C60 Nanorods Research Articles

Rubrene-Directed Structural Transformation of Fullerene (C60) Microsheets to Nanorod Arrays with Enhanced Photoelectrochemical Properties

One-dimensional (1D) nanostructures possess huge potential in electronics and optoelectronics, but the axial alignment of such 1D structures is still a challenging task. Herein, we report a simple method that enables two-dimensional (2D) C60 microsheets to evolve into highly ordered nanorod arrays using rubrene as a structure-directing agent. The structural transformation is accomplished by adding droplets of rubrene-m-xylene solution onto C60 microsheets and allowing the m-xylene solvent to evaporate naturally. In sharp contrast, when rubrene is absent from m-xylene, randomly oriented C60 nanorods are produced. Spectroscopic and microscopic characterizations collectively indicate a rather plausible transformation mechanism that the close lattice match allows the epitaxial growth of rubrene on C60 microsheets, followed by the reassembly of dissolved C60 along the aligned rubrene due to the intermolecular charge-transfer (CT) interactions, leading to the formation of ordered nanorod arrays. Due to the aligned structures and the CT interactions between rubrene and C60, the photocurrent density of the nanorod arrays is improved by 31.2% in the UV region relative to the randomly oriented counterpart. This work presents a facile and effective strategy for the construction of ordered fullerene nanorod arrays, providing new ideas for the alignment of fullerene and other relevant organic microstructures.

C60 nanorods as a promising infrared nonlinear optical material for ultrafast photonics

As a typical one dimensional (1D) crystals, C60 nanorods has attracted widely attention in ultrafast optical field due to its excellent photoelectric properties, including broadened and extended optical absorption, high photosensitivity as well as photogenerated charge carriers mobility. Here, C60 nanorods are synthesized by a liquid-liquid interfacial precipitation method of m-xylene and isopropyl alcohol (IPA) solution. By tuning the solvent amount ratio, a hexagonal close-packed polycrystalline nanorod structure with a broadband absorbance spectrum is achieved. Its’ nonlinear optical absorption characteristics are studied through a balanced twin-detector measurement system. Experimental results show that C60 nanorods has excellent nonlinear absorption with a high modulation depth of ∼16% and a low nonsaturable absorption of ∼4%. Besides, a high optical-to-optical slope efficiency of 7.8% mode-locking all fiber laser is achieved in the optical communication region. The C60 nanorods has great prospect on high effective fiber laser mode locking and open a new way for the development of ultrafast optical devices.

Synergetic effect of C60/g‐C3N4 nanowire composites for enhanced photocatalytic H2 evolution under visible light irradiation

AbstractC60 functioned g‐C3N4 nanocomposites were prepared by calcining the mixture of urea and C60 nanorods formed via a liquid‐liquid interfacial precipitation method. The obtained C60/g‐C3N4 nanowire composites exhibit better utilization of solar energy, efficient transfer and separation of photoinduced charge carriers. The optimum photocatalytic H2 evolution rate for C60/g‐C3N4‐0.03 wt % containing 0.03 wt % C60 under visible light irradiation reaches 8.73 μmol/h (with quantum efficiency of 5.10 %), which is about 4.7 times as high as that of pure g‐C3N4. This remarkable enhanced photocatalytic performance of C60/g‐C3N4‐0.03 wt % is mainly attributed to the synergistic effect of the interface formed between g‐C3N4 and C60 nanorods.

Facile preparation of fullerene nanorods for high-performance lithium-sulfur batteries

Lithium-sulfur batteries have been considered as one of the most promising electrochemical power sources due to its extremely high energy density and high theoretical specific capacity. However, poor cycling life due to the dissolution of lithium polysulfides hinders its practical application. In this paper, C60 nanorods are prepared by a facile, scalable and repeatable antisolvent induced precipitation method at an ambient temperature and used as a novel interlayer material for lithium-sulfur batteries. It was proved that C60 nanorods could efficiently inhibit the diffusion of lithium polysulfides via both physical adsorption and strong chemical bonding. Lithium-sulfur batteries with C60 interlayer delivered a capacity of 725 mAh g−1 and a capacity retention of 154.5% after 500 cycles at 4800 mAg−1 with a coulombic efficiency around 100%.

Quantum Dot Modified One-Dimensional C60 Nanorod in Situ Preparation and Photoinduced Charge Transfer

CdSe/CdS/ZnS quantum dot (QD) modified C60 nanorods were performed by the liquid–liquid interfacial precipitation method. Transmission electron microscopy and scanning electron microscopy were used to characterize the hybrid C60 structure and found that the CdSe/CdS/ZnS QDs were attached on the surface of C60 nanorods. UV–vis absorption spectroscopy, surface photovoltage spectroscopy (SPS), and steady-state and transient spectra photoluminescence (PL) were used to investigate the nanorods’ optoelectronic properties. The CdSe/CdS/ZnS QD PL quench, decreasing lifetime, and enhanced SPS response were observed for the hybrid QDs/C60 nanorod films. The charge transport property of a single C60 nanorod modified by CdSe/CdS/ZnS QDs was also investigated for photocurrent occurrence. It is considered that the photoinduced charge transfers from CdSe/CdS/ZnS QDs to C60 nanorods by tunneling through the oleylamine ligand. The hybrid QDs/C60 nanorod will be a good system for adjusting the interaction and the ability of charge transportation between the QDs and C60 by ligand exchange. The in situ preparation method for the hybrid QD/C60 nanorod films has high yield at room temperature.

Optoelectronic properties of one-dimensional fullerene Nanorods

One-dimensional (1D) C60 nanorods were synthesized using a liquid-liquid interfacial precipitation method. TEM and SEM were used to characterize the C60 structure. The C60 nanorod growth direction was mainly limited to the [110] direction. Surface photovoltage spectroscopy (SPS) was used to study the optoelectronic property of 1D C60 nanorods film, and greatly enhanced SPS response was observed compared with the pristine C60 film, indicating that the 1D structure of the C60 nanorods is beneficial for the separation and transport of photo-generated charges. The charge transport property of a single C60 nanorod assembled on Au electrodes was also investigated, and it was found that its I-V curve exhibits special rectifying behavior.

One-step synthesis of C60 nano-assemblies at different temperatures

Nanoassemblies (microtubes, microrods, nanoflowers and nanorod arrays) composed of C60 nanorods, were fabricated with a solution evaporation method. The structures and the growth mechanism of C60 nano-assemblies were investigated. The C60 microtubes obtained at room temperature had a hexagonal structure, C60 microrods and nanoflowers synthesized at 0°C and −15°C had a similar mixed hexagonal structure, and the C60 nanorod arrays had a structure indexed as an orthorhombic structure. The morphology of the C60 nano-assemblies depended on the shape and size of the seed crystals, which were closely related to the precipitation process from the saturated solution at different temperatures.

Unusual thermal transport behavior in self-assembled fullerene nanorods

Ultralow thermal conductivity (less than 0.06 W m−1 K−1) is observed for self-assembled C60 nanorods at room temperature.

Demonstration of ultrarapid interfacial formation of 1D fullerene nanorods with photovoltaic properties.

We demonstrate ultrarapid interfacial formation of one-dimensional (1D) single-crystalline fullerene C60 nanorods at room temperature in 5 s. The nanorods of ∼ 11 μm in length and ∼ 215 nm in diameter are developed in a hexagonal close-pack crystal structure, contrary to the cubic crystal structure of pristine C60. Vibrational and electronic spectroscopy provide strong evidence that the nanorods are a van der Waals solid, as evidenced from the preservation of the electronic structure of the C60 molecules within the rods. Steady state optical spectroscopy reveals a dominance of charge transfer excitonic transitions in the nanorods. A significant enhancement of photogenerated charge carriers is observed in the nanorods in comparison to pristine C60, revealing the effect of shape on the photovoltaic properties. Due to their ultrarapid, large-scale, room-temperature synthesis with single-crystalline structure and excellent optoelectronic properties, the nanorods are expected to be promising for photosensitive devices applications.

Ultrahigh performance C60 nanorod large area flexible photoconductor devices via ultralow organic and inorganic photodoping.

One dimensional single-crystal nanorods of C60 possess unique optoelectronic properties including high electron mobility, high photosensitivity and an excellent electron accepting nature. In addition, their rapid large scale synthesis at room temperature makes these organic semiconducting nanorods highly attractive for advanced optoelectronic device applications. Here, we report low-cost large-area flexible photoconductor devices fabricated using C60 nanorods. We demonstrate that the photosensitivity of the C60 nanorods can be enhanced ~400-fold via an ultralow photodoping mechanism. The photodoped devices offer broadband UV-vis-NIR spectral tuneability, exhibit a detectivitiy >109 Jones, an external quantum efficiency of ~100%, a linear dynamic range of 80 dB, a rise time 60 µs and the ability to measure ac signals up to ~250 kHz. These figures of merit combined are among the highest reported for one dimensional organic and inorganic large-area planar photoconductors and are competitive with commercially available inorganic photoconductors and photoconductive cells. With the additional processing benefits providing compatibility with large-area flexible platforms, these devices represent significant advances and make C60 nanorods a promising candidate for advanced photodetector technologies.

Palladium nanocrystals supported on photo-transformed C60 nanorods: Effect of crystal morphology and electron mobility on the electrocatalytic activity towards ethanol oxidation

We report on the synthesis and decoration of high-aspect-ratio crystalline C60 nanorods (NRs) by functionalized palladium nanoparticles with an average size of 4.78±0.66nm. In their pristine form, C60 NRs suffer from partial damage in the solution-based decoration process resulting in poor crystallinity. However, by modifying the NR surface via in situ photochemical transformation in the liquid state, we are able to prepare highly stable NRs that retain their crystalline structure during the decoration process. Our method thus opens up for the synthesis of highly crystalline nanocomposite hybrids comprising Pd nanoparticles and C60 NRs. Bys measuring the electron mobility of different C60 NRs, we relate both the effect of electron mobility and crystallinity to the final electrocatalytic performance of the synthesized hybrid structures. We show that the photo-transformed C60 NRs exhibit highly advantageous properties for ethanol oxidation based on both a better crystallinity and a higher bulk conductivity. These findings give important information in the search for efficient catalyst support.

Solution-Based Phototransformation of C60 Nanorods: Towards Improved Electronic Devices

A modified liquid–liquid interface precipitation synthesis of C60 nanorods, effects and opportunities following an in situ photochemical transformation in the liquid state, and an electronic characterization using a field-effect transistor (FET) geometry are reported. The nanorods feature a high aspect ratio of ≈103 and a notably small average diameter of 172 nm. Interestingly, it is found that a decreased nanorod diameter appears to correlate with distinctly improved electronic properties, and an average electron mobility of 0.30 cm2 V−1 s−1, as measured in a FET geometry, is reported for as-grown nanorods, with the peak value being an impressive 1.0 cm2 V−1 s−1. A photoexposure using green laser light (λ = 532 nm) is demonstrated to result in the formation of a polymer-C60 shell encapsulating a monomer-C60 bulk; such photo-transformed nanorods exhibit an electron mobility of 4.7 × 10−3 cm2 V−1 s−1. It is notable that the utilized FET geometry only probes the polymer-C60 nanorod surface shell, and that the monomer-C60 bulk is anticipated to exhibit a higher mobility. Importantly, photoexposed nanorods can be conveniently processed as a stabile dispersion in common hydrophobic solvents, and this finding is attributed to the insoluble character of the polymer-C60 shell.

On the fabrication of crystalline C60 nanorod transistors from solution

Flexible and high-aspect-ratio C60 nanorods are synthesized using a liquid–liquid interfacial precipitation process. As-grown nanorods are shown to exhibit a hexagonal close-packed single-crystal structure, with m-dichlorobenzene solvent molecules incorporated into the crystalline structure in a C60:m-dichlorobenzene ratio of 3:2. An annealing step at 200 °C transforms the nanorods into a solvent-free face-centred-cubic polycrystalline structure. The nanorods are deposited onto field-effect transistor structures using two solvent-based techniques: drop-casting and dip-coating. We find that dip-coating deposition results in a preferred alignment of non-bundled nanorods and a satisfying transistor performance. The latter is quantified by the attainment of an electron mobility of 0.08 cm 2 V −1 s −1 and an on/off ratio of > 104 for a single-crystal nanorod transistor, fabricated with a solution-based and low-temperature process that is compatible with flexible substrates.

Water Assisted Growth of C60 Rods and Tubes by Liquid–Liquid Interfacial Precipitation Method

C60 nanorods with hexagonal cross sections are grown using a static liquid–liquid interfacial precipitation method in a system of C60/m-dichlorobenzene solution and ethanol. Adding water to the ethanol phase leads instead to C60 tubes where both length and diameter of the C60 tubes can be controlled by the water content in the ethanol. Based on our observations we find that the diameter of the rods/tubes strongly depends on the nucleation step. We propose a liquid-liquid interface growth model of C60 rods and tubes based on the diffusion rate of the good C60 containing solvent into the poor solvent as well as on the size of the crystal seeds formed at the interface between the two solvents. The grown rods and tubes exhibit a hexagonal solvate crystal structure with m-dichlorobenzene solvent molecules incorporated into the crystal structure, independent of the water content. An annealing step at 200 °C at a pressure <1 kPa transforms the grown structures into a solvent-free face centered cubic structure. Both the hexagonal and the face centered cubic structures are very stable and neither morphology nor structure shows any signs of degradation after three months of storage.

Laser beam deflectometry and C60 polymerized nanorods dynamics by surface interdiffusion

Laser beam deflectometry was used to follow the growth dynamic of C60 nanorods via an interfacial diffusion and self-assembly phenomenon. The deduced average value of the interfacial diffusion coefficient Dint from the refractive index gradient was found to be of the order of 3.32 10−6m2/s.

Decoration of C60 nanorods with nickel and their magnetic properties

We studied the coating of C60 nanorods with nickel by electroless plating method and investigated their magnetic properties. The morphology and structure of the nickel layer coated on C60 nanorods were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Raman spectroscopy. The coated nickel is in the form of nano-sized crystals and becomes a continuous layer as reaction time increases. The hysteresis loop shows a super paramagnetic characteristic similar to that of nanometer-sized nickel particle. These results suggest that the average size of nickel particles on C60 rods is below 10 nm. Our study has shown that electroless plating is an efficient and simple method for coating C60 nanorods with nickel.

Photoluminescence properties of high-pressure-polymerized C60 nanorods in the orthorhombic and tetragonal phases

C 60 nanorods in two polymeric phases have been synthesized under different high pressure and high temperature conditions. Orthorhombic and tetragonal phases have been identified from Raman spectra. The rod shape can be kept under quasihydrostatic pressure. The photoluminescence intensity of the polymeric C60 nanorods has been greatly enhanced compared with that of pristine C60 nanorods. The main fluorescence band shifted from 730nm in the unpolymeric phase to 748nm and near infrared 780nm in the orthorhombic and tetragonal phases, respectively. The enhanced photoluminescence with tunable frequency for different polymeric C60 nanorods suggests potential applications in luminescent nanomaterials.

Synthesis of Thin, Rectangular C60 Nanorods Using m‐Xylene as a Shape Controller

Thin, rectangular C60 nanorods in face-centered cubic structure are synthesized by using m-xylene as a shape controller. These unusual nanorods can easily grow on various substrates. The smallest n ...

High Pressure and High Temperature Induced Polymeric C60 Nanorods and Their Photoluminescence Properties

AbstractWe report that C60 nanorods of three polymeric phases have been synthesized under high pressure and high temperature and that the photoluminescence properties of these polymeric nanorods also have been studied. C60 nanorods were fabricated by a facile solution evaporation method. Raman spectra indicate that this material transformed into orthorhombic, tetragonal and rhombohedral polymeric phases under various high pressure and high temperature conditions. SEM measurements show that the shape of the nanorods can be kept under quasi-hydrostatic pressure condition. The photoluminescence intensity of the polymeric C60 nanorods has been enhanced compared with that of the pristine C60 nanorods. The main fluorescence band shifted from 1.70 eV in the monomeric phase to near infrared in the polymeric phase when pressure and temperature were increased. The enhanced fluorescence with adjustable frequency for different polymeric C60 nanorods makes possible potential application in luminescent nanomaterials.

A Facile Solution Method to Synthesis of C60 Nanorods

ABSTRACTWe report here a facile solution method to synthesis of C60 nanorods. A very simple and effective solvent, neat m-xylene, from which C60 can rapidly grow into individual novel nanorods with widths and thicknesses of the order of nanometers was found as a shape controller. These unusual nanorods can easily grow on various substrates such as glass and silicon, and nanorods with different diameters and length-to-diameter ratios can be synthesized under different growth conditions. The smallest nanorods we obtained have widths smaller than 30 nm. The nanorods obtained are highly crystalline and single phase.