Hybrid Nanorods Research Articles

Ultrasensitive SERS detection of trinitrotoluene through capillarity-constructed reversible hot spots based on ZnO-Ag nanorod hybrids.

A simple and efficient self-approach strategy was used to apply ultrasensitivity and self-revive ZnO-Ag hybrid surface-enhanced Raman scattering (SERS) sensors for the highly sensitive and selective detection of explosive TNT in both solution and vapour conditions. The good ultrasensitive sensing performance is a result of the abundant Raman hot spots, which were spontaneously formed in a reversible way by the self-approaching of flexible ZnO-Ag hybrid nanorods driven by the capillary force of solvent evaporation. Moreover, the enhancement effect was repeatedly renewed by the reconstruction of molecular bridges, which could selectively detect TNT with a lower limit of 4 × 10(-14) M. In addition, TNT vapor was also tested under this sensor, whereby once the ZnO-Ag NRs hybrid substrate was dipped in TNT, this substrate could detect the existence of TNT even in 5 detection cycles via a capillarity-constructed reversible hot spots approach. Compared with other pure Ag-based SERS sensors, this ZnO-Ag hybrid SERS sensor could rapidly self-revive SERS-activity by simple UV light irradiation and could retain stable SERS sensitivity for one month when used for TNT detection. This stable and ultrasensitive SERS substrate demonstrates a new route to eliminate the oxidized inactive problem of traditional Ag-based SERS substrates and suggests promising use in the applications of such hybrids as real-time online sensors for explosives detection.

Morphology controlled growth of ZnAl-layered double hydroxide and ZnO nanorod hybrid nanostructures by solution method

Morphological evolution of ZnAl-based hybrid nanostructures from ZnAl layered double hydroxide to ZnO nanorods grown by a hydrothermal method depending on the thickness of the Al2O3/ZnO double seed layer.

MnO2 nanoflake/polyaniline nanorod hybrid nanostructures on graphene paper for high-performance flexible supercapacitor electrodes

A facile two-step strategy is adopted to construct a free-standing composite paper of MnO2 nanoflake/polyaniline (PANI) nanorod hybrid nanostructures on reduced graphene oxide (RGO) for flexible supercapacitor electrode application.

Slanted Titanium Dioxide Nano-Rod Based Hybrid Solar Cells.

A slanted columnar titanium dioxide nano-rod was fabricated with the aid of glancing angle deposition and further annealed to change its crystallinity into the anatase phase. The nano-rod hybrid solar cell with 1:0.7 w:w poly-3-hexylthiopene:methanofullerene showed power conversion efficiency of 1.67%.

Facile fabrication of 3D layer-by-layer graphene-gold nanorod hybrid architecture for hydrogen peroxide based electrochemical biosensor

Three-dimensional (3D) layer-by-layer graphene-gold nanorod (GNR) architecture has been constructed. The resulting hybrid nanomaterials’ architecture has been tested for detecting hydrogen peroxide (H2O2) through the electrocatalytic reaction on a three electrode disposable biosensor platform. Cyclic voltammetry and amperometry were used to characterize and assess the performance of the biosensor. The 3D layer-by-layer modified electrode exhibited the highest sensitivity compared to the active carbon, graphene-oxide, cysteine-graphene oxide and GNR coated electrodes. This research explored the feasibility of using the 3D hybrid graphene-GNR as a template for biosensor. The 3D hybrid structure exhibited higher sensitivity than GNRs alone. SEM showed the explanation that GNRs had self-aggregates reducing the contact surface area when coated on the active carbon electrode, while there were no such aggregates in the 3D structure, and TEM illustrated that GNRs dispersed well in the 3D structure. This research demonstrated a better way to prepare well-separated metal nanoparticles by using the 3D layer-by-layer structure. Consequently, other single and bi-metallic metal nanoparticles could be incorporated into such structure. As a practical example, 3D layer-by-layer nanomaterials modified active carbon electrode was used for detecting glucose showing very good sensitivity and minimum interference by ascorbic acid and uric acid in test solution, which indicated a good selectivity of the biosensor as well.

Improved opto-electrical behavior of ZnO/C60 core/shell type organic–inorganic heterostructure

We report a successful synthesis of ZnO/C60 core/shell-type organic–inorganic hybrid nanorod arrays (NRAs) using simple chemical route. X-ray diffraction pattern (XRD) reveals hexagonal crystal structure of ZnO along with the face-centered cubic (fcc) structure of C60. Detailed Fourier transform infrared spectroscopy (FTIR) inferred the attachment of C60 on the surface of ZnO NRAs. HRTEM observation confirmed ∼3nm thickness of a very thin C60 nanocrystals shell layer formation. HRSEM image shows the existence of C60 on vertically aligned ZnO NRAs. UV–visible absorption spectra have two absorption edges corresponding to the energy band gap values of 3.05 and 1.83eV which arise due to core ZnO and shell C60 respectively. Photoluminescence spectra reveal a strong enhancement in the NBE emission and suppression in the deep-level emission on the surface modified ZnO NRAs. The measured electrical resistivity under illumination for ZnO/C60 core/shell is lower than that of bare ZnO NRAs.

The preparation and catalytic property of palladium chloride catalyst supported on organic–inorganic hybrid nanorods

Two novel nano-catalysts with [Pd(dpa)Cl2] moiety have been synthesized by self-assembling organic–inorganic hybrid nanorods from 2,2′-dipyridylamine (dpa). The Pd2+ ions on the surface of the nanorods exhibit high activity for catalyzing Suzuki–Miyaura reactions.

Graphene nanosheets@ZnO nanorods as three-dimensional high efficient counter electrodes for dye sensitized solar cells

Graphene nanosheets@ZnO nanorods as a three-dimensional high efficient counter electrode for dye sensitized solar cells is described, highlighting the ZnO nanorods as a 3D framework nanostructure for preventing the aggregations of GNs. It is demonstrated that, when the nanohybrids are used as CE materials for DSSCs, compared to their pristine GNs, the GNs@ZnO nanorod hybrids without aggregations of GNs have a significant improvement in catalytic performance toward the reduction of triiodide, which were reflected in their electrochemical properties such as high current density, narrow peak-to-peak separation (EPP) and low charge transfer resistance (RCT). The enhancement of electrochemical performance can be attributed to more active defective sites at the edges of GNs and the reduction of the restacking of GNs due to the 3D ZnO nanorod nanostructure. The DSSC with this hybrid CE exhibited energy conversion efficiency (η) of 8.12% with an open circuit voltage (VOC), short circuit photocurrent density (JSC) and fill factor (FF) of 765mV, 21.7mAcm−2, and 67.1%, respectively, which is comparable to that of the conventional Pt CE (8.82%).

Facile formation of Ag2WO4/AgX (X = Cl, Br, I) hybrid nanorods with enhanced visible-light-driven photoelectrochemical properties

In this work, we demonstrated a general strategy for the preparation of a series of uniform Ag2WO4/AgX (X=Cl, Br, I) hybrid nanorods by a facile in-situ anion exchange reaction occurring at room temperature between pregrown Ag2WO4 nanorods and different X− ions in water. Compared with Ag2WO4 nanorods, further investigation has revealed that the as-prepared hybrid nanorods possess significantly enhanced photocurrent response and photocatalytic activity in degrading methyl orange (MO) under visible-light irradiation. In particular, the Ag2WO4/AgBr hybrid nanorods exhibit the highest photocatalytic activity among the three kinds of samples. The active species tests indicate that superoxide anion radicals and photogenerated holes are responsible for the enhanced photocatalytic performance.

One-step in situ synthesis of graphene–TiO2 nanorod hybrid composites with enhanced photocatalytic activity

Chemically bonded graphene/TiO2 nanorod hybrid composites with superior dispersity were synthesized by a one-step in situ hydrothermal method using graphene oxide (GO) and TiO2 (P25) as the starting materials. The as-prepared samples were characterized by XRD, XPS, TEM, FE-SEM, EDX, Raman, N2 adsorption, and UV–vis DRS techniques. Enhanced light absorption and a red shift of absorption edge were observed for the composites in the ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS). Their effective photocatalytic activity was evaluated by the photodegradation of methylene blue under visible light irradiation. An enhancement of photocatalytic performance was observed over graphene/TiO2 nanorod hybrid composite photocatalysts, as 3.7 times larger than that of pristine TiO2 nanorods. This work demonstrated that the synthesis of TiO2 nanorods and simultaneous conversion of GO to graphene “without using reducing agents” had shown to be a rapid, direct and clean approach to fabricate chemically bonded graphene/TiO2 nanorod hybrid composites with enhanced photocatalytic performance.

Erratum to: Novel one-dimensional polyaniline/Ni0.5Zn0.5Fe2O4 hybrid nanostructure: synthesis, magnetic, and electromagnetic wave absorption properties

For the first time, the novel one-dimensional uniform polyaniline (PANI)/Ni0.5Zn0.5Fe2O4 (NZFO) hybrid nanorods were synthesized by an in situ polymerization approach with the assistance of ultrasound and magnetic field. Owing to the unique shape, structure, and chemical composition, the as-synthesized hybrid nanorods with different PANI/NZFO mass ratios possess adjustable magnetic properties, high-saturated magnetization, and coercivity. In addition, these hybrid nanorods present stronger reflection loss and a wider absorption band than pure NZFO. Especially, the hybrid nanorods containing 59 wt% NZFO exhibit excellent microwave absorption properties, with a maximum reflection loss (R L) of −27.5 dB observed at 6.2 GHz. And the widest absorption band (R L ≤ −10 dB) is 8.1 GHz, corresponding to a matching thin thickness of 2 mm. It is superior to the previously reported value of PANI/ferrite. Therefore, these PANI/NZFO hybrid nanorods may be candidates for lightweight, low-cost, broadband, and highly efficient microwave-absorbing materials.

Hybrid electrochromic film based on polyaniline and TiO2 nanorods array

Titanium dioxide (TiO2) nanorods (NRs) array was successfully prepared via hydrothermal method on fluorine doped tinoxide (FTO) coated transparent conductive glass substrate. The hybrid film of polyaniline (PANI)/TiO2 NRs was achieved through electrochemical polymerization of aniline onto the TiO2 NRs array film. The electrochromic and optical properties of the hybrid film were investigated by cyclic voltammetry (CV), amperometric i–t and UV–vis spectroscopy. The results indicate that the hybrid film has long term stability and reversible color changes after cyclic voltammetry scans for 200circles. The PANI/TiO2 NRs hybrid film can show three different colors. Response time of PANI/TiO2 NRs hybrid film is about 0.7s and 2.6s at different states, respectively. The TiO2 NRs array and the loose, porous surface among the hybrid film facilitate charge transmission and also provide large surface area for electrochemical reaction.

A flexible and transparent graphene/ZnO nanorod hybrid structure fabricated by exfoliating a graphite substrate.

We demonstrate the fabrication of a graphene/ZnO nanorod (NR) hybrid structure by mechanical exfoliation of ZnO NRs grown on a graphite substrate. We confirmed the existence of graphene sheets on the hybrid structure by analyzing the Raman spectra and current-voltage (I-V) characteristics. The Raman spectra of the exfoliated graphene/ZnO NR hybrid structure show G and 2D band peaks that are shifted to lower wavenumbers, indicating that the exfoliated graphene layer exists under a significant amount of strain. The I-V characteristics of the graphene/ZnO NR hybrid structure show current flow through the graphene layer, while no current flow is observed on the ZnO NR/polydimethylsiloxane (PDMS) composite without graphene, thereby indicating that the few-layer graphene was successfully transferred onto the hybrid structure. A piezoelectric nanogenerator is demonstrated by using the fabricated graphene/ZnO NR hybrid structure. The nanogenerator exhibits stable output voltage up to 3.04 V with alternating current output characteristics.

Large pulsed electron beam (LPEB)-processed woven carbon fiber/ZnO nanorod/polyester resin composites

Abstract The surface modification of materials by large pulsed electron beam (LPEB) processing is an emerging eco-friendly technique that can be applied to relatively large surface areas. In this study, a polyester-based woven carbon fiber (WCF)/ZnO nanorod hybrid composite was developed using a vacuum-assisted resin transfer molding process. LPEB processing was used to modify the surface of the carbon fiber (CF) composite prior to the growth of the ZnO nanorods. The effects of this electron beam treatment on WCFs were investigated by scanning electron microscopy as a function of ZnO nanorod growth. LPEB treatment resulted in a remarkable increase in the growth of ZnO nanorods. This increase, which resulted in an increase in the electrical resistance of the samples, was further investigated by X-ray diffraction analyses. LPEB-treated samples exhibited higher impact resistance due to strong interactions among the ZnO, CF, and polyester resin.

Novel Hybrid Nanorod Carriers of Fluorescent Hydroxyapatite Shelled with Mesoporous Silica Effective for Drug Delivery and Cell Imaging

Development of biocompatible multifunctional nanocarriers is necessary for the success of theranostics. Here, we report a novel hybrid nanorod with self‐fluorescent property, high drug loading capacity, and good biocompatibility. Fluorescent hydroxyapatite (fHA) nanorod was ensheathed with mesoporous silica (mSi). The mSi shell was uniformly layered and was tunable in thickness (10–30 nm) over the fHA nanorod. Highly mesoporous structure of mSi shell facilitated the loading of a large quantity of biological molecules, as confirmed with fluorescein isothiocynate; ~1% loading for fHA increased to ~10% loading for fHA@mSi. The self‐fluorescent property of the fHA resulting from CO2.− radicals was well preserved in the fHA@mSi hybrid, as analyzed by photoluminescence and electron paramagnetic resonance property. Cellular toxicity of the fHA@mSi hybrid nanorod showed favorable cell viability (>90% viability of control) up to a concentration of ~40 μg/mL. Intracellular uptake rate of the hybrid nanorod was as high as 80–90%, as analyzed by fluorescent‐assisted cell sorter. Results demonstrate the newly developed fHA@mSi nanocarriers have great potential for the effective loading of therapeutic molecules and delivery within intracellular compartments in concert with a capacity for in situ imaging.

Design, synthesis and evaluation of three-dimensional Co3O4/Co3(VO4)2 hybrid nanorods on nickel foam as self-supported electrodes for asymmetric supercapacitors

A novel self-supported electrode of three-dimensional Co3O4/Co3(VO4)2 hybrid nanorods on the conductive substrate of nickel foam have been designed and synthesized by the combination of hydrothermal synthesis and subsequent annealing treatment. Based on the morphology, a possible mechanism is proposed. The unique nanostructure has been served as an “ion reservoir” to infiltrate between the electrode surface area and the electrolyte, which can ensure the ion/electron transfer. And the powerful distribution of electric field on nanorods makes the surface in response the electrode reaction as completely as possible. The electrode manifests satisfying capacitance of 847.2 F g−1, outstanding rate capability and excellent cycling stability. Also, an asymmetric supercapacitor has been assembled, where Co3O4/Co3(VO4)2 and activated carbon acted as the positive and negative electrodes respectively, and the maximum specific capacitance of 105 F g−1 and the specific energy of 38 Wh kg−1 are demonstrated at a cell voltage between 0 and 1.6 V, exhibiting a high energy density and stable power characteristic.

Nanostructured RuO2 on MWCNTs: Efficient catalyst for transfer hydrogenation of carbonyl compounds and aerial oxidation of alcohols

Multiwall carbon nanotubes (MWCNTs)/ruthenium dioxide nanoparticles (RuO2NPs) composite was prepared by a straightforward ‘dry synthesis’ method. After being well characterized, the prepared composite was used as a nanocatalyst (RuO2/MWCNT) for the transfer hydrogenation of carbonyl compounds. The excellent adhesion of RuO2NPs on the anchoring sites of MWCNTs was confirmed by TEM and Raman analyses. The weight percentage (7.97wt%) and the chemical state (+4) of Ru in RuO2/MWCNT was confirmed by EDS and XPS analyses, respectively. It was found that the RuO2/MWCNT has a higher specific surface area of 189.3m2g−1. Initially the reaction conditions were optimized and then the scope of the catalytic system was extended with a wide range of carbonyl compounds. The influence of the size of RuO2NPs on the transfer hydrogenation of carbonyl compounds was also studied. The RuO2/MWCNT is highly chemoselective, heterogeneous in nature, reusable and highly stable. Owing to the high stability of the used catalyst (u-RuO2/MWCNT), it was further calcinated at high temperature to obtain RuO2 nanorods (NRs) hybrid MWCNTs. Then the hybrid material was used as a catalyst (r-RuO2/MWCNT) for the aerial oxidation of alcohols and the result was found to be good.

Light emission from CdSe quantum dot and ZnO nanorod hybrid structures

Light-emitting CdSe quantum dot (QD) — ZnO nanorod (NR) hybrid structures were fabricated via wet chemical methods. Structural investigations indicated that the nano-sized CdSe QDs were formed on the ZnO NRs. Optical investigations showed that the energy band gap of the CdSe QDs was changed by varying the number of deposition cycles of CdSe due to the quantum confinement effect. The emissions from the hybrid structures depended on the existence of an Al2O3 shell layer on the ZnO NRs, which acted as an electrical barrier layer blocking charge carrier losses from the CdSe QDs to the ZnO NRs.

Efficient visible-light photocatalytic activity by band alignment in mesoporous ternary polyoxometalate-Ag2S-CdS semiconductors.

Porous multicomponent semiconductor materials show improved photocatalytic performance due to the large and accessible pore surface area and high charge separation efficiency. Here we report the synthesis of well-ordered porous polyoxometalate (POM)-Ag2S-CdS hybrid mesostructures featuring a controllable composition and high photocatalytic activity via a two-step hard-templating and topotactic ion-exchange chemical process. Ag2S compounds and polyoxometalate cluster anions with different reduction potentials, such as PW12O40(3-), SiW12O40(4-) and PMo12O40(3-), were employed as electron acceptors in these ternary heterojunction photocatalysts. Characterization by small-angle X-ray scattering, X-ray diffraction, transmission electron microscopy and N2 physisorption measurements showed hexagonal arrays of POM-Ag2S-CdS hybrid nanorods with large internal BET surface areas and uniform mesopores. The Keggin structure of the incorporated POM clusters was also verified by elemental X-ray spectroscopy microanalysis, infrared and diffuse-reflectance ultraviolet-visible spectroscopy. These new porous materials were implemented as visible-light-driven photocatalysts, displaying exceptional high activity in aerobic oxidation of various para-substituted benzyl alcohols to the corresponding carbonyl compounds. Our experiments show that the spatial separation of photogenerated electrons and holes at CdS through the potential gradient along the CdS-Ag2S-POM interfaces is responsible for the increased photocatalytic activity.

A hybrid of SnO2 nanorods interlaced by unzipped carbon nanotube to enhance electrochemical properties for lithium ion battery

A hybrid of SnO2 nanorods interlaced by unzipped carbon nanotubes (UCNTs) was synthesized by a simple hydrothermal route. The structure and morphology of the nanocomposites were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N2 adsorption/desorption analysis. Both SEM and TEM images show that SnO2 nanorods were interlaced by UCNTs to form a network structure. The galvanostatic charge–discharge experiments showed that the reversible capacity of the hybrid was improved to 856mAhg−1 at 0.1Ag−1 and kept at 541mAhg−1 after 50 cycles at various current densities, which was higher than that of bare SnO2 nanorods.