Detonation nanodiamonds (NDs) were deposited on the surface of aligned carbon nanotubes (CNTs) by immersing a CNT array in an aqueous suspension of NDs in dimethylsulfoxide (DMSO). The structure and electronic state of the obtained CNT-ND hybrid material were studied using optical and electron microscopy and Infrared, Raman, X-ray photoelectron and near-edge X-ray absorption fine structure spectroscopy. A non-covalent interaction between NDs and CNT and preservation of vertical orientation of CNTs in the hybrid were revealed. We showed that current-voltage characteristics of the CNT-ND cathode are changed depending on the applied field; below ~3 V/µm they are similar to those of the initial CNT array and at the higher field they are close to the ND behavior. Involvement of the NDs in field emission process resulted in blue luminescence of the hybrid surface at an electric field higher than 3.5 V/µm. Photoluminescence measurements showed that the NDs emit blue-green light, while blue luminescence prevails in the CNT-ND hybrid. The quenching of green luminescence was attributed to a partial removal of oxygen-containing groups from the ND surface as the result of the hybrid synthesis.
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http://dx.doi.org/10.1038/srep09379 | DOI Listing |
Biomed Phys Eng Express
January 2025
Advanced Nuclear Medicine Science, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, JAPAN, Chiba, 263-8555, JAPAN.
For brain-dedicated positron emission tomography (PET) scanners, depth-of-interaction (DOI) information is essential to achieve uniform spatial resolution across the field-of-view (FOV) by minimizing parallax error. Time-of-flight (TOF) information can enhance the image quality. In this study, we proposed a novel monolithic U-shaped crystal design that had a tapered geometry to achieve good coincidence timing resolution (CTR) and DOI resolution simultaneously.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
Crystalline organic semiconductors, recognized for their highly ordered structures and high carrier mobility, have emerged as a focal point in the field of high-performance optoelectronic devices. Nevertheless, the intrinsic unipolar properties, characterized by imbalanced hole and electron transport capabilities, have continuously represented a significant challenge in the advancement of high-performance crystalline thin-film organic light-emitting diodes (C-OLEDs). Here, a bipolar solid-solution thin film with a maintained crystal structure has been fabricated using 2-(4-(9H-carbazol-9-yl)phenyl)-1(3,5-difluorophenyl)-1H-phenanthro [9,10-d]imidazole (2FPPICz) and 4-(1-(3,5-difluorophenyl)-1H-imidazo[4,5-][1,10]phenanthrolin-2-yl)-N,N-diphenylaniline (2Fn) via a weak epitaxial growth (WEG) process, exhibiting nearly equivalent hole and electron mobilities (10-10 cm V s).
View Article and Find Full Text PDFInorg Chem
January 2025
College of Chemistry and Chemical Engineering, Xi'an Shiyou University, Xi'an 710065, China.
Luminescent lanthanide compounds stand out for their distinctive characteristics including narrow emission bands, substantial Stokes shifts, high quantum yields, and unique luminescent colors. However, Ln is highly susceptible to vibrational quenching from X-H (X = O/N) high-energy oscillators in the embedded organic antenna, resulting in significant nonradiative energy dissipation of the D excited states of Ln. Herein, we introduce a strategy based on supramolecular interactions to modulate the nonradiative transitions in a new Zn-Tb heterometallic compound, [ZnTb(HL)(NO)Cl]·2CHCN·HO (), based on a phenyl-substituted pyrazolinone-modified salicylamide-imide ligand ().
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry, Beijing Normal University, Beijing 100875, China.
The deposition of alkali metals on oxide surfaces has garnered significant interest due to their critical role in enhancing various catalytic processes. However, the atomic-scale characterization of these structures remains elusive, owing to the complex and competing interactions among the oxygen, the alkali metals, and the metal atoms within the oxides. In this work, we grew alkali metals (Na, K, Cs) on the copper oxide films on the Cu(111) surface and found the formation of hexagonally ordered monolayer films.
View Article and Find Full Text PDFACS Appl Bio Mater
January 2025
Department of Chemistry, Indian Institute of Technology Palakkad, Palakkad, Kerala 678 623, India.
The aggregation of proteins, peptides and amino acids has been a keen subject of interest owing to their implications in metabolic disorders. In this work, we investigated the self-aggregation of the unmodified aromatic amino acid l-tryptophan (Trp) into unusual spherical microstructures. Using fluorescence spectroscopy and field emission scanning electron microscopy (FE-SEM), we detail the time-dependent transformation of monomeric tryptophan into spherical aggregates with distinct fluorescence characteristics (λ = 345 nm, λ = 430 nm) compared to the monomer.
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