Fluorescence has been observed directly across the band gap of semiconducting carbon nanotubes. We obtained individual nanotubes, each encased in a cylindrical micelle, by ultrasonically agitating an aqueous dispersion of raw single-walled carbon nanotubes in sodium dodecyl sulfate and then centrifuging to remove tube bundles, ropes, and residual catalyst. Aggregation of nanotubes into bundles otherwise quenches the fluorescence through interactions with metallic tubes and substantially broadens the absorption spectra. At pH less than 5, the absorption and emission spectra of individual nanotubes show evidence of band gap-selective protonation of the side walls of the tube. This protonation is readily reversed by treatment with base or ultraviolet light.
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http://dx.doi.org/10.1126/science.1072631 | DOI Listing |
ACS Nano
January 2025
Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, United States.
Most traditional optical biosensors operate through molecular recognition, where ligand binding causes conformational changes that lead to optical perturbations in the emitting motif. Optical sensors developed from single-stranded DNA-functionalized single-walled carbon nanotubes (ssDNA-SWCNTs) have started to make useful contributions to biological research. However, the mechanisms underlying their function have remained poorly understood.
View Article and Find Full Text PDFSmall Methods
January 2025
Nano Hybrid Technology Research Center, Electrical Materials Research Division, Korea Electrotechnology Research Institute (KERI), Changwon, 51543, Republic of Korea.
The conventional carbonization process for synthesizing hard carbons (HCs) requires high-temperature furnace operations exceeding 1000 °C, leading to excessive energy consumption and lengthy processing times, which necessitates the exploration of more efficient synthesis methods. This study demonstrates the rapid preparation of HC anodes using intense pulsed light (IPL)-assisted photothermal carbonization without the prolonged and complex operations typical of traditional carbonization methods. A composite film of microcrystalline cellulose (MCC) and single-walled carbon nanotubes (SWCNTs) is carbonized at high temperatures in less than 1 min.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.
Controlling charge transport at the interfaces of nanostructures is crucial for their successful use in optoelectronic and solar energy applications. Mixed-dimensional heterostructures based on single-walled carbon nanotubes (SWCNTs) and transition metal dichalcogenides (TMDCs) have demonstrated exceptionally long-lived charge-separated states. However, the factors that control the charge transport at these interfaces remain unclear.
View Article and Find Full Text PDFNano Lett
January 2025
Department of Chemical and Biomolecular Engineering, National University of Singapore, 117585, Singapore.
Establishing optimized metal-support interaction (MSI) between active sites and the substrate is essential for modulating the adsorption properties of key reaction intermediates during catalysis, thereby enhancing the catalytic performance. In this study, catalyst composites with varying degrees of MSI are constructed using ruthenium (Ru) and different carbon nanotubes, and their performance for alkaline hydrogen evolution reaction (HER) is systematically investigated. Detailed kinetic assessments reveal that catalysts with a strong MSI exhibit superior HER activity.
View Article and Find Full Text PDFChemistry
January 2025
Henan Normal University, School of Chemistry and Chemical Engineering, CHINA.
Currently, the development of suitable transition metal chalcogenides (TMDs) for aqueous zinc ion batteries (AZIBs) is plagued by the terrible conductivity and electrochemical properties. Herein, a one-step ball milling method is applied to enhance the conductivity of commercial MnTe cathode by constructing three dimensional (3D) carbon nanotubes (CNTs) interweaved MnTe nanoparticles (abbreviated as MnTe@CNTs), which can achieve ultrafast ion conduction. The stable electrochemistry properties benefit from the synergistic effects between layered MnTe and 3D CNTs, which can improve the electrons/ions diffusion kinetics as cycling.
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