Experimental realizations of two-dimensional materials are hardly free of structural defects such as e.g. vacancies, which, in turn, modify drastically its pristine physical defect-free properties. In this work, we explore effects due to point defect clustering on the electronic and transport properties of bilayer graphene nanoribbons, for AA and AB stacking and zigzag and armchair boundaries, by means of the tight-binding approach and scattering matrix formalism. Evident vacancy concentration signatures exhibiting a maximum amplitude and an universality regardless of the system size, stacking and boundary types, in the density of states around the zero-energy level are observed. Our results are explained via the coalescence analysis of the strong sizeable vacancy clustering effect in the system and the breaking of the inversion symmetry at high vacancy densities, demonstrating a similar density of states for two equivalent degrees of concentration disorder, below and above the maximum value.
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http://dx.doi.org/10.1088/1361-6528/ac9f50 | DOI Listing |
Environ Sci Technol
January 2025
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
Pt/CeO single-atom catalysts are attractive materials for CO oxidation but normally show poor activity below 150 °C mainly due to the unicity of the originally symmetric PtO structure. In this work, a highly active and stable Pt/CeO single-site catalyst with only 0.1 wt % Pt loading, achieving a satisfied complete conversion of CO at 150 °C, can be obtained through fabricating asymmetric PtO-oxygen vacancies (O) dual-active sites induced by well-dispersed NbO clusters.
View Article and Find Full Text PDFNat Commun
January 2025
College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, PR China.
Defect engineering can create various vacancy configurations in catalysts by finely tuning the local electronic and geometric structures of the active sites. However, achieving precise control and identification of these defects remains a significant challenge, and the origin of vacancy configurations in catalysts, especially clustered or associated ones, remains largely unknown. Herein, we successfully achieve the controllable fabrication and quantitative identification of triple O-Ti-O vacancy associate (VVV) in nanosized Ni-doped TiO.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
State Key Laboratory of Heavy Oil Processing, Key Laboratory of Optical Detection Technology for Oil and Gas, College of Science, China University of Petroleum, Beijing 102249, PR China.
The purification efficiency of autoexhaust carbon strongly depends on the heterogeneous interface structure between active metal and oxide, which can modulate the local electronic structure of defect sites to promote the activation of reactant molecules. Herein, the high-dispersion CuO clusters supported on the well-defined CeO nanorods were prepared using the complex deposition slow method. The formation of heteroatomic Cu-O-Ce interfacial structural units as active sites can capture electrons to achieve activation of the NO and O molecules.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264000, China.
Constructing multifunctional phosphors grounded in the intricate relationship between energy level structures and luminescent properties has captivated researchers in the luminescent material field. Herein, using the embedded cluster multiconfigurational ab initio method, the energy levels of Bi in the SrLaGaO host at different geometries were calculated, which results in the establishment of complete configurational coordinate curves, yielding breathing mode vibrational frequencies and equilibrium bond lengths for all excited states. These curves supply deep insight into the luminescence properties of Bi-doped phosphors and highlight the impact of ions in the second coordination sphere on luminescence.
View Article and Find Full Text PDFNano Lett
January 2025
Materials Science and Technology Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, Tennessee 37831, United States.
Thermally driven transitions between ferromagnetic and paramagnetic phases are characterized by critical behavior with divergent susceptibilities, long-range correlations, and spin dynamics that can span kHz to GHz scales as the material approaches the critical temperature , but it has proven technically challenging to probe the relevant length and time scales with most conventional measurement techniques. In this study, we employ scanning nitrogen-vacancy center based magnetometry and relaxometry to reveal the critical behavior of a high- ferromagnetic oxide near its Curie temperature. Cluster analysis of the measured temperature-dependent nanoscale magnetic textures points to a 3D universality class with a correlation length that diverges near .
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