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One of the critical challenges for semiconductor photocatalysis is the high efficiency utilization of solar energy. For plasmonic metal-semiconductor photocatalysts, the photocatalytic activity over an extended wavelength range for a photoresponsive semiconductor could be significantly improved either via the direct electron transfer (DET) or via the plasmon-induced resonant energy transfer (PIRET). Still, the narrow spectral overlap of plasmon and the semiconductor band edge is a key factor in restricting the development of PIRET. Herein, we have introduced a simple and versatile strategy to realize a broad spectral overlap by creating multipolar plasmon resonances near the semiconductor band edge. Cu2O coated Au/Ag nanorods (NRs) were prepared using a facile wet chemistry method. Transverse plasmon modes of Au/Ag/Cu2O NRs can split into dipole and octupole plasmon modes. The core aspect ratio and shell thickness could be used to regulate these two modes for extending the spectral overlap of plasmon resonance and the Cu2O band edge. Au/Ag/Cu2O NRs were found to display enhanced visible light photocatalytic activity compared to spherical Au/Ag/Cu2O nanoparticles. The enhancement mechanism was ascribed to both dipole and octupole plasmon modes boosting electron-hole separation in Cu2O via PIRET as confirmed by transient absorption measurements.

One of the critical challenges for semiconductor photocatalysis is the high efficiency utilization of solar energy. For plasmonic metal-semiconductor photocatalysts, the photocatalytic activity over an extended wavelength range for a photoresponsive semiconductor could be significantly improved either via the direct electron transfer (DET) or via the plasmon-induced resonant energy transfer (PIRET). Still, the narrow spectral overlap of plasmon and the semiconductor band edge is a key factor in restricting the development of PIRET. Herein, we have introduced a simple and versatile strategy to realize a broad spectral overlap by creating multipolar plasmon resonances near the semiconductor band edge. Cu

In order to meet the growing need for smart bionic devices and epidermal electronic systems, biaxial stretchability is essential for energy storage units. Based on porous single-walled carbon nanotube/poly(3,4-ethylenedioxythiophene) (SWCNT/PEDOT) hybrid fiber, we designed and fabricated a biaxially stretchable supercapacitor, which possesses a unique configuration of the parallel buckled hybrid fiber array. Owing to the reticulate SWCNT film and the improved fabrication technique, the hybrid fiber retained its porous architecture both outwardly and inwardly, manifesting a superior capacity of 215 F g(-1). H3PO4-polyvinyl alcohol gel with an optimized component ratio was introduced as both binder and stretchable electrolyte, which contributed to the regularity and stability of the buckled fiber array. The buckled structure and the quasi one-dimensional character of the fibers endow the supercapacitor with 100% stretchability along all directions. In addition, the supercapacitor exhibited good transparency, as well as excellent electrochemical properties and stability after being stretched 5000 times.

We present the influence of a substrate on the properties of well-dispersed individual ZnO nanorods (NRs) with different diameters, especially on the photoluminescence (PL) properties. The studied ZnO NRs were partially supported by the quartz substrate and partially suspended in air. Continuous redshift and intensity decrease of the near band-edge emission (NBE) were observed along the suspended segment of the ZnO NRs due to the increasing temperature under UV laser excitation, suggesting that the presence of the substrate can effectively enhance the heat-sinking capability of ZnO NRs. Based on the PL measurements on individual suspended ZnO NRs with diameters from 86 nm to 2.35 μm, the redshift of NBE along the suspended segment was more obvious for ZnO NRs with a smaller diameter, indicating that the thermal conductive ability increases as diameter increases. Additionally, by combining the experimental and simulation results, we found that the presence of the substrate also quenched the whispering gallery modes (WGMs) of the ZnO NRs with a diameter above about 350 nm due to the symmetry breaking induced by the quartz substrate which has a larger refractive index compared with air. Our studies confirm that the substrate significantly influences the properties of ZnO NRs. To fully utilize the potential properties of nanomaterials for applications in nanodevices, the substrate-induced effects should be considered thoughtfully.

Hybrid hydro-responsive actuators are developed by infiltrating carbon nanotube yarns using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). These actuators demonstrate impressive rotation and contraction in response to water due to volumetric expansion of the helical arrangement of carbon nanotubes. The total torsional stroke is 3720 revolutions per m and the simultaneously generated contractive strain reaches 24% at a paddle-to-yarn mass ratio of 350. The contraction output can furthermore be significantly enhanced by constraining the rotational motion and it reaches 68% with an applied stress of 1 MPa. Additionally, hybrid yarns exhibit an approximately linear response to humidity changes and show extra capability of electrical actuation, which, combined with the excellent hydro-actuation performance, endow them with great potential for a variety of applications including artificial muscles, hydro-driven generators, moisture switches and microfluidic mixers.

Surfactants or polymers are usually used for the liquid processing of carbon nanotubes for their structure separation. However, they are difficult to remove after separation, affecting the intrinsic properties and applications of the separated species. Here, we report an ethanol-assisted gel chromatography for the chirality separation of single-walled carbon nanotubes (SWCNTs), in which ethanol is employed to finely tune the density/coverage of sodium dodecyl sulfate (SDS) on nanotubes, and thus the interactions between SWCNTs and an allyl dextran-based gel. Incrementally increasing the ethanol content in a low-concentration SDS eluent leads to successive desorption of the different structure SWCNTs adsorbed on the gel, and to achieve multiple distinct (n, m) single-chirality species. The use of ethanol enables the working concentration of SDS to be reduced dramatically and also avoids the introduction of other surfactants or chemical reagents. More importantly, ethanol can be easily removed after separation. The ability of ethanol to tune the interactions between SWCNTs and the gel also gives a deeper insight into the separation mechanism of SWCNTs using gel chromatography.

Ultralong isolated single-walled carbon nanotubes (SWCNTs) were synthesized on a SiO₂/Mo mesh to fabricate long individual suspended SWCNT samples. We detected a delicately temperature dependent Raman RBM, G and G' band frequency shift and linewidth increase of these SWCNTs in the range of 240-600 K. Softening of force constants induced redshift and the mechanism of corresponding spectra linewidth evolution with temperature was analysed and compared with previously reported theories and experimental results. Temperature coefficient differences between G(-) and G(+) were not observed, but the linewidth broadening tendency differences of G(-) and G(+) are obvious. In addition, temperature-dependent G' band evolution, including both frequency red-shifting and FWHM increase has been reported here first. These results will facilitate understanding of the second order Raman scattering process in SWCNTs. Different temperature coefficients measured on suspended and supported parts of the same SWCNT verifies the substrate's influence.

Optical properties of Al2O3 coated individual ZnO nanorods (NRs) with different diameters were studied by confocal micro-photoluminescence spectroscopy. The one-dimensional ZnO/Al2O3 core-shell NRs showed enhanced near band-edge emission compared with the same ZnO NRs before Al2O3 coating at room temperature. Besides, the relative intensity of the deep-level emission with respect to the near band-edge emission was reduced. A model was proposed to explain these spectral changes. For ZnO NRs with diameters above 360 nm, a multi-mode behavior resulting from whispering gallery resonance was observed. In addition, selective enhancement or quenching of different whispering gallery modes in ultraviolet (UV) emission was observed after Al2O3 coating at room temperature, which is due to the larger refractive index of Al2O3 compared with air. We proposed a model to explain these spectral changes as well. By comparing the optical properties before and after surface coating, our results suggest that surface coating of an Al2O3 layer is an effective way to tailor the optical properties of ZnO NRs.

We demonstrate nonvolatile resistive switching in single crystalline ZnO nanowires with high ON/OFF ratios and low threshold voltages. Unlike the mechanism of continuous metal filament formation along grain boundaries in polycrystalline films, the resistive switching in single crystalline ZnO nanowires is speculated to be induced by the formation of a metal island chain on the nanowire surface. Resistive memories based on bottom-up semiconductor nanowires hold potential for next generation ultra-dense nonvolatile memories.

The resistive switching behavior of metal-oxide-metal nanoscale devices is a fascinating phenomenon of next generation nonvolatile memories. Here, we demonstrate nanoscale memristive devices based on Zn(2)SnO(4) nanowires (ZTO NWs) for the first time. The devices show high performance bipolar resistive switching behaviors, including an ultrafast response speed of 20 ns, a low operation voltage of2 V and long data retention (over 5 months). A physical model of metal filament formation along the ZTO NWs has been suggested to explain the bipolar resistive switching behavior.

We develop a facile, effective and filter free infiltration method to fabricate high performance, freestanding and superthin epoxy nanocomposite films with directly synthesized Sing-Walled Carbon Nanotubes (SWNTs) film as reinforcement skeleton. It is found that the thicknesses of the nanocomposite films can be easily controlled in the range of 0.5-3 μm by dripping target amount of acetone diluted epoxy through the skeleton film. The consequent measurements reveal that the mechanical and electrical properties of SWNTs/epoxy nanocomposite films could be tailored in a quite wide range. For examples, the Young's modulus of nanocomposite films can be tuned from 10 to 30 GPa, and the electrical conductivity can be ranged from 1000 S·cm(-1) to be insulated. Moreover, high load transfer efficiency in the nanocomposite films is demonstrated by the measured ultrahigh Raman bands shift rate (-30 ± 5 cm(-1)/% strain) under strain. The high effective modulus is derived as 774 ± 70 GPa for SWNTs inside this nanocomposite film.