One-dimensional Zinc Oxide Research Articles

Enhanced ultraviolet photodetection with Ag nanoparticle-decorated ZnO nanowires and core-shell electrodes

Our study presents the synthesis and characterization of one-dimensional (1-D) zinc oxide (ZnO) nanorod (NR) arrays via low-temperature hydrothermal synthesis, followed by surface modification with silver nanoparticles (Ag NPs). Silver nanowires (AgNWs) are potential alternatives to indium-tin oxide, but their poor stability in atmospheric conditions poses a challenge. To address this, we developed ultrathin Ag/ZnO core-shell structured nanowire networks for ultraviolet-photodetectors (UV-PDs). This cost-effective solution process yielded high transmission (77 %) and low sheet resistance (8.3 Ω/sq). We comprehensively investigated surface morphology, crystalline nature, elemental composition, optical properties, and electrical performance of both synthesized nanorod arrays and NW networks. The UV photodetector exhibited a rise time of approximately 1.35 s and a decay time of 8.01 s, both faster than pristine AgNW electrodes. Additionally, the dark current decreased from 9 nA to 3.5 nA after incorporating Ag/ZnO, accompanied by a significant improvement in photocurrent. These results highlight a promising approach for high-performance UV photodetectors, leveraging the stability and conductivity of Ag/ZnO core-shell NW networks.

Silicon-Based Nanoelectronic Semiconductor Material and Its Surface-Enhanced Raman Image Signals

One-dimensional Zinc Oxide (ZnO) nanomaterials have important applications in devices, such as solar energy, sensors, and piezoelectric materials due to surface effects and quantum size effects. As a semiconductor material, Si has good thermal conductivity and low resistivity. A layer of n-type ZnO nanowires is grown on P-type monocrystalline silicon by transferring the Anodic Aluminum Oxide (AAO) template. The enhanced Raman effect on the surface is attempted by preparing n-type ZnO-P-type Si heterojunction nanostructures. This paper uses Si-based AAO as a template and uses electrochemical deposition method to prepare silicon-based nano-electronic semiconductor material ZnO/AAO/Si. According to SEM analysis, there are uniform pores on the surface of the material, and the cross-section shows that ZnO nanowires have been assembled into the AAO/Si structure. XRD analysis shows that ZnOn nanowires have a hexagonal wurtzite structure. In optoelectronic testing, through PL spectral analysis, the semiconductor material ZnO/AAO/Si has a strong yellow green emission peak near 574 nm. Field emission analysis shows that the β value of the ZnO field enhancement factor in the ZnO/AAO/Si structure is relatively high. The Surface-Enhanced Raman Spectroscopy (SERS) image signal experiment shows that the silicon-based nano-electronic semiconductor material prepared by electrochemical deposition method has good SERS characteristics. The SERS spectral intensity increases with the increase of the concentration of the detected substance and can be used as a SERS substrate to achieve Raman spectral image signal detection of chemical substances with low concentration.

Convergence Gas Sensors with One-Dimensional Nanotubes and Pt Nanoparticles Based on Ultraviolet Photonic Energy for Room-Temperature NO2 Gas Sensing.

Zinc oxide (ZnO) is a promising material for nitrogen dioxide (NO2) gas sensors because of its nontoxicity, low cost, and small size. We fabricated one-dimensional (1D) and zero-dimensional (0D) convergence gas sensors activated via ultraviolet (UV) photonic energy to sense NO2 gas at room temperature. One-dimensional ZnO nanorod (ZNR)-based and ZnO nanotube (ZNT)-based gas sensors were synthesized using a simple hydrothermal method. All the sensors were tested under UV irradiation (365 nm) so that they could be operated at room temperature rather than a high temperature. In addition, we decorated 0D Pt nanoparticles (NPs) on the gas sensors to further improve their sensing responsivity. The NO2-sensing response of the ZNT/Pt NP convergence gas sensor was 2.93 times higher than that of the ZNR gas sensor. We demonstrated the complex effects of UV radiation on 1D ZnO nanostructures and 0D metal nanostructures in NO2 gas sensing.

Three-dimensional rose-like zinc oxide fiber coating for simultaneous extraction of polychlorinated biphenyls and polycyclic aromatic hydrocarbons by headspace solid phase microextraction

The three-dimensional (3D) rose-like zinc oxide (ZnO) material was prepared by a simple one-step CTAB-assisted hydrothermal strategy and used as a headspace solid-phase microextraction (HS-SPME) coating. Polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were analyzed by gas chromatography with flame ionization detector (GC-FID), and conclusively applied to ultrasensitive detection in lake and river water. Compared with one-dimensional (1D) pencil-like ZnO, the layer-by-layer petal-like structure could fully expose mass adsorption sites on the surface, which could significantly improve the adsorption. The enrichment factors with 7535–8595 for PCBs and 3855–7320 for PAHs were achieved. The established method provided a satisfactory linear range (0.005–30 ng·mL−1), coefficient (R2 > 0.9978), ultra-low limit detection (1–3 pg·mL−1), and long service life (≥ 150 times). The recoveries of 83.42–120.86 % were obtained in the real detection application of lake and river water. This work demonstrated that 3D rose-like ZnO with low cost, simple synthesis, fast extraction ability and high enrichment performance was an ideal coating material, which was hoped to enrich other compounds with similar structures with PCBs and PAHs.

From UV to Vis Broadband Photodetectors Based on ZnO/CuO/NiO Core–Shell–Shell Heterojunction Nanostructures

In recent years, with the development of wearable electronics, the demands for high-performance photodetectors with smaller size, lower power consumption, and higher sensitivity have increased remarkably. Photodetectors based on one-dimensional (1D) zinc oxide (ZnO) nanowires (NWs) have been intensively investigated owing to their geometrical nanostructure possessing a large surface-to-volume ratio, high carrier mobility, and adjustable optical absorption. However, ZnO NW photodetectors usually can only detect ultraviolet (UV) light, limiting their application in the field of photodetection. In this paper, a heterojunction photodetector (HPD) based on ZnO/CuO/NiO (ZCN) core–shell–shell NWs is reported. The nanoscale copper oxide (CuO) film is deposited on hydrothermally grown ZnO NWs as the visible light absorber. The nanoscale nickel oxide (NiO) shell layer is uniformly coated on the surface of ZnO/CuO NWs by spin coating, which improves the detection capability of the photodetector in the range of UV-to-visible (UV–vis) significantly. Benefited from the large light absorption area provided by the 1D nanostructure and the type II band alignment, the ZCN NW HPD shows a fast response (rise/decay 0.12/0.22 s) and a large sensitivity of 18.65 mA/W under UV irradiation at a 0 V bias. Experimental and simulation results show the key role of NiO shell layer in ZCN NW HPD. Our results suggest core–shell–shell heterojunction nanostructures to develop high-performance photodetectors for next-generation UV–vis broadband photosensing applications.

Micro spot ZnO nanotubes using laser assisted chemical bath deposition: A low-cost approach to UV photodetector fabrication

Due to its outstanding characteristics across a wide variety of applications, such as electrical, photonic, electrochemical, and electromechanical devices, one-dimensional Zinc oxide (ZnO) is one of the most promising nanostructures. Using a continuous wave semiconductor laser with a wavelength of 460 nm and a power of 1 W, functional ZnO nanostructures known as nanotubes (NTs) with high-quality structural, optical, and electrical properties on a glass substrate coated with iron (Fe) to construct a UV photoconductive detector with high responsivity were produced for first time by using a simple and quick laser assisted chemical bath deposition (LACBD). X-ray diffractometry (XRD), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray (EDX)analyses were used to investigate the evolution of the material's physical and structural characteristics. Our findings revealed that laser-assisted in-situ irradiation of the chemical solution resulted in faster growth of ZnO thin films. To account for the potential of these nanostructures, the effectiveness of ZnO nanotubes (NTs) in ultraviolet (UV) detection has also been investigated. The NT-based photodetector has outstanding stability and responsiveness in both dark and light conditions. Exciton confinement is identified using time-resolved spectroscopy, suggesting that the high surface-to-volume ratio, optical confinement, and high structural quality of the NTs are responsible.

Fabrication of Graphene/Zinc Oxide Nano-Heterostructure for Hydrogen Sensing.

In this study, hydrogen (H2) and methane (CH4) were used as reactive gases, and chemical vapor deposition (CVD) was used to grow single-layer graphene on a copper foil substrate. The single-layer graphene obtained was transferred to a single-crystal silicon substrate by PMMA transfer technology for the subsequent growth of nano zinc oxide. The characteristics of CVD-deposited graphene were analyzed by a Raman spectrometer, an optical microscope, a four-point probe, and an ultraviolet/visible spectrometer. The sol–gel method was applied to prepare the zinc oxide seed layer film with the spin-coating method, with methanol, zinc acetate, and sodium hydroxide as the precursors for growing ZnO nanostructures. On top of the ZnO seed layer, a one-dimensional zinc oxide nanostructure was grown by a hydrothermal method at 95 °C, using a zinc nitrate and hexamethylenetetramine mixture solution. The characteristics of the nano zinc oxide were analyzed by scanning electron microscope(SEM),x-ray diffractometer(XRD), and Raman spectrometer. The obtained graphene/zinc oxide nano-heterostructure sensor has a sensitivity of 1.06 at a sensing temperature of 205 °C and a concentration of hydrogen as low as 5 ppm, with excellent sensing repeatability. The main reason for this is that the zinc oxide nanostructure has a large specific surface area, and many oxygen vacancy defects exist on its surface. In addition, the P–N heterojunction formed between the n-type zinc oxide and the p-type graphene also contributes to hydrogen sensing.

A facile solution processed ZnO@ZnS core–shell nanorods arrays for high-efficiency perovskite solar cells with boosted stability

Zinc Oxide (ZnO) has been extensively applied as electron transport material (ETM) in perovskite solar cells (PSCs) since the emergence of PSCs. However, some chemisorbed oxygen species on the surface of ZnO can cause the degradation of CH3NH3+ (MA+) based perovskite. To avoid the destructive effect of ZnO, a facile solution strategy was proposed to produce a ZnS shell around the ZnO nanorods arrays (ZnO-NRs), i. e. ZnO@ZnS core–shell nanorods (ZnO-NRs@ZnS). The ZnO-NRs@ZnS cascade structure can not only facilitate carrier transport, but also enhance the stability of ZnO based PSCs. A power conversion efficiency (PCE) of 20.6% was finally yielded, which is the-state-of-the-art efficiency for PSCs with one-dimensional (1D) ZnO electron transport materials (ETMs). Moreover, over 90% of the initial efficiency was retained for the unencapsulated device with ZnO-NRs@ZnS ETMs at 85 °C for 500 h, demonstrating excellent stability. This work provides a simple and efficient avenue to simultaneously enhance the photovoltaic (PV) performance and stability of 1D ZnO nanostructure-based PSCs.

Antimicrobial and immunomodulatory potential of nanoscale hierarchical one-dimensional zinc oxide and silicon carbide materials

This work reports the comparison of antimicrobial and immunomodulatory activities between nanoscale hierarchical ZnO nanorods (NRs) and SiC nanowires (NWs). The fabricated one-dimensional (1D) materials possess various nanoscale sizes, morphologies, geometries, and crystal directions. A developed hexamethylenetetramine-assisted hydrothermal regime was followed for preparing wurtzite–ZnO NRs with 40 nm average width, 1 μm length, and [0001] growth orientation. The antibacterial activity of NRs was compared with that of SiC NWs, which had 50–80 nm width and [111] direction. The antibacterial activity of the hierarchical NRs and NWs was tested using different microorganisms including Gram-positive and Gram-negative bacteria and fungi strains. The microbial inactivation of the hierarchical 1D nanomaterials was evaluated by inhibition zone, minimal inhibition concentration (MIC), cell viability assays, and nitroblue tetrazolium reduction test. Cell apoptosis was elucidated by confocal laser scanning microscopy. The scanning electron microscope results showed that [0001]-ZnO NRs led to higher loss in bacterial viability than [111]-SiC NWs. Also, ZnO NRs exhibited lower MIC values than SiC NWs with 3.9, 7.9, 31.25, and 7.91 μg/mL for P. aeruginosa, A. baumannii, S. aureus ATCC 29213, S. typhi ATCC 6539, respectively. This is caused by the higher surface area, smaller width and length, hexagonal wurtzite structure, and highly exposed [0001] polar surface grown along the c-axis of ZnO NRs.

One-dimensional ZnO micro/nanostructures: deep insight into the growth mechanism and fine control of the microscopic morphology.

One-dimensional zinc oxide arrays with various finely controlled microscopic morphologies are grown on fluorine-doped tin oxide substrates by a hydrothermal method. The relationship between the microscopic morphologies and the reaction conditions are studied deeply. It is found that although all the studied reaction parameters, like reaction time, pH value, concentration of the reactants and so on, can affect the microstructures of the resultant products, what they affect, in essence, is the concentration of free Zn2+ ions of the solution. By exploring the evolution of the microstructure of the one-dimensional zinc oxide crystals, it is proved that the formation of the various microscopic morphologies is a result of the competition between the kinetic control and the thermodynamic control during the crystal growth, which in turn is mainly determined by the concentration of the free Zn2+ ions in the solution. The in-depth exploration of the growth mechanism of zinc oxide and the fine control of its microscopic morphologies is expected to provide advanced materials for current and future cutting-edge applications of zinc oxide. It is also expected that the growth mechanism reported here can provide theoretical support for achieving other oxide materials whose microstructure can be finely controlled.

A comparative approach on One-Dimensional ZnO nanowires for morphological and structural properties

Zinc oxide (ZnO) nanowires were grown onto ZnO-seeded substrates by using the chemical bath deposition technique. The deposition time of ZnO seed layers and annealing temperature were varied to investigate their effect on the grown nanowires. The deposition of ZnO seed layers was carried out at 30- and 60-minutes using the radio frequency (RF) magnetron sputter technique. A conventional oven was optimized and compared with a microwave oven to grow ZnO nanowires using the chemical bath deposition (CBD) method. Results revealed that when the deposition time of the ZnO seed layer was increased from 30 to 60 min, the diameter of the grown ZnO nanowires increased from 53.7 to 136.3 nm, respectively. However, no significant change was noticed on the length of the grown ZnO nanowires. Besides, the annealing treatment for the deposited seed layers promoted better ZnO nanowires crystallinity. Interestingly, optimum ZnO nanowires properties were achieved with the ZnO seed layer prepared at a deposited at of 30 min. This work introduced a comparative study on optimizing the preparation approaches and parameters for the growth of well-aligned, high crystallinity ZnO nanowires as a suitable candidate for electrical and optical applications.

Formation and Photoluminescence Properties of ZnO Nanoparticles on Electrospun Nanofibers Produced by Atomic Layer Deposition

The unique combination of optical, chemical, and structural properties of one-dimensional zinc oxide (1D ZnO) makes it one of the most attractive materials in a wide range of research and applications. In the present study, 1D ZnO nanomaterials were fabricated using a combination of two independent methods: electrospinning and atomic layer deposition (ALD). The electrospinning technique was used to produce 1D electrospun fibers consisting of four types of polymers: polylactic acid (PLLA), polyvinylidene fluoride (PVDF), polyvinyl alcohol (PVA), and polyamide 6 (PA6). The ALD technology, in turn, was selected as an excellent candidate for the synthesis of a ZnO thin layer over polymer fibers for the production of 1D ZnO/polymer nanofiber composites (PLLA/ZnO, PVDF/ZnO, PVA/ZnO, PA6/ZnO). Structural and optical properties of the produced nanofibers were studied by means of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), diffuse reflectance, and photoluminescence (PL) spectroscopy. It was found that only PVDF/ZnO nanofibers exhibit stable room temperature PL that may be the result of a higher ZnO content in the sample. In addition, PL measurements were conducted as a function of excitation power and temperature in order to establish the main PL mechanisms and parameters for the PVDF/ZnO sample, as a most promising candidate for the biophotonic application.

Optical dispersion analysis of template assisted 1D-ZnO nanorods for optoelectronic applications

Morphology and size play crucial influential roles in semiconductor nanotechnology. Capping agents have been adopted in this study for controlled fabrication of symmetrical zinc oxide (ZnO) nanostructures, with a preferred orientation and agglomeration inhibition. Elongated one-dimensional (1D) ZnO nanorods were successfully synthesised in a simple two-step process. X-ray diffraction (XRD) revealed high crystalline films with a preferred (002) plane orientation. Ethylene glycol (EG) surfactant was found to produce substantial effect on both the morphology and crystallinity as relatively small uniform nanorods with crocked ends were observed from morphological analysis. All the synthesised ZnO films depicted optical transmittance of over 50% in the visible range and a strong absorption peak in the UV proximity, at 380 nm. An evaluation of the optical parameters calculated from the measured transmittance indicated that surfactants can be used to modify the refractive index, real and imaginary dielectric constants of ZnO nanorods, to optimize the performance of optoelectronic devices.

Organophilicity of Graphene Oxide for Enhanced Wettability of ZnO Nanorods.

Interfacing two-dimensional graphene oxide (GO) platelets with one-dimensional zinc oxide nanorods (ZnO) would create mixed-dimensional heterostructures suitable for modern optoelectronic devices. However, there remains a lack in understanding of interfacial chemistry and wettability in GO-coated ZnO nanorods heterostructures. Here, we propose a hydroxyl-based dissociation-exchange mechanism to understand interfacial interactions responsible for GO adsorption onto ZnO nanorods hydrophobic substrates. The proposed mechanism initiated from mixing GO suspensions with various organics would allow us to overcome the poor wettability (θ ∼ 140.5°) of the superhydrophobic ZnO nanorods to the drop-casted GO. The addition of different classes of organics into the relatively high pH GO suspension with a volumetric ratio of 1:3 (organic-to-GO) is believed to introduce free radicals (-OH and -COOH), which consequently result in enhancing adhesion (chemisorption) between ZnO nanorods and GO platelets. The wettability study shows as high as 75% reduction in the contact angle (θ = 35.5°) when the GO suspension is mixed with alcohols (e.g., ethanol) prior to interfacing with ZnO nanorods. The interfacial chemistry developed here brings forth a scalable tool for designing graphene-coated ZnO heterojunctions for photovoltaics, photocatalysis, biosensors, and UV detectors.

Comprehensive experimental study on production of vertically aligned ZnO nanorod thin films and their electrical, optical and antimicrobial properties

One-dimensional (1D) zinc oxide (ZnO) nanomaterials (e.g. nanorods, nanowires) are the most important due to their electrical and optical properties. As the surface-to-volume ratio in ZnO nanorods (NRs) is very high, the surface states have a crucial role on optical and other properties. So, determination of the production parameters of the ZnO-NRs is important. In this study, a well-aligned ZnO-NRs thin film was produced via the sol–gel and hydrothermal methods. For this purpose, in the first step, a ZnO seed layer was coated onto a cleaned microscope glass slide (sizes of 1.25 × 3.75 cm) by the sol–gel spin coating method. In the second step, ZnO-NRs were grown on the ZnO seed layer by the hydrothermal method. Production parameters for the first step, such as type of the zinc salt; type of the solvent; solution concentration; type of the stabilizer; ageing time process of the solution; spin speed; duration of the spin process; number of repeated coating cycle; heating treatment temperature between coating cycles; duration between coating cycles; final heating treatment temperature and final heating treatment duration of the ZnO seed layer, were obtained. Then similar optimization processes were repeated for the second stage for the ZnO-NRs. The crystal structure, morphological and optical properties of all the produced samples were characterized via X-ray diffraction (XRD) spectroscopy; scanning electron microscopy (SEM); and ultraviolet–visible (UV–Vis) spectroscopy. For comparison, ZnO-NR powders were produced via the mechanochemical solid-state combustion method. The electrical conductivity and optical transparency of the ZnO-NR thin film samples were higher than those of the ZnO-NR powder sample. It was also observed that the well-aligned ZnO-NR thin film sample had a higher bactericidal effect against Bacillus thuringiensis than the ZnO-NR powder sample.

Low-Temperature Vapor-Solid Growth of ZnO Nanowhiskers for Electron Field Emission

One-dimensional zinc oxide nanostructures have aroused interest from scientists and engineers for electron field emission applications because of their experimentally accessible high aspect ratio in combination with their low work function. A comprehensive study of the vapor-solid growth of zinc oxide (ZnO) nanowhiskers by utilizing zinc acetylacetonate hydrate and oxygen at low temperature (580 °C) is reported herein. The nanowhiskers morphology was investigated by varying different growth parameters, such as temperature, substrate type and position, gas flow, precursor amount, and growth time. According to the obtained parameter dependences, the process was optimized to achieve homogenous crystalline nanowhiskers with high aspect ratios and clearly defined surface facets and tips. We show electron field emission measurements from tailor-made ZnO nanowhiskers grown on n-doped silicon, titanium thin films, and free-standing silicon nitride membranes, revealing field emission turn-on fields significantly lower compared to a perfect flat ZnO thin film. Especially the latter devices—ZnO nanowhiskers on a free-standing membrane—might pave the way into a novel nanomembrane detector unit in proteomics, which can significantly extend the mass range of current time-of-flight mass spectrometers.

Omnidirectional light harvesting enhancement of dye-sensitized solar cells decorated with two-dimensional ZnO nanoflowers

In this study, the chemical solution method was used to separately fabricate one-dimensional (1D) zinc oxide (ZnO) nanorods (NRs) and two-dimensional (2D) ZnO nanoflowers (NFs) on photoelectrodes for use in dye-sensitized solar cells (DSSCs). ZnO nanostructures (NSs) with different dimensions were grown on the photoelectrodes, and the effects of the NSs on the omnidirectional light-harvesting characteristics of the DSSCs and their bandgap were evaluated. The crystal structures and morphologies of the ZnO NSs were analysed using X-ray diffraction analysis and field-emission scanning electron microscopy, while their dye-adsorption characteristics were determined using an ultraviolet–visible–near infrared spectrometer. In addition, the finite-difference time-domain method was used to simulate the effects of the dimensions of the NSs on their light-scattering properties. The photoelectrodes with the ZnO NSs with different dimensions were then used to construct DSSCs, which were tested using electrochemical impedance spectroscopy as well as with a monochromatic incident photon-to-electron conversion efficiency measurement system and a solar simulator. Furthermore, with an increase in the incidence angle, the light-conversion efficiency of the 1D ZnO NRs reduced by 63.6% while that of the 2D ZnO NFs reduced only by 12%. Thus, DSSCs based on the 2D ZnO NFs are capable of capturing multidirectional incident light and hence ideal for use under scattered-light conditions.

Influence of Al, Ta Doped ZnO Seed Layer on the Structure, Morphology and Optical Properties of ZnO Nanorods

Background:Zinc oxide (ZnO) is one of the most attractive II-VI semiconductor oxide material, because of its direct wide band gap (3.37 eV) and large binding energy (60 meV). Zinc oxide (ZnO) is a promising semiconductor due to its optimised optical properties. Among semiconductor nanostructures, the vertically aligned one-dimensional ZnO nanorods are very important for nano device application.Methods:Vertically aligned ZnO nanorod arrays were grown on ZnO, aluminum doped ZnO (ZnO:Al), tantalum doped ZnO (ZnO:Ta) and aluminum and tantalum co-doped ZnO (ZnO:Al,Ta) seed layer by hydrothermal method.Results:The X-Ray Diffraction (XRD) investigation indicated the presence of hexagonal phase for the both seed layers and nanorods. The Scanning Electron Microscope (SEM) images of ZnO and doped ZnO seed layer thin-films show spherical shaped nanograins organized into wave like morphology. The optical absorption spectra revealed shift in absorption edge towards the shorter wavelength (blue shifted) for ZnO nanorods grown on ZnO:Al, ZnO:Ta and ZnO:Al,Ta seed layer compared to ZnO nanorods grown on ZnO seed layer.Conclusion:The increase in band gap value for the ZnO nanorods grown on doped ZnO seed layers due to the decrease in crystallite size and lattice constant as evidenced from XRD analysis. The unique property of Al, Ta doped ZnO can be used to fabricate nano-optoelectronic devices and photovoltaic devices, due to their improved optical properties.

AgNi@ZnO nanorods grown on graphene as an anodic catalyst for direct glucose fuel cells

Nano carbon-semiconductor hybrid materials such as graphene and zinc oxide (ZnO) have been vigorously explored for their direct electron transfer properties and high specific surface areas. We fabricated a three-dimensional anodic electrode catalyst nanostructure for a direct glucose fuel cell (DGFC) utilizing two-dimensional monolayer graphene and one-dimensional ZnO nanorods, which accommodate silver/nickel (Ag/Ni) nanoparticle catalyst. Glucose, as an unlimited and safe natural energy resource, has become the most popular fuel for energy storage. Ag and Ni nanoparticles, having superior catalytic activities and anti-poisoning effect, respectively, demonstrate a 73-times enhanced cell performance (550 µW cm−2 or 8 mW mg−1) when deposited on zinc oxide nanorods with a small amount of ∼0.069 mg in 0.5 M of glucose and 1 M of KOH solution at 60 oC. This three-dimensional anodic electrode catalyst nanostructure presents promise to open up a new generation of fuel cells with non-Pt, low mass loading of catalyst, and 3D nanostructure electrodes for high electrochemical performances.

Growth mechanism of novel scaly CNFs@ZnO nanofibers structure and its photoluminescence property

Abstract Zinc oxide (ZnO), a wide direct band gap semiconductor, has attracted extensive attention for its potential optoelectronic applications, such as coherent ultraviolet light emitters. Pure one-dimensional ZnO, structures such as nanorods and nanowires, etc. inevitably have some crystal defects, which makes them to emit not only in the ultraviolet region but also in the visible range. Photoluminescent ZnO‑carbon nanocomposites are an emerging class of nanomaterials that has spurred a lot of interests due to its attractive optical properties. It has been shown that these composite structures yield an enhanced ultraviolet to visible emission ratio due to improved surface plasmon emission and a new defect emission mechanism. Hence, a novel one-dimensional structure of ZnO and carbon nanofibers composite material has been designed and prepared. The scaly ZnO is completely coated with carbon nanofibers. This new composite structure has strong ultraviolet emission photoluminescence characteristics in combination with low visible emission.