Article
Chemistry, Multidisciplinary
Inseong Lee, Mingu Kang, Seohak Park, Cheolmin Park, Hyeonji Lee, Sanggeun Bae, Hyeongjin Lim, Sungkyu Kim, Woonggi Hong, Sung-Yool Choi
Summary: This study proposes a method to heal donor defect states in monolayer MoS2 using oxygen plasma, with an aluminum oxide (Al2O3) barrier layer that protects the MoS2 channel from damage. The successful healing of donor defect states in MoS2 by oxygen atoms, even in the presence of an Al2O3 barrier layer, has been confirmed. The proposed method enhances the channel properties of MoS2.
Article
Nanoscience & Nanotechnology
Mingjie Pu, Wanlin Guo, Yufeng Guo
Summary: Using a combination of non-noble metal atoms and defect-engineered transition metal dichalcogenide (TMD) monolayers, new types of single-atom catalysts for electrochemical CO2RR can be designed, exhibiting better catalytic performance and selectivity. Applying suitable biaxial tensile strains on defect-engineered TMDs can significantly reduce the overpotentials of non-noble metal atoms, with the vacancy defects and charge transfer playing a crucial role in improving catalytic activity.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Henrique A. B. Fonseca, Lucas G. Verga, Juarez L. F. Da Silva
Summary: This study investigates the effects of Fe decoration on WS2 nanoflakes using density functional theory calculations, revealing that Fe enhances the catalytic activity of WS2 nanoflakes. The findings suggest that decorating WS2 nanoflakes with transition metal atoms could be an interesting strategy for exploring alternative catalysts based on two-dimensional materials.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Materials Science, Multidisciplinary
Yuguo Yin, Chao-Sheng Lian, Fanqi Meng, Yaowu Liu, Wei Chen, Lichen Ji, Xinyu Zhou, Zichun Zhang, Qinghua Zhang, Lin Gu, Wenhui Duan, Qi-Kun Xue, Xi Chen, Shuai-Hua Ji
Summary: This study reports the quenched charge density wave (CDW) of 33.3% niobium-intercalated bilayer NbSe2 synthesized by the molecular beam epitaxy method. First-principles calculations show that the absence of CDW in this self-intercalated ultrathin film is due to the strong valence bond and charge transfer between intercalated Nb and NbSe2 layers. Moreover, scanning tunneling spectroscopy reveals a large in-plane upper critical field beyond the Pauli limit of this thin film. These findings not only deepen our understanding of CDW and superconductivity in transition metal dichalcogenides, but also present a novel approach to control many-body electronic states for future electronics.
Review
Chemistry, Physical
Marco Lunardon, Mattia Cattelan, Stefano Agnoli, Gaetano Granozzi
Summary: Transition metal dichalcogenides (TMDCs) are cost-effective and sustainable alternatives to noble metals for producing green hydrogen. Improving their performances can be achieved by activating their basal plane and utilizing point defects, in-plane boundaries, and strain.
CURRENT OPINION IN ELECTROCHEMISTRY
(2022)
Article
Biophysics
Caixia Sun, Xue Zhang, Hao Huang, Ya Liu, Xianwei Mo, Yufei Feng, Jiahong Wang, Wenhua Zhou, Paul K. Chu, Xue-Feng Yu, Wenxin Liu
Summary: Nanozymes with improved catalytic activity and substrate selectivity are achieved through the design of Se-vacancy-rich TiSe2-x@Au nanocomposites, providing a new strategy for rapid and accurate detection of blood glucose.
BIOSENSORS & BIOELECTRONICS
(2023)
Article
Chemistry, Physical
Pernille D. Pedersen, Tejs Vegge, Thomas Bligaard, Heine A. Hansen
Summary: Electrocatalytic CO2 reduction is a promising solution for closing the anthropogenic carbon cycle. Two-dimensional transition metal dichalcogenides (TMDCs) have been shown to effectively reduce CO2 and have potential beyond CO production. In this computational study, the stability of edge configurations, adsorption properties, and aqueous stability of various TMDC materials were investigated. The results indicate that transition metal ditellurides are a promising class of materials for reducing CO2 while limiting HER.
Article
Chemistry, Physical
Pernille D. Pedersen, Tejs Vegge, Thomas Bligaard, Heine A. Hansen
Summary: Two-dimensional transition metal dichalcogenides show promise as catalysts for CO2 reduction, with potential to produce products beyond CO. The stability and adsorption properties of different materials play a significant role in CO2 reduction. Transition metal ditellurides are identified as a promising class of materials.
Article
Chemistry, Multidisciplinary
Yuanhang Ma, Difei Leng, Xuming Zhang, Jijiang Fu, Chaoran Pi, Yang Zheng, Biao Gao, Xiangguo Li, Neng Li, Paul K. Chu, Yongsong Luo, Kaifu Huo
Summary: Activation of the basal planes of MoS2 using sulfur vacancies and transition metal doping can achieve efficient hydrogen and oxygen evolution reactions. This approach can be extended to other TMDs for high-efficiency electrocatalysis.
Article
Chemistry, Multidisciplinary
Yuan Chen, Haidong Liang, Leyi Loh, Yiwei Ho, Ivan Verzhbitskiy, Kenji Watanabe, Takashi Taniguchi, Michel Bosman, Andrew A. Bettiol, Goki Eda
Summary: We observe bound exciton (BX) complex manifolds in monolayer MoSe2 with intentionally created monoselenium vacancies (VSe) using proton beam irradiation. The emission intensity of different BX peaks exhibits contrasting dependence on electrostatic doping near the onset of free electron injection. These complexes, which are more strongly bound than trions and biexcitons, survive up to around 180 K and show moderate valley polarization memory, indicating partial free exciton character.
Article
Materials Science, Multidisciplinary
Saeid Jannati, Ali Aftabi, Ali Rafiei, Mohammad Mehdi Tehranchi
Summary: In this study, the effects of a two-dimensional WS2 layer on the structural and magnetic properties of a cobalt (Co) thin film were investigated. The results showed that the Co layer grown on the WS2 layer had a crystal structure, while the individual Co isolated layer was amorphous. The magnetic hysteresis loop and magnetoresistance measurements revealed the presence of in-plane magnetic anisotropy in the Co/WS2 bilayer, which could be attributed to the formation of Co crystallinity grown on WS2 and orbital hybridization at the Co/WS2 interface.
Article
Chemistry, Multidisciplinary
Anna Zhuravlova, Antonio Gaetano Ricciardulli, Dawid Pakulski, Adam Gorczynski, Adam Kelly, Jonathan N. Coleman, Artur Ciesielski, Paolo Samori
Summary: Chemical sensing of water contamination by heavy metal ions is a severe environmental problem. Two-dimensional transition metal dichalcogenides (TMDs) show potential as chemical sensors due to their high surface-to-volume ratio and unique electrical characteristics, but lack selectivity. In this study, defect-rich MoS2 flakes were functionalized to develop ultrasensitive and selective sensors for cobalt(II) ions. Through a tailored microfluidic approach, a continuous network was formed by healing the sulfur vacancies in MoS2, enabling high control over the assembly of thin and large hybrid films. The developed sensor exhibited a low limit of detection, broad concentration range, and high selectivity towards Co2+ ions.
Article
Chemistry, Physical
Sonu Prasad Keshri, Swapan K. Pati, Amal Medhi
Summary: In this study, we calculate the carrier mobility of monolayer HfSe2 using density functional perturbation theory and Boltzmann transport equation, and accurately determine the experimental value. Compared to the previously used deformation potential model, we find that the strong electron-optical phonon interaction is one of the reasons for the low mobility. The results also show that the spin-orbit coupling significantly affects the mobility and scattering rates.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Guoteng Ma, Wanfu Shen, Soy Daniel Sanchez, Yu Yu, Lidong Sun, Chunguang Hu
Summary: In this study, we theoretically and experimentally investigated the fundamental pseudo-Brewster angle (pBA) of transitional metal dichalcogenides (TMDCs) monolayers coated on dielectric substrates. Our findings showed that the pBA of TMDCs monolayers undergoes significant shifts in the visible region when inserted on a dielectric sapphire substrate, which is closely associated with their excitonic transitions. Additionally, we demonstrated that the pBA has a surprisingly deep sub-monolayer resolution, making it highly sensitive to subtle differences in disconnected monolayers. These results provide important insights for the development of nanophotonic devices and sensors using low-dimensional materials.
APPLIED SURFACE SCIENCE
(2023)
Article
Engineering, Environmental
Gen Li, Xiaoxu Deng, Peng Chen, Xiaodan Wang, Jun Ma, Fei Liu, Shuang-Feng Yin
Summary: In this article, a universal method for the synthesis of compact heterojunction VS2@C3N4 with S vacancies was developed via in situ supramolecular self-assembly method. The material showed outstanding catalytic activity, stability, and hydrogen production rate. The presence of S vacancies resulted in the formation of a compact heterostructure and reduction of the work function, promoting interfacial carriers transfer and surface properties. The core-shell structure also improved the stability of S vacancies. This work not only provides a universal method for the construction of TMD core-shell structure with vacancies, but also deepens our understanding of carrier separation in the vacancies interface for photocatalysis.
CHEMICAL ENGINEERING JOURNAL
(2022)
Review
Chemistry, Multidisciplinary
Aoni Xu, Nitish Govindarajan, Georg Kastlunger, Sudarshan Vijay, Karen Chan
Summary: In this paper, the effects of electrolyte on electrochemical CO2 reduction (eCO2R) are reviewed and the influences of cations, anions and pH on the reaction activity are summarized. The electrolyte affects the eCO2R activity by influencing the reaction intermediates, blocking active sites and tuning the local environment. However, the existing models are not able to predict the experimental trends accurately and further research and development are needed.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Ahmed O. Elnabawy, Roberto Schimmenti, Ang Cao, Jens K. Norskov
Summary: The choice of Cu/ZnO/Al2O3 as the industrial catalyst for methanol synthesis is due to the strong metal support interactions. In this study, DFT calculations reveal that only ZnO and Ga2O3 can partially cover the Cu surface and modify it without diluting the necessary Cu sites for reactants' activation, while other oxides are either too stable or readily cover the Cu surface completely.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Physical
Katja Li, Sarah G. Shapel, Degenhart Hochfilzer, Jakob B. Pedersen, Kevin Krempl, Suzanne Z. Andersen, Rokas Sazinas, Mattia Saccoccio, Shaofeng Li, Debasish Chakraborty, Jakob Kibsgaard, Peter C. K. Vesborg, Jens K. Norskov, Ib Chorkendorff
Summary: The current density and ammonia formation rates were significantly improved by synthesizing high surface area Cu electrodes through hydrogen bubbling templating (HBT) on Ni foam substrates. Increasing the electrolyte salt concentration was found to enhance the stability of the system.
ACS ENERGY LETTERS
(2022)
Article
Chemistry, Physical
Lan Zhou, Hao Li, Yungchieh Lai, Matthias Richter, Kevin Kan, Joel A. Haber, Sara Kelly, Zhenbin Wang, Yubing Lu, R. Soyoung Kim, Xiang Li, Junko Yano, Jens K. Norskov, John M. Gregoire
Summary: Guided by computational screening and high-throughput experiments, rutile CoSb2O6 has been identified as a promising precious-metal-free electrocatalyst for oxygen reduction in acidic media, demonstrating operational stability and favorable energetics.
ACS ENERGY LETTERS
(2022)
Article
Energy & Fuels
Ya-Rong Zheng, Jerome Vernieres, Zhenbin Wang, Ke Zhang, Degenhart Hochfilzer, Kevin Krempl, Ting-Wei Liao, Francesco Presel, Thomas Altantzis, Jarmo Fatermans, Soren Bertelsen Scott, Niklas Morch Secher, Choongman Moon, Pei Liu, Sara Bals, Sandra Van Aert, Ang Cao, Megha Anand, Jens K. Norskov, Jakob Kibsgaard, Ib Chorkendorff
Summary: This study presents a low-iridium mass-selected iridium-tantalum oxide catalyst with high intrinsic activity for acid environments, aiming to improve the efficiency of hydrogen production in water electrolysers. By carefully evaluating oxygen production, the researchers demonstrate that the catalyst exhibits higher activity compared to commercial IrO2.
Article
Chemistry, Multidisciplinary
Gaurav Ashish Kamat, Jose A. Zamora Zeledon, G. T. Kasun Kalhara Gunasooriya, Samuel M. Dull, Joseph T. Perryman, Jens K. Norskov, Michaela Burke Stevens, Thomas F. Jaramillo
Summary: The study investigates the effects of different acid anions on platinum for oxygen reduction/evolution and hydrogen evolution/oxidation reactions. It demonstrates that the ORR performance can be improved 4-fold in nitric acid compared to sulfuric acid, and the HER/HOR performance is similar across all three electrolytes. The combined experimental-theoretical work provides insights for rational design approaches to enhance catalyst activity through microenvironment engineering.
COMMUNICATIONS CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
G. T. Kasun Kalhara Gunasooriya, Melissa E. Kreider, Yunzhi Liu, Jose A. Zamora Zeledon, Zhenbin Wang, Eduardo Valle, An-Chih Yang, Alessandro Gallo, Robert Sinclair, Michaela Burke Stevens, Thomas F. Jaramillo, Jens K. Norskov
Summary: This study presents a combined theoretical-experimental approach to discover and design transition metal antimonates as electrocatalytic materials for the oxygen reduction reaction. The results show that these catalysts exhibit high activity and stability, making them potential candidates for fuel cell devices.
Article
Energy & Fuels
Ifan E. L. Stephens, Karen Chan, Alexander Bagger, Shannon W. Boettcher, Julien Bonin, Etienne Boutin, Aya K. Buckley, Raffaella Buonsanti, Etosha R. Cave, Xiaoxia Chang, See Wee Chee, Alisson H. M. da Silva, Phil de Luna, Oliver Einsle, Balazs Endrodi, Maria Escudero-Escribano, Jorge V. Ferreira de Araujo, Marta C. Figueiredo, Christopher Hahn, Kentaro U. Hansen, Sophia Haussener, Sara Hunegnaw, Ziyang Huo, Yun Jeong Hwang, Csaba Janaky, Buddhinie S. Jayathilake, Feng Jiao, Zarko P. Jovanov, Parisa Karimi, Marc T. M. Koper, Kendra P. Kuhl, Woong Hee Lee, Zhiqin Liang, Xuan Liu, Sichao Ma, Ming Ma, Hyung-Suk Oh, Marc Robert, Beatriz Roldan Cuenya, Jan Rossmeisl, Claudie Roy, Mary P. Ryan, Edward H. Sargent, Paula Sebastian-Pascual, Brian Seger, Ludmilla Steier, Peter Strasser, Ana Sofia Varela, Rafael E. Vos, Xue Wang, Bingjun Xu, Hossein Yadegari, Yuxiang Zhou
Summary: This article reviews recent progress in electrochemical CO2 reduction, discusses the challenges towards commercialization, and highlights opportunities for further research. The goal is to establish a low- or zero-emission carbon cycle.
JOURNAL OF PHYSICS-ENERGY
(2022)
Article
Chemistry, Physical
Sihang Liu, Nitish Govindarajan, Karen Chan
Summary: This study investigates the reaction mechanism of furfural hydrogenation to furfuryl alcohol using density functional theory calculations and microkinetic modeling. The results show that the binding energy of furfural is a good predictor of the activity trends for furfuryl alcohol production. Additionally, Cu-based alloys are found to be the most active catalysts for this reaction.
Article
Multidisciplinary Sciences
Xianbiao Fu, Jakob B. Pedersen, Yuanyuan Zhou, Mattia Saccoccio, Shaofeng Li, Rokas Salinas, Katja Li, Suzanne Z. Andersen, Aoni Xu, Niklas H. Deissler, Jon Bjarke Valbaek Mygind, Chao Wei, Jakob Kibsgaard, Peter C. K. Vesborg, Jens K. Norskov, Ib Chorkendorff
Summary: Ammonia is an important substance in various industries and can also be used as a carbon-free fuel. A new approach using lithium-mediated nitrogen reduction has shown promise in the electrochemical synthesis of ammonia. In this study, a continuous-flow electrolyzer with gas diffusion electrodes was used, and a platinum-gold alloy catalyst was found to be more stable and efficient for the reaction. The results showed a high faradaic efficiency for ammonia production and energy efficiency at optimal conditions.
Article
Chemistry, Physical
Ang Cao, Jens K. Norskov
Summary: Using density functional theory calculations, this work demonstrates that controlling the spin state of magnetic metal surfaces significantly impacts their chemical properties. The adsorption energy of various adsorbates is shown to be stronger on non-spin polarized surfaces compared to spin polarized ground state surfaces. This finding is consistent for Fe, Co, and Ni surfaces, as well as three commonly used exchange-correlation functionals. The origin of this effect is discussed in terms of surface electronic structure, and a simple model based on the d-band model of adsorption is proposed to explain the phenomenon. The study also explores the potential of utilizing spin effects to manipulate surface reactivity, such as through the addition of a metal promotor.
Article
Chemistry, Multidisciplinary
Naiwrit Karmodak, Jens K. Norskov
Summary: In this study, a computational catalyst-screening method was designed to identify potentially interesting single-atom catalysts (SACs) and di-atom catalysts (DACs) for the O-2 reduction reaction (ORR). Four SACs and fifteen DACs with high estimated catalytic activity were identified, some of which showed high stability in both acidic and alkaline media.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Sihang Liu, Nitish Govindarajan, Hector Prats, Karen Chan
Summary: This research develops a microkinetic model based on density functional theory to study the mechanism of Kolbe electrolysis. It reveals that the shift in the rate-determining step and the decarboxylation and dimerization steps determine the activity of the Kolbe reaction on Pt anodes.
Article
Chemistry, Multidisciplinary
Hendrik H. Heenen, Haeun Shin, Georg Kastlunger, Sean Overa, Joseph A. Gauthier, Feng Jiao, Karen Chan
Summary: Nanostructured Cu catalysts have been found to enhance the selectivities and geometric activities for high value C-C coupled products in electrochemical CO(2) reduction reaction. The selectivity mechanism for acetate formation has been elucidated through ab initio simulations, kinetic-transport model, and loading dependent experiments, indicating that the selectivity is influenced by variations in electrolyte pH and local mass transport properties rather than Cu's intrinsic activity.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Ming Ma, Wanyu Deng, Aoni Xu, Degenhart Hochfilzer, Yu Qiao, Karen Chan, Ib Chorkendorff, Brian Seger
Summary: This study presents a simple experimental method to determine the local pH value in high-rate CO electroreduction by measuring the CO2 capture rate. It is found that an increased OH- concentration near the cathodic GDE surface can promote acetate formation and inhibit the formation of other C2+ products. High CO coverage is also found to be necessary for C2+ formation.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)