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A CdS/reduced graphene oxide (RGO)/ZnO nanowire array (NWAs) heterostructure is designed, which exhibits enhanced photoelectrochemical (PEC) activity compared to pure ZnO, RGO/ZnO, and CdS/ZnO. The enhancement can be attributed to the synergistic effect of the high electron mobility of ordered 1D ZnO NWAs, extended visible-light absorption of CdS nanocrystals, and the formed type II band alignment between them. Moreover, the incorporation of RGO further promotes the charge carrier separation and transfer process due to its excellent charge collection and shuttling characteristics. Subsequently, the CdS/RGO/ZnO heterostructure is successfully utilized for the PEC bioanalysis of glutathione at 0 V (vs Ag/AgCl). The self-powered device demonstrates satisfactory sensing performance with rapid response, a wide detection range from 0.05 mm to 1 mm, an acceptable detection limit of 10 μm, as well as certain selectivity, reproducibility, and stability. Therefore, the CdS/RGO/ZnO heterostructure has opened up a promising channel for the development of PEC biosensors., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We have realized the direct synthesis of ZnO nanorods (ZnO NRs) array on reduced graphene layer (rGO), and demonstrated the enhanced photoelectrochemical (PEC) property of the rGO/ZnO based photoanode under UV irradiation compared with the pristine ZnO NRs array. The introduction of the rGO layer resulted in a favorable energy band structure for electron migration, which finally led to the efficient photoinduced charge separation. Such nanostructure was subsequently employed for self-powered PEC biosensing of glutathione in the condition of 0 V bias, with a linear range from 10 to 200 µM, a detection limit of 2.17 µM, as well as excellent selectivity, reproducibility and stability. The results indicated the rGO/ZnO nanostructure is a competitive candidate in the PEC biosensing field., (Copyright © 2014 Elsevier B.V. All rights reserved.)

In this study, an enzymatic electrochemical biosensor for L-lactate detection was proposed. The device was developed based on gold nanoparticles (Au NPs) modified zinc oxide nanorods (ZnO NRs). The sensing performance of the device was examined by cyclic voltammetry and amperometry. Compared with pristine ZnO based biosensor, Au/ZnO based sensor exhibited higher sensitivity of 24.56 μA cm(-2) mM(-1), smaller K(M)(app) of 1.58 mM, lower detection limit of 6 μM and wider linear range of 10 μM-0.6 mM for L-lactate detection. The introduction of Au NPs enhances electro-catalytic ability and electron migration, which contributes to the improvement of the sensing performance. Hence, the results confirm the essential character of Au NPs in such semiconductor based electrochemical biosensing system., (Copyright © 2015 Elsevier B.V. All rights reserved.)

In this article, Co/Mn-codoped ZnO nanowires (NWs) were successfully synthesized on a silicon substrate by the thermal evaporation method with Au catalyst. The X-ray diffraction pattern indicated that the Co/Mn-codoped ZnO NWs are a hexagonal wurtzite structure without a second phase, and energy dispersive X-ray spectroscopy revealed that the Co and Mn ions were introduced into the ZnO NWs with the content of ∼0.8 at% and ∼1.2 at%, respectively. Photoluminescence spectra and Raman spectra showed that the Co/Mn were doped into the NWs and resulted in the shift of the near-band-edge emission. Moreover, the novel Raman peak at 519.3 cm(-1) has suggested that the two kinds of cations via doping could affect the local polarizability. Compared with the undoped ZnO NW, the electrical measurement showed that the Co/Mn-codoping enhanced the conductivity by an order of magnitude due to the presence of Co, Mn cations. The electron mobility and carrier concentration of a fabricated field effect transistor (FET) device is 679 cm2 V(-1) s(-1) and 2×10(18) cm(-3), respectively. Furthermore, the M-H curve demonstrated that the Co/Mn-codoped ZnO NWs have obvious ferromagnetic characteristics at room temperature. Our study enhances the understanding of the novel performances of transition-metal codoped ZnO NWs and also provides a potential way to fabricate optoelectronic devices.

The transport properties of Cu/ZnO-nanobelt/Cu nanostructures under uniaxial strains were studied using first-principles calculations, with emphasis on the interfacial contacts. The conductivity G is very sensitive to strain, and it decreases linearly when strain varied from compression to tension, and the piezoresistive gauge factors (GFs) of ZnO nanobelts in non-polarized direction are 5.66 and 4.29 for compressive ( [ABSTRACT FROM AUTHOR]

Nowadays, the fabrication of photoanodes with high light-harvesting capability and charge transfer efficiency is a key challenge for photoelectrochemical (PEC) water splitting. In this paper, large-scale patterned ZnO nanorod arrays (NRAs) were designed and fabricated via two-beam laser interference lithography and hydrothermal synthesis, which were further applied as PEC photoanodes for the first time. By adopting the ZnO NRA photoanodes with square pattern, the PEC cells achieved a maximum efficiency of 0.18%, which was improved 135% compared to the control group with no patterned ZnO NRAs. The large-scale highly ordered ZnO NRAs have enhanced light-harvesting ability due to the light-scattering effect. In addition, the enlarged surface area of the patterned ZnO NRAs accelerated the charge transfer at the photoanode/electrolyte interface. This research demonstrates an effective mean to realize the efficient solar water splitting, and the results suggest that large-scale highly ordered nanostructures are promising candidates in the field of energy harvesting. [ABSTRACT FROM AUTHOR]

Abstract: The one-dimensional (1D) Zn1−x Ni x O (x =0, 0.02, 0.05, 0.10) nanorods have been synthesized by a simple hydrothermal method. New bands show at ∼130cm−1 in the Raman spectra of Ni-doped ZnO nanorods and their relative intensity depends on the doping concentration of nickel. The optical band gap of the ZnO nanorods have been tuned by Ni-doping, which is revealed by absorption spectra. The photocatalytic activity of Zn1−x Ni x O was studied by comparing the degradation rate of rhodamine B (RB) under UV-light irradiation. It was found that Zn0.95Ni0.05O exhibited the highest photocatalytic degradation efficiency among the samples. [Copyright &y& Elsevier]

Abstract: Li-doped p-type ZnO thin films were grown by using radio frequency magnetron sputtering. In our experiment, ZnO targets were fabricated by using the Li-doped ZnO powders that had been synthesized by glycine (urea)–nitrate combustion process. The structural characteristics of ZnO thin films were examined by XRD and SEM. The results showed that ZnO films possess a good crystalline with c-axis orientation, uniform thickness and dense surface. Current–voltage properties of p-ZnO:Li/n-Si structure had been examined in an effort to delineate the carrier type behavior in ZnO semiconductor. p-ZnO:Li/n-Si heterojunctions displayed rectifying behavior. As a result I–V measurements exhibited a polarity consistent with the Li-doped ZnO being p-type. [Copyright &y& Elsevier]

Abstract: High quality ZnO comb-like nanostructures have been fabricated in high yields through oxidative evaporation of pure zinc powder without catalyst at 600–650°C. SEM, FE-SEM and HRTEM observations showed that the resulting ZnO nanostructures have two main types of single crystal morphology. Investigations through HRTEM and XRD revealed that the growth of the synthesized ZnO nanostructures was controlled by a vapor–solid (VS) mechanism. Room temperature photoluminescence (PL) spectra of the nanocombs showed a UV emission at ∼385nm and a broad green emission at ∼495nm. Such novel structures are promising for applications in some special fields. [Copyright &y& Elsevier]