Thermal spin transport properties of graphene and hexagonal boron nitride nanoribbon heterojunctions have been investigated using density functional theory calculations combined with the Keldysh nonequilibrium Green's function approach. The results showed that the perfect spin Seebeck effect and analogy negative differential thermoelectric resistance occurred in the device under a temperature difference without a gate or bias voltage. An intriguing thermally induced colossal magnetoresistance without gate regulation was also observed, which can be switched between a positive and negative value with temperature control. It was also found that the unit number of zigzag graphene nanoribbons and boron nitride nanoribbons can tune the electronic band structure and the energy gap of the heterostructure, and then modulate the thermal spin transport properties. The results suggest that graphene and hexagonal boron nitride nanoribbon heterostructures may have potential applications in graphene-based nanodevices.
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http://dx.doi.org/10.1039/c6cp07179a | DOI Listing |
Environ Res
January 2025
Department of Materials Science and Engineering, Xi'an University of Technology, Xi'an 710048, PR China; Shaanxi Province Key Laboratory of Corrosion and Protection, Xi'an University of Technology, Xi'an 710048, PR China. Electronic address:
Hexagonal boron nitride (h-BN) exhibits unique application potential in water purification due to its large specific surface area, high porosity, and chemical inertness. Designing adsorbents with highly active adsorption sites is one effective method to improve their adsorption capacities. In this study, porous h-BN aerogels containing multiple defect types (DP-BN) were synthesized by using salt templates.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Physics, Indian Institute of Science, Bangalore 560012, India.
The low-frequency resistance fluctuations, or noise, in electrical resistance not only set a performance benchmark in devices but also form a sensitive tool to probe nontrivial electronic phases and band structures in solids. Here, we report the measurement of such noise in the electrical resistance in twisted bilayer graphene (tBLG), where the layers are misoriented close to the magic angle (θ ∼ 1°). At high temperatures ( ≳ 60-70 K), the power spectral density (PSD) of the fluctuation inside the low-energy moiré bands is predominantly ∝1/, where is the frequency, being generally lowest close to the magic angle, and can be well-explained within the conventional McWhorter model of the '1/ noise' with trap-assisted density-mobility fluctuations.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Department of Civil and Environmental Engineering, Clarkson University, Potsdam, New York 13699, United States.
The nonthermal destruction of aqueous film-forming foam (AFFF) stockpiles, one of the major culprits responsible for water and soil contamination by per- and polyfluoroalkyl substances (PFAS), is extremely challenging because of the coexistence of mixed recalcitrant PFAS and complicated organic matrices at extremely high concentrations. To date, the complete defluorination of undiluted AFFF at ambient conditions has not been demonstrated. This study reports a novel piezoelectric ball milling approach for treating AFFF with a total organic fluorine concentration of 9080 mg/L and total organic carbon of 234 g/L.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Institute of Soft-matter and Advanced Functional Materials, Gansu Province Carbon New Material Industry Technology Center, School of Materials and Energy, Lanzhou University, Lanzhou 730000, China.
Hexagonal boron nitride (h-BN), with excellent thermal conductivity and insulation capability, has garnered significant attention in the field of electronic thermal management. However, the thermal conductivity of the h-BN-enhanced polymer composite material is far from that expected because of the insurmountable interfacial thermal resistance. In order to realize the high thermal conductivity of polymer composite thermal interface materials, herein, an in situ exfoliation method has been employed to prepare a boron nitride nanosheet-graphene (BNNS-Gr) hybrid filler.
View Article and Find Full Text PDFNat Nanotechnol
January 2025
State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China.
Interfacial ferroelectricity emerges in non-centrosymmetric heterostructures consisting of non-polar van der Waals (vdW) layers. Ferroelectricity with concomitant Coulomb screening can switch topological currents or superconductivity and simulate synaptic response. So far, it has only been realized in bilayer graphene moiré superlattices, posing stringent requirements to constituent materials and twist angles.
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