Adsorption properties of azobenzene, the prototypical molecular switch, were investigated on a hexagonal boron nitride (h-BN) monolayer ("nanomesh") prepared on Rh(111). The h-BN layer was produced by decomposing borazine (BNH) at 1000-1050 K. Temperature-programmed desorption (TPD) studies revealed that azobenzene molecules adsorbed on the "wire" and "pore" regions desorb at slightly different temperatures. Angle-resolved high-resolution electron energy loss spectroscopy (HREELS) measurements demonstrated that the first molecular layer is characterized predominantly by an adsorption geometry with the molecular plane parallel to the surface. Scanning tunneling microscopy (STM) indicated a clear preference for adsorption in the pores, manifesting a templating effect, but in some cases one-dimensional molecular stripes also form, implying attractive molecule-molecule interaction. Density functional theory (DFT) calculations provided further details regarding the adsorption energetics and bonding and confirmed the experimental findings that the molecules adsorb with the phenyl rings parallel to the surface, preferentially in the pores, and indicated also the presence of an attractive molecule-molecule interaction.
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http://dx.doi.org/10.1021/acs.jpcc.0c01725 | DOI Listing |
ACS Nano
January 2025
Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106319, Taiwan.
Edge contacts offer a significant advantage for enhancing the performance of semiconducting transition metal dichalcogenide (TMDC) devices by interfacing with the metallic contacts on the lateral side, which allows the encapsulation of all of the channel material. However, despite intense research, the fabrication of feasible electrical edge contacts to TMDCs to improve device performance remains a great challenge, as interfacial chemical characterization via conventional methods is lacking. A major bottleneck in explicitly understanding the chemical and electronic properties of the edge contact at the metal-two-dimensional (2D) semiconductor interface is the small cross section when characterizing nominally one-dimensional edge contacts.
View Article and Find Full Text PDFACS Omega
January 2025
Department of Materials Science and Engineering, Gachon University, 1342, Seongnam-daero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, South Korea.
This study investigates the enhancement of polypropylene (PP) composites through the incorporation of exfoliated hexagonal boron nitride (h-BN) nanosheets. The preparation process involved exfoliating h-BN in a liquid phase using a high-pressure homogenizer, followed by the coating of PP pellets with the exfoliated nanosheets using an acoustic mixer. Melt extrusion was then employed to fabricate h-BN-reinforced PP composite films.
View Article and Find Full Text PDFSci Bull (Beijing)
January 2025
Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle Upon Tyne, NE1 8ST, UK.
With the rapid progress of aerospace frontier engineering, the extreme space thermal environment has brought severe challenges to astronauts' space suits, putting forward higher requirements for thermal protection materials. On this basis, a unique core-shell structured hexagonal boron nitride (h-BN)/silicon dioxide (SiO) nanofiber membrane (HS) was prepared using the coaxial electrospinning method, of which both the thermal insulation SiO nanofiber cortex and the passive radiation cooling (PRC) h-BN nanofiber core make it a promising dual-effect thermal management material. Especially, when the amount of h-BN is 0.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Central South University of Forestry and Technology, Shaoshan South Road 498, Changsha 410004, China. Electronic address:
Thermochromic wood-based phase change material (TWPCM) is a temperature-responsive, smart material that actively manages thermal energy in response to ambient temperature fluctuations. The material has become a central focus in research on thermal energy storage and temperature sensing in recent years. A key research direction is the incorporation of delignified veneer impregnated with thermochromic phase change material (TPCM) into a multi-layered structure to enhance the thermal energy storage capacity of TWPCM.
View Article and Find Full Text PDFEnviron 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.
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