALS CHEMISTRY C
(2020)
