Article
Materials Science, Multidisciplinary
Chia-Nan Yeh, Avijit Shee, Sergei Iskakov, Dominika Zgid
Summary: The GFCCSD method provides satisfactory descriptions for weakly and moderately correlated impurities of large sizes, but instability in searching for particle numbers arises when dealing with strongly correlated impurities, especially with larger sizes and multiple degenerate orbitals with strong correlations. Verification from a GFCC solver with higher order excitations is necessary for fully checking the reliability of GFCCSD results.
Article
Chemistry, Physical
Jian Zhou, Yibo Dou, Tao He, Awu Zhou, Xiang-Jing Kong, Xue-Qian Wu, Tongxin Liu, Jian-Rong Li
Summary: Experimental and theoretical studies demonstrate that substitution of selenium and sulfur can enhance the electronic structure and catalytic activity of NiCo2X4/CP (X = O, S, and Se), leading to a lower working voltage in alkaline electrolyzers.
Article
Chemistry, Applied
Xiaodong Zhang, Yajiao Zhou, Hang Zhang, HuangJingWei Li, Kang Liu, Hongmei Li, Hao Pan, Junhua Hu, Junwei Fu, Shanyong Chen, Min Liu
Summary: An environmentally friendly and low-cost NiZn alloy catalyst has been developed for CO2RR to formate, exhibiting high Faraday efficiency and stability. Theoretical calculations suggest that the middle valence electron structure of the NiZn alloy is favorable for formate formation and unfavorable for hydrogen and CO production. UV photoelectron spectroscopy results confirm the modulated valence electron structure of the NiZn alloy compared to Ni and Zn.
JOURNAL OF ENERGY CHEMISTRY
(2021)
Article
Chemistry, Physical
Christoph Baeumer, Jiang Li, Qiyang Lu, Allen Yu-Lun Liang, Lei Jin, Henrique Perin Martins, Tomas Duchon, Maria GloEss, Sabrina M. Gericke, Marcus A. Wohlgemuth, Margret Giesen, Emily E. Penn, Regina Dittmann, Felix Gunkel, Rainer Waser, Michal Bajdich, Slavomir Nemsak, J. Tyler Mefford, William C. Chueh
Summary: The composition of LaNiO3 thin film surfaces dictates surface transformation and the activity of the oxygen evolution reaction, with Ni termination being significantly more active than La termination in the initial state. Active surface phases only develop for select as-synthesized surface terminations.
Article
Chemistry, Multidisciplinary
Shao-Pin Chiu, Vivek Mishra, Yu Li, Fu-Chun Zhang, Stefan Kirchner, Juhn-Jong Lin
Summary: We observe enhanced interfacial two-component superconductivity with a dominant triplet component in nonmagnetic CoSi2/TiSi2 superconductor/normal-metal planar heterojunctions. This is achieved by detecting odd-frequency spin-triplet even-parity Cooper pairs in the diffusive normal-metal part of T-shaped proximity junctions. The transition temperature enhancement can be tuned by up to a factor of 2.3 and the upper critical field increases by up to a factor of 20 by modifying the diffusivity of the normal-metal part. The findings are attributed to the C49 phase of TiSi2 stabilized in confined geometries and are supported by a Ginzburg-Landau model and the quasi-classical theory. Our results are also relevant to the enigmatic 3-K phase reported in Sr-2 RuO4.
Article
Materials Science, Multidisciplinary
F. Garmroudi, M. Parzer, M. Knopf, A. Riss, H. Michor, A. V. Ruban, T. Mori, E. Bauer
Summary: The experimental results on disorder-tuned Fe2VAl0.9Si0.1 alloys and realization of metastable A2 structure in bulk Fe2VAl-based alloys provide insights into the structure-property relationship of Heusler compounds. The study shows that increasing disorder leads to a gradual transition from a semimetal/narrow-gap semiconductor to a metal, and the disordered A2 phase exhibits a large anomalous Hall effect due to side-jump scattering of charge carriers at the antisite magnetic moments.
Article
Materials Science, Multidisciplinary
T. Watanabe, R. Okada, K. Tomiyasu
Summary: Ultrasound velocity measurements reveal two types of symmetry-resolved elastic anomaly in the pseudocubic spin-crossover cobaltite LaCoO3 and the lightly Ni-substituted La(Co0.99Ni0.01)O-3. The temperature dependence of the bulk modulus indicates isostructural lattice instability arising from orbital fluctuations, while the temperature dependence of the shear moduli exhibits elasticity crossover arising from spin crossover. The study also shows that the isostructural lattice instability in LaCoO3 is suppressed with Ni substitution, suggesting the suppression of orbital fluctuations.
Article
Chemistry, Multidisciplinary
German E. Pieslinger, Ivana Ramirez-Wierzbicki, Alejandro Cadranel
Summary: The excited-state version of the Creutz-Taube ion prepared via visible light excitation exhibits strong thermalization and electron delocalization properties. This state has a nanosecond lifetime and can be utilized for intermolecular electron transfer.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Engineering, Chemical
Jiankun Li, Fang Xu, Keyu Wang, Juan He, Yixing Wang, Linfeng Lei, Minghui Zhu, Linzhou Zhuang, Zhi Xu
Summary: This study synthesized cobalt-based oxide and chalcogenide (Co3X4, X = O, S, and Se) to investigate the effects of anions on the electronic structure, catalytic performance, and selectivity of seawater oxidation catalysts. Experimental and theoretical results showed that the substitution of S and Se could regulate the electronic structure and d-band center of Co site, enhancing the metallicity of the catalysts. Additionally, anions were able to modulate the energy barrier for preventing the formation of ClO-. Therefore, Co3S4 exhibited stable performance in 0.1 M KOH + 0.6 M NaCl for 100 hours and in neutral seawater for 20 hours.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Physics, Condensed Matter
Kaja Bilinska, Maciej J. Winiarski
Summary: A high-throughput search was conducted to find semiconductors among 153 half-Heusler phases. The band structures, band gaps, and spin-orbit coupling strengths were calculated using the generalized gradient approximation and modified Becke-Johnson GGA methods. Novel semiconductors with potential applications in thermoelectrics were identified, and further experimental synthesis efforts in this field are encouraged.
SOLID STATE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Shiwei Qian, Xiaoshuai Wu, Zhuanzhuan Shi, Xiaofen Li, Xin Sun, Yongjia Ma, Wei Sun, Chunxian Guo, ChangMing Li
Summary: In this study, a hierarchically porous nanowires-material is carefully tuned for an optimal pore structure by adjusting the weight percentage of SiO2-hard template. The as-prepared nanowires are used as an anode in microbial fuel cells, showing significantly improved output power density.
Article
Nanoscience & Nanotechnology
Capucine Tong, Thomas Bidaud, Eero Koivusalo, Marcelo Rizzo Piton, Mircea Guina, Helder Vinicius Avanco Galeti, Yara Galvao Gobato, Andrea Cattoni, Teemu Hakkarainen, Stephane Collin
Summary: Cathodoluminescence mapping is utilized to investigate the electron concentration gradient of Te-doped GaAs nanowires, revealing distinct electron concentration levels and gradients in nanowires grown at different temperatures.
Article
Multidisciplinary Sciences
Md Safin Alam, Md Saiduzzaman, Arpon Biswas, Tanjun Ahmed, Aldina Sultana, Khandaker Monower Hossain
Summary: This study investigates the physical characteristics of AGeF(3) (A = K, Rb) under hydrostatic pressure using density functional theory. The research aims to reduce the electronic band gap of AGeF(3) to improve its optical properties for optoelectronic applications. The results show that the structural parameters are in line with previous studies, and the bonding between atoms becomes stronger under pressure. The application of hydrostatic pressure leads to changes in optical absorption and conductivity, with a lower band gap and improved conductivity observed. The study suggests that AGeF(3) may be suitable for use in optoelectronic devices operating in the visible and ultraviolet spectrum, and the compounds become more ductile and anisotropic under pressure.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Abishek K. Iyer, Jeong Bin Cho, Hye Ryung Byun, Michael J. Waters, Shiqiang Hao, Benjamin M. Oxley, Venkat Gopalan, Christopher Wolverton, James M. Rondinelli, Joon Jang, Mercouri G. Kanatzidis
Summary: The study investigated the crystal structures and optical properties of mixed cation compounds Na1-xKxAsSe2 (x = 0.8, 0.65, 0.5) and Na0.1K0.9AsS2, revealing that the interaction between different ratios of K atoms can affect the properties and band gap of the compounds.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Multidisciplinary Sciences
Alexander Muller, Gauthier J-P Deblonde, Peter Ercius, Steven E. Zeltmann, Rebecca J. Abergel, Andrew M. Minor
Summary: In this work, the authors utilize transmission electron microscopy to characterize highly-radioactive compounds of berkelium and californium, requiring only small amounts of the elements. They find that berkelium exhibits unexpectedly weak spin-orbit coupling, while californium follows a jj coupling scheme.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Inorganic & Nuclear
Sengeni Anantharaj, Kannimuthu Karthick, Palanichamy Murugan, Subrata Kundu
INORGANIC CHEMISTRY
(2020)
Article
Chemistry, Inorganic & Nuclear
Sivasankara Rao Ede, T. K. Bijoy, S. Sam Sankar, P. Murugan, Subrata Kundu
INORGANIC CHEMISTRY
(2020)
Article
Chemistry, Inorganic & Nuclear
Kannimuthu Karthick, T. K. Bijoy, Abinaya Sivakumaran, Abdul Bashith Mansoor Basha, Palanichamy Murugan, Subrata Kundu
INORGANIC CHEMISTRY
(2020)
Article
Chemistry, Multidisciplinary
Olubunmi Kolawole Akiode, Palanichamy Murugan, Abideen Idowu Adeogun, Gboyega Augustine Adebayo, Mopelola Abidemi Idowu
JOURNAL OF NANOPARTICLE RESEARCH
(2020)
Article
Chemistry, Multidisciplinary
Yung-Chang Lin, Jeyakumar Karthikeyan, Yao-Pang Chang, Shisheng Li, Silvan Kretschmer, Hannu-Pekka Komsa, Po-Wen Chiu, Arkady V. Krasheninnikov, Kazu Suenaga
Summary: The study investigates post-growth doping of transition metal atoms in single layers of WSe2, successfully achieving high densities of various types of impurity atoms. The dopants are predominantly confined within nanostripes embedded in the pristine WSe2, with dislocations aiding in the incorporation of dopants and the formation of stripes of TM dopant atoms.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Markus Aapro, Md Nurul Huda, Jeyakumar Karthikeyan, Shawulienu Kezilebieke, Somesh C. Ganguli, Hector Gonzalez Herrero, Xin Huang, Peter Liljeroth, Hannu-Pekka Komsa
Summary: Transition metal chalcogenides are a family of 2D materials currently of high interest, with monolayer manganese selenide synthesized successfully on a NbSe2 substrate showing unique magnetic and electronic properties. The structure resembles that of CuI or a buckled bilayer of h-BN. Experimental results indicate that the monolayer is antiferromagnetic with an unusual out-of-plane ordering.
Article
Engineering, Electrical & Electronic
S. Suba Viveka, T. Logu, N. Ahsan, J. Karthikeyan, P. Murugan, M. Sampath, S. Kalainathan, Arunava Gupta, Y. Okada, K. Sethuraman
Summary: The tailoring of intermediate bands in the CuGa1-xFexS2 chalcopyrite system was studied both theoretically and experimentally. Fe-doped CuGaS2 was found to exhibit intermediate bands at various energy levels, with the optimal Fe concentration determined to be X = 0.05. Various characterization techniques were employed to study the structural and electronic properties of the thin films.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Shadab Saifi, Gargi Dey, Jeyakumar Karthikeyan, A. S. K. Sinha, Arshad Aijaz
Summary: This study reports a facile synthesis method for precious-metal-free HER electrocatalysts, which are composed of metal-organic framework-derived nanostructures and MoS2 or WS2 nanosheets. The synthesized catalysts exhibit good HER performance and high stability in acidic electrolyte. The synergistic cooperation among multicomponents in the catalyst structure contributes to the high-performance HER activity.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Physical
Anwesh Kumar, Hannu-Pekka Komsa, Diksha Praveen Pathak, Balathanigaimani Marriyappan Sivagnanam, A. S. K. Sinha, J. Karthikeyan
Summary: In this study, the edge atomic structures and atomic boundaries in graphitic carbon nitride (g-C3N4) nanoribbons were investigated using density functional theory (DFT). The results showed that nanoribbon structures with mirror twin boundaries (MTBs) had higher structural stability than conventional nanoribbon structures, and curved and corrugated nanoribbons were thermodynamically more stable than planar nanoribbons. Additionally, the electronic structures of nanoribbons with and without MTBs were found to influence the band gap and band edge positions. The unique electronic structures of nanoribbons facilitated the tunable spatial separation of valence and conduction band states, enhancing the lifetime of excited charge carriers. The study also predicted enhanced photocatalytic activity of g-C3N4 nanoribbons over the monolayer, providing new insights into the geometry, electronic structure, and photocatalytic properties of the nanoribbons.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Inorganic & Nuclear
Shadab Saifi, Gargi Dey, J. Karthikeyan, Ravi Kumar, D. Bhattacharyya, A. S. K. Sinha, Arshad Aijaz
Summary: A unique hollow carbon structure made up of single-Ni-atom and NiCo alloy nanoparticles is reported as an efficient electrocatalyst for oxygen reduction reactions in both alkaline and acidic electrolytes. The structure, derived from a metal-organic framework, exhibits superior activity and durability due to the strong coupling between the single-Ni-atom and the NiCo alloy nanoparticles. Furthermore, the carbon structure shows stable performance as a cathode electrode in proton-exchange membrane fuel cells.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Nijagala Munilakshmi, Muduru Srimurali, Janakiram Karthikeyan, Charmathi Nagaraju
Summary: The adsorption of Acid blue dye using novel adsorbents was studied through non-flow batch sorption studies. The study focused on the influence of pH, equilibrium contact time, and floc dose on color removal. Kinetic and equilibrium studies were conducted, along with FTIR and SEM studies to understand the mechanism involved in dye decolorization.
INTERNATIONAL JOURNAL OF CHEMICAL KINETICS
(2023)
Article
Chemistry, Physical
Renna Shakir, Hannu-Pekka Komsa, A. S. K. Sinha, J. Karthikeyan
Summary: This study comprehensively investigates the role of halogen X (X = F, Cl, Br, and I) in improving the CO(2) reduction activity and selectivity of single Mn-atom-based active sites on g-C3N4. The halogen-modified MnN6 active site exhibits high hydrogen evolution reaction tolerance, leading to increased selectivity due to the increased electronic stability originated from half-filled d orbitals of the Mn atom. This research provides insights for the design of new CO2RR catalysts with improved selectivity and efficiency.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Diksha Praveen Pathak, Anwesh Kumar, Balathanigaimani Marriyappan Sivagnanam, A. S. K. Sinha, J. Karthikeyan
Summary: Ammonia, as a carbon-free carrier for hydrogen, plays a critical role in the development of a hydrogen economy. This study investigates the mechanism of ammonia decomposition on the molybdenum-doped iron nitride surface using first-principles calculations. The results show that the introduction of Mo alters the electronic structure of the catalyst and significantly reduces the activation energy for ammonia decomposition. NH3 preferentially adsorbs on Mo sites, while intermediate species NH2 and NH prefer Fe sites for adsorption.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Nanoscience & Nanotechnology
Santosh Semwal, Renna Shakir, Jeyakumar Karthikeyan, Akhoury Sudhir Kumar Sinha, Umaprasana Ojha
Summary: In this study, the authors successfully synthesized NiFeOOH-Co9S8-n intercalated nanostructure arrays with bifunctionality for hydrogen evolution reaction (HER) and sulfion oxidation reaction (SOR). The nanocatalyst exhibited high electrocatalytic activity and sustainable high-efficient H-2 production at low potentials, suggesting its potential for commercial production of H-2 in the future.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
T. K. Bijoy, J. Karthikeyan, P. Murugan