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Synthesis of plasmonic Fe/Al nanoparticles in ionic liquids
摘要： Bottom-up and top-down approaches are described for the challenging synthesis of Fe/Al nanoparticles (NPs) in ionic liquids (ILs) under mild conditions. The crystalline phase and morphology of the metal nanoparticles synthesized in three different ionic liquids were identified by powder X-ray diffractometry (PXRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), selected-area electron diffraction (SAED) and fast Fourier transform (FFT) of high-resolution TEM images. Characterization was completed by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) for the analysis of the element composition of the whole sample consisting of the NPs and the amorphous background. The bottom-up approaches resulted in crystalline FeAl NPs on an amorphous background. The top-down approach revealed small NPs and could be identified as Fe4Al13 NPs which in the IL [OPy][NTf2] yield two absorption bands in the green-blue to green spectral region at 475 and 520 nm which give rise to a complementary red color, akin to appropriate Au NPs.
关键词： plasmonic properties,bottom-up synthesis,ionic liquids,Fe/Al nanoparticles,top-down synthesis
更新于2025-09-23 15:21:01
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Bridge between Temperature and Light: Bottom-Up Synthetic Route to Structure-Defined Graphene Quantum Dots as a Temperature Probe In Vitro and in Cells
摘要： Owing to their unique superiorities in chemical and photoluminescence (PL) stability, low toxicity, biocompatibility, and easy functionalization, graphene quantum dots (GQDs) were widely used in cell imaging, probes, and sensors. However, further development and deeper research of GQDs were restricted by their imprecise and complex structure and accompanying controversial PL mechanism. In this work, two kinds of structure defined water-soluble GQDs, with different oxidation degree, were synthesized from molecules by using bottom-up syntheses methods. After studied by a serial of characterizations, their optical properties, functional groups, molecular weight, and structural information were obtained. The optical properties of GQDs could be optimized by controlling their oxidation degree. PL mechanism of GQDs was investigated by comparing their structure and properties. Furthermore, robust, stable, and precise temperature probes were designed by using the GQDs, which exhibited an excellent wide responding range, which covered the whole physiology temperature range, from 0 ℃ to 60 ℃ in water. Moreover, the GQDs were successfully applied as temperature responsive fluorescence probe in Hela cell line. These works put forward a solid foundation for the applications of biological thermo probes and selectively temperature detectors in vitro cellular and in vivo.
关键词： structure controllable,living cell imaging,temperature probe,bottom-up synthesis,mechanism,graphene quantum dots
更新于2025-09-23 15:19:57
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Solution and on-surface synthesis of structurally defined graphene nanoribbons as a new family of semiconductors
摘要： Graphene nanoribbons (GNRs) are quasi-one-dimensional subunits of graphene and have open bandgaps in contrast to the zero-bandgap graphene. The high potential of GNRs as a new family of carbon-based semiconductors, e.g. for nanoelectronic and optoelectronic applications, has boosted the research attempts towards fabrication of GNRs. The predominant top-down methods such as lithographical patterning of graphene and unzipping of carbon nanotubes cannot prevent defect formation. In contrast, bottom-up chemical synthesis, starting from tailor-made molecular precursors, can achieve atomically precise GNRs. In this account, we summarize our recent research progress in the bottom-up synthesis of GNRs through three different methods, namely (1) in solution, (2) on-surface under ultrahigh vacuum (UHV) conditions, and (3) on-surface through chemical vapour deposition (CVD). The solution synthesis allows fabrication of long (>600 nm) and liquid-phase-processable GNRs that can also be functionalized at the edges. On the other hand, the on-surface synthesis under UHV enables formation of zigzag GNRs and in situ visualization of their chemical structures by atomic-resolution scanning probe microscopy. While the on-surface synthesis under UHV is typically costly and has limited scalability, the industrially viable CVD method can allow lower-cost production of large GNR films. We compare the three methods in terms of the affordable GNR structures and the resulting control of their electronic and optical properties together with post-processing for device integration. Further, we provide our views on future perspectives in the field of bottom-up GNRs.
关键词： semiconductors,CVD,on-surface synthesis,UHV,Graphene nanoribbons,optoelectronics,bottom-up synthesis,solution synthesis
更新于2025-09-19 17:15:36
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A Long π-Conjugated Poly-para-Phenylene-Based Polymeric Segment of Single-Walled Carbon Nanotubes
摘要： Conjugated polymers have attracted much attention for many years and have applications in various organic devices. Carbon nanotubes can be considered as all-carbon tube-shaped conjugated polymers containing only sp2-bonded atoms, which play an important role in nanotechnology and nanoelectronics. So far, no study has reported the realization of long π-conjugated polymers as diameter-specified carbon nanotube segments. Herein, we report the first synthesis of a π-conjugated polymeric segment (PS1) of armchair single-walled carbon nanotubes (SWCNTs). PS1 is achieved by a rationally designed synthesis of a bifunctionalized cyclo-para-phenylene monomer, followed by inserting these ring-shaped units into the conjugated poly-para-phenylene backbone. PS1 was fully characterized by gel permeation chromatography (GPC) combined with NMR, FTIR, and Raman spectra. Possessing unique structural and physical properties, this long π-extended polymer PS1 can provide new insight for the development of bottom-up syntheses of uniform carbon nanotube segments and potential applications in electron- and hole-transport devices.
关键词： electron-transport devices,bottom-up synthesis,poly-para-phenylene,carbon nanotubes,π-conjugated polymers,hole-transport devices
更新于2025-09-16 10:30:52