Review
Chemistry, Multidisciplinary
Mengya Liu, Liping Wang, Gui Yu
Summary: Graphene-based moire heterostructures are important for studying condensed matter physics, especially unconventional superconductors. Key aspects include preparation methods, quality improvement, and topological properties. Physical performances are influenced by factors such as twist angle, strain, and regulation of the dielectric environment.
Article
Chemistry, Multidisciplinary
Yonghao Zhu, Oleg V. Prezhdo, Run Long, Wei-Hai Fang
Summary: Twisting angle affects electronic structure, interlayer coupling, and carrier dynamics in bilayer WS2, enhancing hole transfer but slowing down intervalley recombination. Breathing, in-plane and out-of-plane modes play vital roles in carrier transfer and recombination in twisted junctions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Thermodynamics
Wenwu Jiang, Ting Liang, Jianbin Xu, Wengen Ouyang
Summary: This study investigates the thermal transport property of twisted molybdenum disulfide using molecular dynamics simulations. The results show that the cross-plane thermal conductivity is strongly affected by the interfacial twist angle, while the in-plane thermal conductivity is almost unaffected, indicating high anisotropy. Low-frequency phonons dominate the cross-plane and in-plane thermal conductivity of MoS2. Furthermore, the study reveals a significant size dependence for both cross-plane and in-plane thermal conductivities due to the influence of low-frequency phonons.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Chemistry, Multidisciplinary
Yingjie Chen, Baonan Jia, Guoying Qin, Huiyan Zhao, Lihong Han, Pengfei Lu
Summary: High-performance photocatalysts are crucial for harvesting solar energy and producing pollution-free hydrogen and oxygen through water splitting. In this study, we designed 144 van der Waals (vdW) heterostructures by combining different two-dimensional (2D) group III-V MX (M = Ga, In and X = P, As) monolayers to identify efficient photoelectrochemical materials. Using first-principles calculations, we investigated the stabilities, electronic properties, and optical properties of these heterostructures. GaP/InP in a BB-II stacking configuration was selected as the most promising candidate, with a type-II band alignment and suitable gap value for the catalytic reaction under pH = 0. Additionally, the construction of vdW heterostructure improved light absorption. These findings provide insights into the properties of III-V heterostructures and can guide experimental synthesis for photocatalysis applications.
Article
Chemistry, Multidisciplinary
Duan Luo, Jian Tang, Xiaozhe Shen, Fuhao Ji, Jie Yang, Stephen Weathersby, Michael E. Kozina, Zhijiang Chen, Jun Xiao, Yusen Ye, Ting Cao, Guangyu Zhang, Xijie Wang, Aaron M. Lindenberg
Summary: The study utilized ultrafast electron diffraction to simultaneously visualize charge transfer and electron-phonon coupling in MoS2-graphene heterostructures. It was found that the timescale of charge transfer and relaxation varies significantly with twist angle, indicating that twist angle can serve as an additional tuning knob for interlayer charge transfer in heterobilayers. The research deepened the understanding of fundamental photophysical processes in heterostructures, which is important for future applications in optoelectronics and light harvesting.
Article
Chemistry, Multidisciplinary
Hoon Ju Lee, Suk Woo Lee, Hyuntae Hwang, Seong In Yoon, Zonghoon Lee, Hyeon Suk Shin
Summary: The study demonstrates the synthesis of vertical MoS2/WS2 heterostructures on rGO, showing high catalytic activity for the hydrogen evolution reaction. Characterization revealed that MoS2/WS2/rGO exhibited enhanced electrochemical HER performance attributed to fast electron transfer in the heterostructure. This work suggests great potential for TMD-based (photo)electrocatalysts through modification of their morphology and interlayer spacing.
MATERIALS CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Shengwei Li, Yongchang Liu, Xudong Zhao, Qiuyu Shen, Wang Zhao, Qiwei Tan, Ning Zhang, Ping Li, Lifang Jiao, Xuanhui Qu
Summary: The research successfully increased the MoS2 interlayer spacing and enhanced hydrophilicity by innovatively intercalating graphene into MoS2 layers, forming MoS2/graphene nanocomposites with flower-like structures. These composites showed exceptional high-rate capability and long-term cycling stability, paving a new direction for high-performance cathodes in aqueous zinc-ion batteries.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Zhao Liu, Bartosz Szczefanowicz, J. Marcelo J. Lopes, Ziyang Gan, Antony George, Andrey Turchanin, Roland Bennewitz
Summary: Stacked hetero-structures of 2D materials design interactions with electronic and mechanical properties. We investigate the structure, work function, and friction of 1-4 layers MoS2 grown by chemical vapor deposition on epitaxial graphene on SiC(0001). Friction is mainly controlled by adhesion, which is influenced by deformation of layers. Friction decreases with increasing layers due to decreased deformation caused by bending rigidity. Friction dependence on load and bias voltage is due to variations in interface atomic potential corrugation, enhanced by load and bias. Minimal friction is achieved when work function differences are compensated.
Article
Chemistry, Multidisciplinary
Jinglei Han, Fa Cao, Xiaohong Ji
Summary: This study successfully synthesized bilayer MoS2 with various twist angles using CVD method and demonstrated the formation mechanism with MD simulations. Raman and PL analysis confirmed the significant influence of twist angle on the optical properties of twisted bilayer MoS2.
Article
Chemistry, Multidisciplinary
Victor E. P. Claerbout, Paolo Nicolini, Tomas Polcar
Summary: Solid lubricants, particularly molybdenum disulfide, have excellent frictional properties but are affected by humidity. This study used nonequilibrium molecular dynamics simulations to investigate the frictional properties of multilayer MoS2 sliding in water, revealing an energy-driven, rotational dependence of the water network and identifying three distinct frictional regimes based on water coverage. The results highlight the complex interactions between water and MoS2 in affecting friction behavior.
FRONTIERS IN CHEMISTRY
(2021)
Article
Physics, Applied
Huimin Zhu, Wei Zhang, Chao Ye, Jiaqi Shi, Wenxi Lu
Summary: In this study, the friction coefficient of water on graphene/h-BN heterostructures was investigated using molecular dynamics simulations. The results showed a non-monotonic but symmetrical variation with relative interlayer angle. The graphene/h-BN heterostructure is a device with different friction coefficients on both sides and can be adjusted by twisting the relative interlayer angle.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Yanmin Xu, Lihe Yan, Anyi Wang, Feng Tian, Xiaojun Huang, Jin Liu
Summary: The optical nonlinearity of molybdenum disulfide/tungsten disulfide heterostructures was investigated using nanosecond laser Z-scan technology, where enhanced saturable absorption behavior was found. The carrier dynamics in the nonlinear response, as well as the enhancement mechanism of the heterostructures, were further clarified using femtosecond time-resolved transient absorption measurements.
Article
Chemistry, Multidisciplinary
Xiumei Zhang, Luyao Huangfu, Zhengjian Gu, Shaoqing Xiao, Jiadong Zhou, Haiyan Nan, Xiaofeng Gu, Kostya (Ken) Ostrikov
Summary: In this study, large-area vertical MoS2/WS2 heterostructures were synthesized using single-step confined-space chemical vapor epitaxy. By switching the H-2 flow on and off, two different kinds of heterostructures can be obtained, both with high quality. Photodetectors based on isolated MoS2/WS2 heterostructures exhibit excellent performance.
Article
Chemistry, Physical
Yiheng Zhu, Praveen Sreeramagiri, Ganesh Balasubramanian
Summary: In this study, the interaction of molybdenum disulfide (MoS2) with water and its effect on surface wettability were investigated using molecular dynamics simulations. The results showed that the orientation of MoS2 flakes and temperature had a coupled effect on the wettability. Horizontally oriented MoS2 was found to be less hydrophilic than vertically oriented MoS2 due to differences in atomic interactions. Furthermore, an increase in temperature resulted in the transformation of horizontally oriented MoS2 to a relatively hydrophobic surface, while the vertically oriented flakes retained their hydrophilicity due to bond anisotropy.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Thermodynamics
Yixuan Xue, Harold S. Park, Jin-Wu Jiang
Summary: In this study, we demonstrate that the interfacial thermal resistance in graphene/fullerene/graphene sandwiches can be switchable and show a step-like change by varying the number of fullerenes. This switchable phenomenon is achieved by a structural transition between the graphene layers. The study also shows that mechanical strain or temperature variation can achieve the same switchable effect. This work highlights the potential application of sandwich-like nanoscale heterostructures in switchable thermal devices.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Archaeology
Miriam Andrews, Tomas Polcar, Joanna Sofaer, Alistair W. G. Pike
Summary: The study conducted highly controlled laboratory experiments to analyze wear propagation on replica Bronze Age palstave axes with different metallurgy, demonstrating the impact of subtle differences in metallurgy on wear patterns.
Article
Chemistry, Physical
Mengzhou Liao, Paolo Nicolini, Luojun Du, Jiahao Yuan, Shuopei Wang, Hua Yu, Jian Tang, Peng Cheng, Kenji Watanabe, Takashi Taniguchi, Lin Gu, Victor E. P. Claerbout, Andrea Silva, Denis Kramer, Tomas Polcar, Rong Yang, Dongxia Shi, Guangyu Zhang
Summary: MoS2/graphite and MoS2/h-BN interfaces exhibit ultra-low friction coefficients, with edges and interface steps being the main contributors to friction forces; two-dimensional heterostructures offer twist-angle-independent ultra-low friction due to weak interlayer van der Waals interactions and natural lattice mismatch, but the effects of domain edges on friction processes in finite-size interfaces remain unclear.
Article
Chemistry, Physical
Andrea Silva, Jiangming Cao, Tomas Polcar, Denis Kramer
Summary: Alloying is a strategy to tune the properties of compounds, and it can also be applied to 2D materials in nanotechnology. This paper analyzes the phase behavior of 2D alloys in the TMD family, quantifies it using a metastability metric, and provides a guideline for synthesis of TMD binary alloys.
NPJ COMPUTATIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Andrey Bondarev, Abbas Al-Rjoub, Talha Bin Yaqub, Tomas Polcar, Filipe Fernandes
Summary: This study investigates the structure evolution of a multilayered TiSiN/TiN(Ag) coating with heating and oxidation. The results show that the coating has a multilayered structure, with TiSiN layer consisting of Ti-Si-N solid solution grains and amorphous a-SiNx phase, and TiN(Ag) layer consisting of fcc TiN and Ag crystalline phases. Oxidation starts at 800 degrees C, forming rutile-TiO2. The oxidized part of the coating is Ag depleted, except for the top layer containing some Ag clusters. Ag diffuses towards the surface from the oxidized zones. There are no signs of recrystallization or structural changes in the cross-sectional analysis, except for stress relaxation in the non-oxidized part after annealing at 800 degrees C. Ag redistribution or diffusion is not found in the non-oxidized part, suggesting the effectiveness of the multilayered design in mitigating uncontrolled Ag migration towards the surface.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Emanuele Panizon, Andrea Silva, Xin Cao, Jin Wang, Clemens Bechinger, Andrea Vanossi, Erio Tosatti, Nicola Manini
Summary: The understanding of nano-scale friction, governed by atomic arrangements, is incomplete. This study provides a unified understanding of friction by researching the potential energy of contacting surfaces and categorizing contacts into three types based on geometrical features. These types include structurally lubricated contacts, corrugated and interlocked contacts, and a newly discovered directionally structurally lubricated contact. The findings have implications for a wide range of materials in contact.
Article
Energy & Fuels
Dario F. Zambrano-Mera, Rodrigo Espinoza-Gonzalez, Andreas Rosenkranz, Terry J. Harvey, Tomas Polcar, Paulina Valenzuela, William Gacitua
Summary: The study explores the possibility of enhancing erosion resistance in antireflective coatings through Zr-oxide doping and thermal annealing, and demonstrates that this method can improve the longevity and efficiency of solar panels.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2023)
Article
Nanoscience & Nanotechnology
Mengzhou Liao, Andrea Silva, Luojun Du, Paolo Nicolini, Victor E. P. Claerbout, Denis Kramer, Rong Yang, Dongxia Shi, Tomas Polcar, Guangyu Zhang
Summary: Research indicates that twisting dynamics plays a vital role in rotational friction resistance in van der Waals (vdW) homo/heterostructures.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Andrea Mescola, Andrea Silva, Ali Khosravi, Andrea Vanossi, Erio Tosatti, Sergio Valeri, Guido Paolicelli
Summary: This article investigates the frictional response of graphene under different constraints. The experimental results show that when graphene is clamped across a long and narrow groove, the friction coefficient is significant when sliding parallel to the groove and becomes ultralow in the orthogonal direction. Simulations suggest that this is due to the extra anisotropic strain induced from indentation under anisotropic constraints, leading to an anisotropic stiffening of the graphene. The experimental protocol and physical mechanism uncovered in this study may also be applicable to other 2D membranelike materials.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Renato Buzio, Andrea Gerbi, Cristina Bernini, Luca Repetto, Andrea Silva, Andrea Vanossi
Summary: Solution-processed few-layer graphene flakes are used as friction modifiers to achieve low friction and wear at technologically relevant interfaces. Superlubricity has been observed on nanoscale contacts lubricated by individual graphene flakes, but it is unclear if it persists on larger and morphologically disordered contacts. In this study, the friction performance of solution-processed graphene flakes is investigated using colloidal probe atomic force microscopy. The results show that wet-transferred flakes result in an inhomogeneous coating, and different friction dynamics are observed for different material substrates. Numerical simulations confirm the experimental findings and support the use of wet-transferred liquid-processed graphene flakes for achieving superlubricity in micro electromechanical systems.
ACS APPLIED NANO MATERIALS
(2023)
Article
Electrochemistry
Jonathan Peter Charles Allen, Marcin Mierzwa, Denis Kramer, Nuria Garcia-Araez, Andrew L. Hector
Summary: The electrodeposition of PAN is used to reduce thermal runaway in lithium-ion batteries. The PAN-coated graphite electrode showed controlled film thickness and achieved capacities close to uncoated graphite at 25 degrees C. However, thicker polymer coatings resulted in a drastic decrease in capacity beyond 80 degrees C, indicating potential applications for thermal runaway protection.
Article
Chemistry, Multidisciplinary
Diego Lopez-Carballeira, Tomas Polcar
Summary: This study utilizes DFT high-throughput computational screening to analyze and classify 86 million organic structures, identifying thousands of potential organic electrode materials. Among them, 2306 materials are found to have higher monoelectronic reduction potentials and 626 materials have higher energy densities. These materials serve as a valuable starting point for discovering new organic electrode materials.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Mengzhou Liao, Paolo Nicolini, Tomas Polcar
Summary: Layered materials, such as MoS2, graphite, h-BN, and mica, have complex origins of friction on their surfaces. A new method combining a two-dimensional friction force microscope technology and a two-dimensional friction model can separate anisotropic and isotropic friction forces on these atomically flat surfaces. The study reveals the existence of elemental hopping combinations and the isotropic component in total friction, providing insights into the properties of individual friction components and potential applications of solid lubricants.
Article
Materials Science, Multidisciplinary
Jin Wang, Ali Khosravi, Andrea Silva, Michele Fabrizio, Andrea Vanossi, Erio Tosatti
Summary: A freestanding twisted bilayer graphene (TBG) is unstable below a critical twist angle, accompanied by buckling distortion and collapse of bending rigidity. However, as temperature rises, the bending anomaly fades while the buckling persists. Surprisingly, the electronic properties show a lack of zone boundary splittings due to effective single-valley physics.
Article
Materials Science, Multidisciplinary
Julian Holland, Arihant Bhandari, Denis Kramer, Victor Milman, Felix Hanke, Chris-Kriton Skylaris
Summary: The process of Li intercalation is important for Li-ion batteries and the computational modelling of this process can help improve battery materials. In this study, an approach using electrostatic considerations for simulating Li intercalation is presented. By finding favorable sites for Li intercalation using the electrostatic potential from DFT calculations, the method is tested on graphite-based models of anodic carbon and graphite nanoparticles. The approach successfully reproduces Li staging and investigates the electronic structure of the nanoparticle. Open circuit voltages are computed and show reasonable agreement with experiment. The method provides a novel route for simulating the intercalation process and can be applied to complex nanoscale electrode structures.
MATERIALS ADVANCES
(2022)
