Antonio Castro Neto
Degree: PhD
Position: Director, Centre for Advanced 2D Materials
Research Type: Theory
Office: S14-06-13
Email: c2dhead@nus.edu.sg
Contact: (65) 6601 2575
CA2DM Publications:
2025 |
Morin, Julien Luc Paul; Dubey, Nileshkumar; Luong-Van, Emma Kim; Yu, Baiqing; Sabino, Clarice Ferreira; Silikas, Nick; Agarwalla, Shruti Vidhawan; Neto, Castro A H; Rosa, Vinicius Graphene nanocoating on titanium maintains structural and antibiofilm properties post-sterilization Journal Article DENTAL MATERIALS, 41 (1), pp. 7-15, 2025, ISSN: 0109-5641. @article{ISI:001391110500001, title = {Graphene nanocoating on titanium maintains structural and antibiofilm properties post-sterilization}, author = {Julien Luc Paul Morin and Nileshkumar Dubey and Emma Kim Luong-Van and Baiqing Yu and Clarice Ferreira Sabino and Nick Silikas and Shruti Vidhawan Agarwalla and Castro A H Neto and Vinicius Rosa}, doi = {10.1016/j.dental.2024.10.009}, times_cited = {0}, issn = {0109-5641}, year = {2025}, date = {2025-01-01}, journal = {DENTAL MATERIALS}, volume = {41}, number = {1}, pages = {7-15}, publisher = {ELSEVIER SCI LTD}, address = {125 London Wall, London, ENGLAND}, abstract = {Objective: To evaluate the impact of sterilization methods on the structural integrity and antimicrobial properties of graphene nanocoating on titanium (GN). Methods: GN was transferred to titanium using wet (WT) or dry transfer (DT) techniques and sterilized using an autoclave (AC), glutaraldehyde (GA), or ethylene oxide (EtO). The GN structure was characterized using Raman spectroscopy before and after sterilization. Additional specimens were characterized by Raman after AC and water jetting. Biofilm formation was assessed before and after AC using colony-forming units (CFU), biofilm biomass, and SEM (uncoated titanium was the control). Three independent samples were used for structural characterization and biofilm quantification. Statistical analyses were conducted using one-way analysis of variance (ANOVA) and Tukey's test (alpha = 0.05). Results: WT and DT demonstrated high structural stability after sterilization and water jetting, with negligible coating quality or coverage loss. GN exhibited lower biofilm formation even after AC sterilization, as shown by the reduction in CFU counts, biofilm biomass, and SEM images compared to the control. Significance: GN demonstrated high resistance to the stresses imposed by all sterilization methods tested, maintaining its structural integrity, resistance to water-jet cleaning, and antibiofilm potential. The findings suggest that standard industrial practices can effectively sterilize highly resilient GN on titanium implants and possibly other biomaterials.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Objective: To evaluate the impact of sterilization methods on the structural integrity and antimicrobial properties of graphene nanocoating on titanium (GN). Methods: GN was transferred to titanium using wet (WT) or dry transfer (DT) techniques and sterilized using an autoclave (AC), glutaraldehyde (GA), or ethylene oxide (EtO). The GN structure was characterized using Raman spectroscopy before and after sterilization. Additional specimens were characterized by Raman after AC and water jetting. Biofilm formation was assessed before and after AC using colony-forming units (CFU), biofilm biomass, and SEM (uncoated titanium was the control). Three independent samples were used for structural characterization and biofilm quantification. Statistical analyses were conducted using one-way analysis of variance (ANOVA) and Tukey's test (alpha = 0.05). Results: WT and DT demonstrated high structural stability after sterilization and water jetting, with negligible coating quality or coverage loss. GN exhibited lower biofilm formation even after AC sterilization, as shown by the reduction in CFU counts, biofilm biomass, and SEM images compared to the control. Significance: GN demonstrated high resistance to the stresses imposed by all sterilization methods tested, maintaining its structural integrity, resistance to water-jet cleaning, and antibiofilm potential. The findings suggest that standard industrial practices can effectively sterilize highly resilient GN on titanium implants and possibly other biomaterials. |
2024 |
Carrio, Juan A G; Echeverrigaray, Sergio G; Talluri, V S S L P; Sudhakaran, Deepa P; Gan, Hui T; Gardeno, Daniel; Friess, Karel; Neto, Antonio Castro H Performance of GO laminated membranes in H2/CO2 separation as a function of the membrane thickness Journal Article INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, 90 , pp. 646-654, 2024, ISSN: 0360-3199. @article{ISI:001332104500001, title = {Performance of GO laminated membranes in H2/CO2 separation as a function of the membrane thickness}, author = {Juan A G Carrio and Sergio G Echeverrigaray and V S S L P Talluri and Deepa P Sudhakaran and Hui T Gan and Daniel Gardeno and Karel Friess and Antonio Castro H Neto}, doi = {10.1016/j.ijhydene.2024.09.435}, times_cited = {0}, issn = {0360-3199}, year = {2024}, date = {2024-10-08}, journal = {INTERNATIONAL JOURNAL OF HYDROGEN ENERGY}, volume = {90}, pages = {646-654}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {Hydrogen gas (H2) is a promising energy carrier capable of replacing fossil fuels and achieving net zero emissions. However, purifying H2 for applications like fuel cells and industrial processes is challenging due to impurities affecting performance. Two-dimensional (2D) materials, particularly graphene-based membranes, are promising for H2 purification due to their unique properties. The hydrogen (H2) permeation capability of graphene-based membranes is particularly significant. This study examines the use of commercial and costeffective graphene oxide (GO) to fabricate multilayer graphene membranes, focusing on the impact of membrane thickness on H2 and CO2 separation. By using a scalable vacuum filtration method to coat porous ceramic substrates, membranes with controlled thicknesses were produced and characterised using AFM, FESEM, XRD, and gas permeation measurements. The study identified an optimal membrane thickness range (4 nm-250 nm) and the GO quantity (0.44 mu g/cm2 to 1.76 mu g/cm2) needed for effective H2/CO2 separation. This research aims to guide the development of cost-effective, mass-produced 2D-based membranes for industrial H2 purification.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Hydrogen gas (H2) is a promising energy carrier capable of replacing fossil fuels and achieving net zero emissions. However, purifying H2 for applications like fuel cells and industrial processes is challenging due to impurities affecting performance. Two-dimensional (2D) materials, particularly graphene-based membranes, are promising for H2 purification due to their unique properties. The hydrogen (H2) permeation capability of graphene-based membranes is particularly significant. This study examines the use of commercial and costeffective graphene oxide (GO) to fabricate multilayer graphene membranes, focusing on the impact of membrane thickness on H2 and CO2 separation. By using a scalable vacuum filtration method to coat porous ceramic substrates, membranes with controlled thicknesses were produced and characterised using AFM, FESEM, XRD, and gas permeation measurements. The study identified an optimal membrane thickness range (4 nm-250 nm) and the GO quantity (0.44 mu g/cm2 to 1.76 mu g/cm2) needed for effective H2/CO2 separation. This research aims to guide the development of cost-effective, mass-produced 2D-based membranes for industrial H2 purification. |
Donato, Katarzyna Z; Koon, Gavin K W; Lee, Sarah J; Carvalho, Alexandra; Tan, Hui Li; Costa, Mariana C F; Tolasz, Jakub; Ecorchard, Petra; Michalowski, Pawel P; Donato, Ricardo K; Neto, Castro A H Disordered metallic carbon materials from graphene edge chemistry Journal Article MATERIALS TODAY, 79 , pp. 49-59, 2024, ISSN: 1369-7021. @article{ISI:001316339100001, title = {Disordered metallic carbon materials from graphene edge chemistry}, author = {Katarzyna Z Donato and Gavin K W Koon and Sarah J Lee and Alexandra Carvalho and Hui Li Tan and Mariana C F Costa and Jakub Tolasz and Petra Ecorchard and Pawel P Michalowski and Ricardo K Donato and Castro A H Neto}, doi = {10.1016/j.mattod.2024.07.011}, times_cited = {0}, issn = {1369-7021}, year = {2024}, date = {2024-09-12}, journal = {MATERIALS TODAY}, volume = {79}, pages = {49-59}, publisher = {ELSEVIER SCI LTD}, address = {125 London Wall, London, ENGLAND}, abstract = {The creation of three dimensional (3D) structures out of two-dimensional (2D) materials while retaining their extraordinary mechanical and transport properties after processing is one of the current great challenges in materials sciences (Ruoff, 2008; Kong et al., 2019; Lin et al., 2019). Guided by density functional theory (DFT) and molecular dynamics (MD) simulations we found a successful route for a sustainable production of 3D metallic carbon materials that are synthesized from pristine 2D graphene flakes with hydrolyzed edges. The edge hydrolysis lead to strong geometrical anisotropy and self-organization in solution before processing. After processing we obtain a 3D carbon structure where 2D graphene flakes are crosslinked by carbon chains with aromatic groups at very mild annealing temperatures (similar to 150 degrees C), eliminating the constraints for achieving the in-situ preparation of conductive carbon structures. These 3D carbon structures preserve microscopic order but are macroscopically disordered, presenting physical properties of anisotropic metallic carbon with large Young modulus (E approximate to 20 GPa), and room temperature thermal (k approximate to 180 W/mK) and electrical (sigma approximate to 300 kS/m) conductivities comparable to ordinary metals.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The creation of three dimensional (3D) structures out of two-dimensional (2D) materials while retaining their extraordinary mechanical and transport properties after processing is one of the current great challenges in materials sciences (Ruoff, 2008; Kong et al., 2019; Lin et al., 2019). Guided by density functional theory (DFT) and molecular dynamics (MD) simulations we found a successful route for a sustainable production of 3D metallic carbon materials that are synthesized from pristine 2D graphene flakes with hydrolyzed edges. The edge hydrolysis lead to strong geometrical anisotropy and self-organization in solution before processing. After processing we obtain a 3D carbon structure where 2D graphene flakes are crosslinked by carbon chains with aromatic groups at very mild annealing temperatures (similar to 150 degrees C), eliminating the constraints for achieving the in-situ preparation of conductive carbon structures. These 3D carbon structures preserve microscopic order but are macroscopically disordered, presenting physical properties of anisotropic metallic carbon with large Young modulus (E approximate to 20 GPa), and room temperature thermal (k approximate to 180 W/mK) and electrical (sigma approximate to 300 kS/m) conductivities comparable to ordinary metals. |
Carvalho, Alexandra; Nair, Vivek; Echeverrigaray, Sergio G; Neto, Antonio Castro H High Capacity NbS2-Based Anodes for Li-Ion Batteries Journal Article ACS OMEGA, 9 (31), pp. 33912-33918, 2024, ISSN: 2470-1343. @article{ISI:001276227300001, title = {High Capacity NbS_{2}-Based Anodes for Li-Ion Batteries}, author = {Alexandra Carvalho and Vivek Nair and Sergio G Echeverrigaray and Antonio Castro H Neto}, doi = {10.1021/acsomega.4c04118}, times_cited = {0}, issn = {2470-1343}, year = {2024}, date = {2024-07-24}, journal = {ACS OMEGA}, volume = {9}, number = {31}, pages = {33912-33918}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {We have investigated the lithium capacity of the 2H phase of niobium sulfide (NbS2) using density functional theory calculations and experiments. Theoretically, this material is found to allow the intercalation of a double layer of Li in between each NbS2 layer when in equilibrium with metal Li. The resulting specific capacity (340.8 mAh/g for the pristine material, 681.6 mAh/g for oxidized material) can reach more than double the specific capacity of graphite anodes. The presence of various defects leads to an even higher capacity with a partially reversible conversion of the material, indicating that the performance of the anodes is robust with respect to the presence of defects. Experiments in battery prototypes with NbS2-based anodes find a first specific capacity of about 1,130 mAh/g, exceeding the theoretical predictions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We have investigated the lithium capacity of the 2H phase of niobium sulfide (NbS2) using density functional theory calculations and experiments. Theoretically, this material is found to allow the intercalation of a double layer of Li in between each NbS2 layer when in equilibrium with metal Li. The resulting specific capacity (340.8 mAh/g for the pristine material, 681.6 mAh/g for oxidized material) can reach more than double the specific capacity of graphite anodes. The presence of various defects leads to an even higher capacity with a partially reversible conversion of the material, indicating that the performance of the anodes is robust with respect to the presence of defects. Experiments in battery prototypes with NbS2-based anodes find a first specific capacity of about 1,130 mAh/g, exceeding the theoretical predictions. |
Koon, Gavin K W; Donato, Katarzyna Z; Carvalho, Alexandra; de Bugallo, Andres Luna; Strupiechonski, Elodie; Donato, Ricardo K; Neto, Castro A H Colossal conductivity anisotropy in 3D metallic carbon films Journal Article CARBON, 228 , 2024, ISSN: 0008-6223. @article{ISI:001253185900001, title = {Colossal conductivity anisotropy in 3D metallic carbon films}, author = {Gavin K W Koon and Katarzyna Z Donato and Alexandra Carvalho and Andres Luna de Bugallo and Elodie Strupiechonski and Ricardo K Donato and Castro A H Neto}, doi = {10.1016/j.carbon.2024.119316}, times_cited = {1}, issn = {0008-6223}, year = {2024}, date = {2024-06-12}, journal = {CARBON}, volume = {228}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {Harnessing the phenomena of quantum coherence and destructive interference, we have successfully engineered and synthesized a three-dimensional (3D) graphene-based film exhibiting remarkable properties, including metallic thermal conductivity (kappa approximate to 150 Wm-1K-1) and electrical conductivity (sigma approximate to 320 kSm-1) at room temperature. Notably, these films demonstrate colossal transport anisotropies, reaching approximately 103 for thermal and 105 for electrical conductivity. This places them among the conducting materials with the highest anisotropies known to date, surpassing even the performance of one-dimensional (1D) carbon nanotubes and two-dimensional (2D) materials like h-BN and MoS2. These films are synthesized by self-assembly and crosslinking of edge-hydrolyzed graphene flakes. The electron transport between flakes is phonon mediated and at low temperatures the films present quantum critical behavior of a metal to Anderson insulator transition. We measure the electron transport properties in a Hall bar geometry and extract the critical exponents as a function of the sample mobility.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Harnessing the phenomena of quantum coherence and destructive interference, we have successfully engineered and synthesized a three-dimensional (3D) graphene-based film exhibiting remarkable properties, including metallic thermal conductivity (kappa approximate to 150 Wm-1K-1) and electrical conductivity (sigma approximate to 320 kSm-1) at room temperature. Notably, these films demonstrate colossal transport anisotropies, reaching approximately 103 for thermal and 105 for electrical conductivity. This places them among the conducting materials with the highest anisotropies known to date, surpassing even the performance of one-dimensional (1D) carbon nanotubes and two-dimensional (2D) materials like h-BN and MoS2. These films are synthesized by self-assembly and crosslinking of edge-hydrolyzed graphene flakes. The electron transport between flakes is phonon mediated and at low temperatures the films present quantum critical behavior of a metal to Anderson insulator transition. We measure the electron transport properties in a Hall bar geometry and extract the critical exponents as a function of the sample mobility. |
Qiu, Zhizhan; Han, Yixuan; Noori, Keian; Chen, Zhaolong; Kashchenko, Mikhail; Lin, Li; Olsen, Thomas; Li, Jing; Fang, Hanyan; Lyu, Pin; Telychko, Mykola; Gu, Xingyu; Adam, Shaffique; Quek, Su Ying; Rodin, Aleksandr; Neto, Castro A H; Novoselov, Kostya S; Lu, Jiong Evidence for electron-hole crystals in a Mott insulator Journal Article NATURE MATERIALS, 23 (8), 2024, ISSN: 1476-1122. @article{ISI:001237790900002, title = {Evidence for electron-hole crystals in a Mott insulator}, author = {Zhizhan Qiu and Yixuan Han and Keian Noori and Zhaolong Chen and Mikhail Kashchenko and Li Lin and Thomas Olsen and Jing Li and Hanyan Fang and Pin Lyu and Mykola Telychko and Xingyu Gu and Shaffique Adam and Su Ying Quek and Aleksandr Rodin and Castro A H Neto and Kostya S Novoselov and Jiong Lu}, doi = {10.1038/s41563-024-01910-3}, times_cited = {2}, issn = {1476-1122}, year = {2024}, date = {2024-06-03}, journal = {NATURE MATERIALS}, volume = {23}, number = {8}, publisher = {NATURE PORTFOLIO}, address = {HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY}, abstract = {The coexistence of correlated electron and hole crystals enables the realization of quantum excitonic states, capable of hosting counterflow superfluidity and topological orders with long-range quantum entanglement. Here we report evidence for imbalanced electron-hole crystals in a doped Mott insulator, namely, alpha-RuCl3, through gate-tunable non-invasive van der Waals doping from graphene. Real-space imaging via scanning tunnelling microscopy reveals two distinct charge orderings at the lower and upper Hubbard band energies, whose origin is attributed to the correlation-driven honeycomb hole crystal composed of hole-rich Ru sites and rotational-symmetry-breaking paired electron crystal composed of electron-rich Ru-Ru bonds, respectively. Moreover, a gate-induced transition of electron-hole crystals is directly visualized, further corroborating their nature as correlation-driven charge crystals. The realization and atom-resolved visualization of imbalanced electron-hole crystals in a doped Mott insulator opens new doors in the search for correlated bosonic states within strongly correlated materials.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The coexistence of correlated electron and hole crystals enables the realization of quantum excitonic states, capable of hosting counterflow superfluidity and topological orders with long-range quantum entanglement. Here we report evidence for imbalanced electron-hole crystals in a doped Mott insulator, namely, alpha-RuCl3, through gate-tunable non-invasive van der Waals doping from graphene. Real-space imaging via scanning tunnelling microscopy reveals two distinct charge orderings at the lower and upper Hubbard band energies, whose origin is attributed to the correlation-driven honeycomb hole crystal composed of hole-rich Ru sites and rotational-symmetry-breaking paired electron crystal composed of electron-rich Ru-Ru bonds, respectively. Moreover, a gate-induced transition of electron-hole crystals is directly visualized, further corroborating their nature as correlation-driven charge crystals. The realization and atom-resolved visualization of imbalanced electron-hole crystals in a doped Mott insulator opens new doors in the search for correlated bosonic states within strongly correlated materials. |
Negi, Suchit; Carvalho, Alexandra; Neto, Castro A H Theoretical study of defect-mediated ionic transport in Li, Na, and K β and β" aluminas Journal Article PHYSICAL REVIEW B, 109 (13), 2024, ISSN: 2469-9950. @article{ISI:001229669600001, title = {Theoretical study of defect-mediated ionic transport in Li, Na, and K β and β" aluminas}, author = {Suchit Negi and Alexandra Carvalho and Castro A H Neto}, doi = {10.1103/PhysRevB.109.134105}, times_cited = {1}, issn = {2469-9950}, year = {2024}, date = {2024-04-11}, journal = {PHYSICAL REVIEW B}, volume = {109}, number = {13}, publisher = {AMER PHYSICAL SOC}, address = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA}, abstract = {Alkali-metal beta/beta '' aluminas are among the fastest ionic conductors, yet little is understood about the role of defects in the ion transport mechanism. Here, we use density functional theory (DFT) to investigate the crystal structures of the beta and beta '' phases and their vacancy and interstitial defects. We find that charge transport is likely to be dominated by alkali-metal interstitials in beta aluminas and by vacancies in beta '' aluminas. Lower bounds for the activation energy for diffusion are found by determining the minimum-energy paths for defect migration. The resulting migration barriers are lower than the experimental activation energies for conduction in Na beta and beta '' aluminas, suggesting a latent potential for optimization. The lowest activation energy of about 20 meV is predicted for correlated vacancy migration in K beta '' alumina.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Alkali-metal beta/beta '' aluminas are among the fastest ionic conductors, yet little is understood about the role of defects in the ion transport mechanism. Here, we use density functional theory (DFT) to investigate the crystal structures of the beta and beta '' phases and their vacancy and interstitial defects. We find that charge transport is likely to be dominated by alkali-metal interstitials in beta aluminas and by vacancies in beta '' aluminas. Lower bounds for the activation energy for diffusion are found by determining the minimum-energy paths for defect migration. The resulting migration barriers are lower than the experimental activation energies for conduction in Na beta and beta '' aluminas, suggesting a latent potential for optimization. The lowest activation energy of about 20 meV is predicted for correlated vacancy migration in K beta '' alumina. |
Tan, Hui Li; Donato, Katarzyna Z; Costa, Mariana C F; Carvalho, Alexandra; Trushin, Maxim; Ng, Pei Rou; Yau, Xin Hui; Koon, Gavin K W; Tolasz, Jakub; Nemeckova, Zuzana; Ecorchard, Petra; Donato, Ricardo K; Neto, Antonio Castro H Fibrillation of Pristine 2D Materials by 2D-Confined Electrolytes Journal Article ADVANCED FUNCTIONAL MATERIALS, 34 (29), 2024, ISSN: 1616-301X. @article{ISI:001186210500001, title = {Fibrillation of Pristine 2D Materials by 2D-Confined Electrolytes}, author = {Hui Li Tan and Katarzyna Z Donato and Mariana C F Costa and Alexandra Carvalho and Maxim Trushin and Pei Rou Ng and Xin Hui Yau and Gavin K W Koon and Jakub Tolasz and Zuzana Nemeckova and Petra Ecorchard and Ricardo K Donato and Antonio Castro H Neto}, doi = {10.1002/adfm.202315038}, times_cited = {1}, issn = {1616-301X}, year = {2024}, date = {2024-03-18}, journal = {ADVANCED FUNCTIONAL MATERIALS}, volume = {34}, number = {29}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {2D materials are solid microscopic flakes with a-few-Angstrom thickness possessing some of the largest surface-to-volume ratios known. Altering their conformation state from a flat flake to a scroll or fiber offers a synergistic association of properties arising from 2D and 1D nanomaterials. However, a combination of the long-range electrostatic and short-range solvation forces produces an interlayer repulsion that has to be overcome, making scrolling 2D materials without disrupting the pristine structure a challenging task. Herein, a facile method is presented to alter the 2D materials' inter-layer interactions by confining organic salts onto their basal area, forming 2D-confined electrolytes. The confined electrolytes produce local charge inhomogeneities, which can conjugate across the interlayer gap, binding the two surfaces. This allows the 2D-confined electrolytes to behave as polyelectrolytes within a higher dimensional order (2D -> 1D) and form robust nanofibers with distinct electronic properties. The method is not material-specific and the resulting fibers are tightly bound even though the crystal structure of the basal plane remains unaltered.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 2D materials are solid microscopic flakes with a-few-Angstrom thickness possessing some of the largest surface-to-volume ratios known. Altering their conformation state from a flat flake to a scroll or fiber offers a synergistic association of properties arising from 2D and 1D nanomaterials. However, a combination of the long-range electrostatic and short-range solvation forces produces an interlayer repulsion that has to be overcome, making scrolling 2D materials without disrupting the pristine structure a challenging task. Herein, a facile method is presented to alter the 2D materials' inter-layer interactions by confining organic salts onto their basal area, forming 2D-confined electrolytes. The confined electrolytes produce local charge inhomogeneities, which can conjugate across the interlayer gap, binding the two surfaces. This allows the 2D-confined electrolytes to behave as polyelectrolytes within a higher dimensional order (2D -> 1D) and form robust nanofibers with distinct electronic properties. The method is not material-specific and the resulting fibers are tightly bound even though the crystal structure of the basal plane remains unaltered. |
2023 |
Fang, Hanyan; Mahalingam, Harshitra; Li, Xinzhe; Han, Xu; Qiu, Zhizhan; Han, Yixuan; Noori, Keian; Dulal, Dikshant; Chen, Hongfei; Lyu, Pin; Yang, Tianhao; Li, Jing; Su, Chenliang; Chen, Wei; Cai, Yongqing; Neto, Castro A H; Novoselov, Kostya S; Rodin, Aleksandr; Lu, Jiong Atomically precise vacancy-assembled quantum antidots Journal Article 19 NATURE NANOTECHNOLOGY, 18 (12), 2023, ISSN: 1748-3387. @article{ISI:001062548200002, title = {Atomically precise vacancy-assembled quantum antidots}, author = {Hanyan Fang and Harshitra Mahalingam and Xinzhe Li and Xu Han and Zhizhan Qiu and Yixuan Han and Keian Noori and Dikshant Dulal and Hongfei Chen and Pin Lyu and Tianhao Yang and Jing Li and Chenliang Su and Wei Chen and Yongqing Cai and Castro A H Neto and Kostya S Novoselov and Aleksandr Rodin and Jiong Lu}, doi = {10.1038/s41565-023-01495-z}, times_cited = {19}, issn = {1748-3387}, year = {2023}, date = {2023-08-31}, journal = {NATURE NANOTECHNOLOGY}, volume = {18}, number = {12}, publisher = {NATURE PORTFOLIO}, address = {HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY}, abstract = {Patterning antidots, which are regions of potential hills that repel electrons, into well-defined antidot lattices creates fascinating artificial periodic structures, leading to anomalous transport properties and exotic quantum phenomena in two-dimensional systems. Although nanolithography has brought conventional antidots from the semiclassical regime to the quantum regime, achieving precise control over the size of each antidot and its spatial period at the atomic scale has remained challenging. However, attaining such control opens the door to a new paradigm, enabling the creation of quantum antidots with discrete quantum hole states, which, in turn, offer a fertile platform to explore novel quantum phenomena and hot electron dynamics in previously inaccessible regimes. Here we report an atomically precise bottom-up fabrication of a series of atomic-scale quantum antidots through a thermal-induced assembly of a chalcogenide single vacancy in PtTe2. Such quantum antidots consist of highly ordered single-vacancy lattices, spaced by a single Te atom, reaching the ultimate downscaling limit of antidot lattices. Increasing the number of single vacancies in quantum antidots strengthens the cumulative repulsive potential and consequently enhances the collective interference of multiple-pocket scattered quasiparticles inside quantum antidots, creating multilevel quantum hole states with a tunable gap from the telecom to far-infrared regime. Moreover, precisely engineered quantum hole states of quantum antidots are geometry protected and thus survive on oxygen substitutional doping. Therefore, single-vacancy-assembled quantum antidots exhibit unprecedented robustness and property tunability, positioning them as highly promising candidates for advancing quantum information and photocatalysis technologies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Patterning antidots, which are regions of potential hills that repel electrons, into well-defined antidot lattices creates fascinating artificial periodic structures, leading to anomalous transport properties and exotic quantum phenomena in two-dimensional systems. Although nanolithography has brought conventional antidots from the semiclassical regime to the quantum regime, achieving precise control over the size of each antidot and its spatial period at the atomic scale has remained challenging. However, attaining such control opens the door to a new paradigm, enabling the creation of quantum antidots with discrete quantum hole states, which, in turn, offer a fertile platform to explore novel quantum phenomena and hot electron dynamics in previously inaccessible regimes. Here we report an atomically precise bottom-up fabrication of a series of atomic-scale quantum antidots through a thermal-induced assembly of a chalcogenide single vacancy in PtTe2. Such quantum antidots consist of highly ordered single-vacancy lattices, spaced by a single Te atom, reaching the ultimate downscaling limit of antidot lattices. Increasing the number of single vacancies in quantum antidots strengthens the cumulative repulsive potential and consequently enhances the collective interference of multiple-pocket scattered quasiparticles inside quantum antidots, creating multilevel quantum hole states with a tunable gap from the telecom to far-infrared regime. Moreover, precisely engineered quantum hole states of quantum antidots are geometry protected and thus survive on oxygen substitutional doping. Therefore, single-vacancy-assembled quantum antidots exhibit unprecedented robustness and property tunability, positioning them as highly promising candidates for advancing quantum information and photocatalysis technologies. |
Yang, Kou; Hu, Zhitao; Li, Xiaolai; Nikolaev, Konstantin; Hong, Gan Kai; Mamchik, Natalia; Erofeev, Ivan; Mirsaidov, Utkur M; Neto, Antonio Castro H; Blackwood, Daniel J; Shchukin, Dmitry G; Trushin, Maxim; Novoselov, Kostya S; Andreeva, Daria V Graphene oxide-polyamine preprogrammable nanoreactors with sensing capability for corrosion protection of materials Journal Article PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 120 (35), 2023, ISSN: 0027-8424. @article{ISI:001112759000007, title = {Graphene oxide-polyamine preprogrammable nanoreactors with sensing capability for corrosion protection of materials}, author = {Kou Yang and Zhitao Hu and Xiaolai Li and Konstantin Nikolaev and Gan Kai Hong and Natalia Mamchik and Ivan Erofeev and Utkur M Mirsaidov and Antonio Castro H Neto and Daniel J Blackwood and Dmitry G Shchukin and Maxim Trushin and Kostya S Novoselov and Daria V Andreeva}, doi = {10.1073/pnas.2307618120}, times_cited = {3}, issn = {0027-8424}, year = {2023}, date = {2023-08-21}, journal = {PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, volume = {120}, number = {35}, publisher = {NATL ACAD SCIENCES}, address = {2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA}, abstract = {Corrosion is one of the major issues for sustainable manufacturing globally. The annual global cost of corrosion is US$2.5 trillion (approximately 3.4% of the world's GDP). The traditional ways of corrosion protection (such as barriers or inhibiting) are either not very effective (in the case of barrier protection) or excessively expensive (inhibiting). Here, we demonstrate a concept of nanoreactors, which are able to controllably release or adsorb protons or hydroxides directly on corrosion sites, hence, selectively regulating the corrosion reactions. A single nanoreactor comprises a nano compartment wrapped around by a pH-sensing membrane represented, respectively, by a halloysite nanotube and a graphene oxide/polyamine envelope. A nanoreactor response is determined by the change of a signaling pH on a given corrosion site. The nanoreactors are self-assembled and suitable for mass line production. The concept creates sustainable technology for developing smart anticorrosion coatings, which are nontoxic, selective, and inexpensive.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Corrosion is one of the major issues for sustainable manufacturing globally. The annual global cost of corrosion is US$2.5 trillion (approximately 3.4% of the world's GDP). The traditional ways of corrosion protection (such as barriers or inhibiting) are either not very effective (in the case of barrier protection) or excessively expensive (inhibiting). Here, we demonstrate a concept of nanoreactors, which are able to controllably release or adsorb protons or hydroxides directly on corrosion sites, hence, selectively regulating the corrosion reactions. A single nanoreactor comprises a nano compartment wrapped around by a pH-sensing membrane represented, respectively, by a halloysite nanotube and a graphene oxide/polyamine envelope. A nanoreactor response is determined by the change of a signaling pH on a given corrosion site. The nanoreactors are self-assembled and suitable for mass line production. The concept creates sustainable technology for developing smart anticorrosion coatings, which are nontoxic, selective, and inexpensive. |