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In this study, we demonstrate for the first time the construction of a ternary BiVO4/FeVO4/Cu2O nanorod array (NRA) photoelectrode via seed-assisted refluxing, hydrothermal and successive ionic-layer adsorption and reaction (SILAR) method and its photoelectrochemical (PEC) water oxidation performance. The energy band structures of the BiVO4, FeVO4 and Cu2O show that two type-II band alignments with a ladder-like structure are formed in the constructed ternary BiVO4/FeVO4/Cu2O NRA photoelectrode, enabling the photoelectrode to display substantially enhanced PEC performance. The constructed ternary photoelectrode loaded with the optimized Cu2O nanoparticles achieves a zero-bias photocurrent density of 50 μA cm−2, 5 times higher than that of the pure BiVO4 NRA photoelectrode. The measurements of optical property reveal that the constructed BiVO4/FeVO4/Cu2O nanorod arrays (NRAs) demonstrate improved light absorption capability. The electrochemical impedance and photoluminescence measurements confirm that the charge carriers of the BiVO4/FeVO4/Cu2O heterojunction NRAs are transferred and separated effectively. The substantially boosted PEC water oxidation activity of the constructed ternary BiVO4/FeVO4/Cu2O heterojunction NRA photoelectrode is ascribed to the improved light harvesting and effective charge separation.

We report for the first time that nonmetal plasmonic TiN nanoparticles act as hot-electron booster to remarkably enhance photocurrent and hydrogen production of CdS nanoroad arrays (NRAs) via a photoelectrochemical cell. The optimized TiN–CdS NRAs produce a bias-free photocurrent of 2.9 mA cm−2. Furthermore, the highest photoconversion efficiency of the TiN–CdS nanorod array (NRA) photoanode with optimized loading of the TiN NPs is up to 2.2%, 1.6-fold that of the pristine CdS NRA photoanode (1.4%) at 0.22 V versus RHE. Most importantly, TiN–CdS NRAs achieve a hydrogen production rate of 101.5 μmol h−1 cm−2, about 2 times higher than that of the CdS NRAs. Experimental evidences of the photoluminescence emission apparently confirm that hot-electron injection from TiN to CdS plays a crucial role for enhancing photocurrent and hydrogen production. This work demonstrates that nonmetal plasmonic TiN can be integrated into new platforms for efficient solar energy conversion.

Herein, both plasmonic sensitizer and electron relay are integrated into ZnO/Au/CdS sandwich nanotube array (NTA) to construct a novel photoanode for efficient solar-to-hydrogen conversion via photoelectrochemical (PEC) cell. Under bias-free simulated solar light illumination, a photocurrent of the ZnO/Au/CdS sandwich NTA photoanode is up to 6.5 mA/cm2, 24 times that of ZnO, and 14 times that of ZnO/Au NTA photoanodes, respectively. Furthermore, the highest solar-to-hydrogen efficiency of the ZnO/Au/CdS sandwich NTA photoanode is 3.2% at 0.72 eV vs. RHE, 23 times as high as that of ZnO/Au and 80-folds that of the pure ZnO NTA photoanodes, respectively. The PEC and photoluminescence measurements experimentally demonstrate that the Aunanoparticles not only serve as plasmonic sensitizer to efficiently transfer the electrons from the defect level of ZnO to its conduction band via resonance coupling action of the plasmon and defect energy emission, but also serve as electron relay to transfer the electrons from the conduction band of CdS to that of ZnO, enabling the ZnO/Au/CdS sandwich NTAs to achieve greatly enhanced PEC water splitting activity. This work offers a new strategy for integrating both plasmonic sensitizer and electron relay into a photoanode for efficient conversion of solar energy to chemical energy.

Here, we first use a facile electrochemical deposition method to load Cu2O nanoparticles onto the BaTiO3 (BTO) surface to prepare BTO/Cu2O heterostructure photoanodes. Compared to the pure BTO photoanode, all BTO/Cu2O heterostructure photoanodes show outstanding visible light harvesting ability and greatly improved photoelectrochemical water splitting performance. By optimizing the loading amount of Cu2O nanoparticles, the photocurrent density achieved by BTO/Cu2O-100 photoanode is 0.26 mA/cm2 at 0 V versus Ag/AgCl, which is 2.6 times that of the bare BTO photoanode. In contrast with the photocurrent densities of the other reported BTO-based heterostructure photoanodes, the photocurrent density achieved by the present BTO/Cu2O-100 photoanode without bias voltage is much higher. Additionally, the maximum solar-to-hydrogen conversion efficiency of the BTO/Cu2O-100 heterostructure photoanode is 0.11% at 0.72 V versus reversible hydrogen electrode, approximately double that of BTO photoanode. The measurements of diffuse reflectance spectra, photoelectrochemical impedance and the room temperature photoluminescence spectra demonstrate that the improved photoelectrochemical performance contributes from the visible light absorption ability of Cu2O nanoparticles, efficient transport and separation of photogenerated electron-hole pairs, which are induced by the spontaneous polarization electric field of ferroelectric BTO, p-n junction and type-II band alignment of BTO/Cu2O heterostructure photoanode. A possible mechanism for the improved photoelectrochemical water splitting performance and charge transfer process is proposed.

ZnO/Cu2S nanotube arrays are fabricated firstly by a facile and capping-agent-free method, and the photo-electrochemical performance has been studied systematically. The results show that ZnO/Cu2S nanotube arrays achieve enhanced photo-electrochemical water splitting performance and the photocurrent densities of ZnO/Cu2S are 7.9 times than that of ZnO at 0 V versus Ag/AgCl. The performance of the ZnO/Cu2S nanotube arrays can be adjusted by changing the amount of Cu2S microcrystals. The results confirm that the enhanced photo-electrochemical performance of ZnO/Cu2S is due to the significantly improved visible light absorption, effective separation of photo-induced carriers due to the well band energy match and the formed p-n junction between ZnO and Cu2S.

In this study, three-dimensional (3D) hierarchical PbS/ZnO heterojunction microspheres were successfully fabricated by combining a facile hydrothermal method and an improved successive ionic-layer adsorption and reaction (SILAR). As an adsorbent for the first time, the adsorption activities for the methyl orange (MO) of the prepared 3D hierarchical PbS/ZnO heterojunction microspheres were investigated. By optimizing the loading of PbS nanoparticles (NPs), the 3D hierarchical PbS/ZnO heterojunction microspheres show enhanced adsorption ability for MO with a high removal rate of more than 91% and a maximum adsorption capacity of 159 mg g−1 at equilibrium time within less than 40 min. The kinetics, thermodynamics, and isotherm investigations for the adsorption process of MO over the 3D hierarchical PbS/ZnO heterojunction microspheres experimentally demonstrate that the adsorption process follows a pseudo-second-order model with the nature of spontaneous and endothermic and is well fitted with the normal Langmuir isotherm model. Based on the comparative investigations and the experimental results of kinetics, thermodynamics, and isotherm studies, a reasonable adsorption mechanism of MO over the 3D hierarchical PbS/ZnO heterojunction microspheres was proposed. This work not only describes a new semiconductor heterojunction adsorbent but also offers a new idea for the fabrication of other semiconductor heterojunction adsorbents.

ZnO nanotube arrays were synthesized by the electrodeposition method and Cu2O microcrystals with two kinds of morphologies were deposited on ZnO nanotube arrays successfully. At the deposition potential of −0.5 or −0.7 V, the cubic or spherical Cu2O microcrystals were selectively deposited on ZnO nanotube arrays. By adjusting the deposition time, Cu2O microcrystals with different sizes were obtained. The optical properties and photo-electrochemical performance of ZnO/Cu2O were measured. The results showed that the as-prepared ZnO/Cu2O heterojunction exhibited improved visible light absorption and enhanced photocurrent due to the excellent ability of Cu2O microcrystals for harvesting visible light, and the effective separation and transfer of photo-generated electrons and holes owing to p-n junction between ZnO and Cu2O. The experimental results demonstrate that the photo-electrochemical performance of ZnO/Cu2O heterojunction nanotube arrays can be manipulated by controlling the morphology and the size of Cu2O microcrystals.

This study provides insights into the charge transfer and solar light photocatalytic activity induced by the synergistic effect between defect state and plasmon in Au nanoparticle-decorated hierarchical 3D porous ZnO microspheres. Photoluminescence emission shows that the photogenerated electrons of ZnO are efficiently transferred from its defect level to the conduction band (CB) induced through the coupling action of the defect state and plasmon. Compared with the pure ZnO microsphere photocatalysts, the fabricated Au/ZnO microsphere photocatalysts show remarkably enhanced activity for the decomposition of methylene blue dyes under solar-light illumination. Moreover, the photocatalytic performance of the Au/ZnO microspheres was manipulated by tuning the size of the Au nanoparticles (NPs). When decorated with 10 nm Au NPs, the Au/ZnO microsphere photocatalyst achieves a rate constant of 0.09846 min−1, 26 and 8.5 times higher than those of the pure ZnO microsphere photocatalysts (0.00378 min−1) and the Au/ZnO microsphere photocatalysts decorated with 30 nm Au NPs (0.01154 min−1), respectively.. The enhanced photocatalytic performance of the Au/ZnO microsphere photocatalysts is ascribed to the defect state-plasmon coupling-induced efficient transfer of photogenerated electrons from the defect level to the CB of ZnO. This work enhances the understanding of the defect state-plasmon coupling-induced enhanced photocatalytic activity in metal/semiconductor heterostructure photocatalysts.

The ZnO nanotube arrays were obtained by a simple three-step method, and then Au nanoparticles and Cu2O nanocrystals were decorated onto ZnO nanotube arrays successively. The composition, morphology, optical properties and photoelectrochemical performance of the as-prepared ZnO@Au@Cu2O nanotube arrays were characterized by X-ray diffraction, scanning electron microscopy, UV–vis diffuse reflectance spectra, X-ray photoelectron spectroscopy, and photocurrent densities. The results confirmed that ZnO@Au@Cu2O nanotube arrays showed enhanced response to visible light and achieved an excellent photocurrent under visible light due to the localized surface plasmon resonance effect, visible light harvesting of Cu2O nanocrystals, effective transfer and separation of photo-generated charge carriers induced by p-n junction and well band energy match of the ZnO@Au@Cu2O nanotube arrays.

The application of single-phase ZnO in hydrogen production through photoelectrochemical (PEC) water reduction is limited because of its unability to utilize photon energy of visible light and high carrier recombination rate. Herein, a three-dimensional (3D) plasmonic photoanode consisting of Au nanoparticles/ZnFe2O4 nanosheets coated onto ZnO nanotube arrays (Au/ZnFe2O4/ZnO NTAs) is rationally designed for hydrogen generation via PEC water splitting. The measurements preformed under simulated solar light and visible light irradiation show that the hot-electron injection of Au nanoparticles (NPs) significantly enhances PEC water splitting for hydrogen generation of 3D plasmonic Au/ZnFe2O4/ZnO NTAs photoanode. Benefiting from the outstanding visible light harvesting ability of ZnFe2O4 nanosheets, efficient suppression of carrier recombination by a favorable band alignment, hot-electron injection of Au NPs and large surface area of 3D architecture, the 3D plasmonic Au/ZnFe2O4/ZnO NTAs photoanode exhibits enhanced PEC water splitting for hydrogen generation. The hydrogen generation rate obtained by 3D plasmonic Au/ZnFe2O4/ZnO NTAs photoanode is 1.5 and 5.7-fold of ZnO/ZnFe2O and ZnO NTAs photoanodes, respectively, at 0.6 V versus reference electrode (Ag/AgCl) under simulated solar light irradiation.

In this study, we show that the poor visible light photoelectrochemical (PEC) and photocatalytic activities of both wide-bandgap TiO2 and small-bandgap Bi2WO6 photocatalysts can be remarkably enhanced by constructing hierarchical Bi2WO6 nanosheet-wrapped TiO2 nanorod arrays (NRAs). X-ray photoelectron spectroscopy (XPS) measurements give direct experimental evidence for the establishment of a type II band alignment, which realizes visible light PEC performance of heterogeneous architecture through the transfer of photoexcited electrons from Bi2WO6 to TiO2. Moreover, Au nanoparticles (NPs) grown on the hierarchical Bi2WO6 nanosheets of TiO2/Bi2WO6 NRAs drastically enhance visible light PEC and photocatalytic activity of heterogeneous architectures because of surface plasmon resonance (SPR) effect. Benefiting from the synergistic effect of the type II band alignment and SPR effect, the hierarchical TiO2/Bi2WO6/Au NRAs achieve a photocurrent density of 29 μA cm−2, 11 times higher than that of TiO2 NRAs and 2.6 times as high as that of hierarchical TiO2/Bi2WO6 NRAs at 1 V vs Ag/AgCl. The hierarchical TiO2/Bi2WO6/Au NRAs exhibit remarkable stability in 2 h of light illumination. Additionally, the hierarchical TiO2/Bi2WO6/Au architectures show a significantly enhanced photocatalytic degradation for methyl blue (MB) molecules with a photodegradation of 91.5%. The study sheds new light on constructing visible light photocatalyst by forming the type II band alignment and integrating SPR effect.

We apply a facile photoreduction deposition strategy to grow Au nanoparticles (NPs) on the surfaces of TiO2 nanowire arrays (TiO2/Au NWAs) as a Raman sensitive substrate. The fabricated TiO2/Au NWAs can be used as a highly sensitive and recyclable SERS sensor for detecting the rhodamine 6 G (R6 G) molecules with a concentration as low as 10−9 M. Moreover, when irradiated with UV light, the SERS sensor with high sensitivity can be fully reproduced due to the superior self-cleaning capability of the substrate. By a comparative study on the SERS activities of R6 G molecules over the substrates of pure TiO2 NWAs, pure Au NPs and TiO2/Au NWAs, as well as the photoresponse performance of pure TiO2 and TiO2/Au NWAs under visible light illumination, we provide an illuminating insight into enhanced mechanism of SERS activity for TiO2/Au NWAs. The photoresponse performances and SERS activities provide experimental evidence that enhanced SERS activity of TiO2/Au NWAs is ascribed to the efficient charge transfer among Au, TiO2 and R6 G. This work throws a new light on enhanced mechanism for SERS activity of semiconductor/noble-metal substrates, which are expected to find potential applications to fabricate highly sensitive SERS sensors for the detection of analytes.

In this study, we have developed a facile chemical bath deposition (CBD) method to grow p-type Cu2O nanoparticles on n-type TiO2 nanowire arrays (TiO2 NWAs) to fabricate TiO2/Cu2O core/shell heterojunction nanowire arrays (TiO2/Cu2O core/shell NWAs). When used as photoelectrode, the fabricated TiO2/Cu2O core/shell NWAs show improved photoelectrochemical (PEC) water splitting activity to pure TiO2 NWAs. The effects of the CBD cycle times on the PEC activities have been studied. The TiO2/Cu2O core/shell heterojunction nanowire array photoelectrode prepared by cycling 5 times in the CBD process achieves the highest photocurrent of 2.5 mA cm−2, which is 2.5 times higher than that of pure TiO2 NWAs. In addition, the H2 generation rate of this photoelectrode reaches to 32 μmol h−1 cm−2, 1.7 times higher than that of pure TiO2 NWAs. Furthermore, the TiO2/Cu2O core/shell heterojunction nanowire array photoelectrode shows excellent photostability and achieves a stable photocurrent of over 2.3 mA cm−2 during long light illumination time of 5 h. The enhanced photocatalytic activity of TiO2/Cu2O core/shell heterojunction nanowire array photoelectrode is attributed to the synergistic actions of TiO2 and Cu2O for improving visible light harvesting, and efficient transfer and separation of photogenerated electrons and holes.

In this paper, we designed a series of well-aligned ZnO nanorod arrays decorated with loading-controllable Au nanoparticles and studied their surface plasmon-driven photoelectrochemical (PEC) water splitting performances. The PEC water splitting ability of Au-ZnO nanorod arrays was evaluated under illumination with λ > 420 nm light. These nanorod arrays show remarkable PEC water splitting performances and achieve the highest photocurrent density of 30 μA cm−2 at 0.8 V versus Ag/AgCl. Furthermore, the PEC performance for heterogenous nanorod arrays can be effectively adjusted by controlling loading amounts of Au nanoparticles. We experimentally demonstrate that the Au-ZnO nanorod arrays show enhanced visible light absorption ability. The superior PEC performance of Au-ZnO nanorod arrays is attributed to the synergistic effects of plasmonic Au nanoparticles, ZnO semiconductor and Schottky barrier built in heterogenous nanorod array. This work provides a facile strategy to manipulate the PEC water splitting activity of Au-ZnO hybrid nanostructures by simply controlling the loading amounts of metallic Au nanoparticles. Furthermore, our research offers a potentially efficient strategy for the design and fabrication of new types of plasmonic-metal/semiconductor hybrid nanostructures with a plasmonic-enhanced PEC water splitting activity under the visible light, which are as valuable photocatalysts for solar-to-chemical/electrical energy conversion.

A highly sensitive, recyclable and self-cleaning surface-enhanced Raman scattering (SERS) substrate for rapid in situ monitoring photocatalytic degradation of dyes has been fabricated by growing Ag nanoparticles (NPs) on three-dimensional (3D) nanosheet-built ZnO microspheres (MSs). Used as a SERS substrate for the detection of Rhodamine 6 G (R6 G) molecules, the fabricated 3D Ag/ZnO MSs display high sensitivity and reproducibility as well as outstanding self-cleaning ability. The 3D Ag/ZnO MSs can detect the SERS signals of R6 G molecules even at very low concentration of 10-9 M. In the light of these outstanding performances, the 3D Ag/ZnO MSs were employed as a SERS-active substrate for rapid in situ monitoring photocatalytic degradation of R6 G molecules. The experimental results distinctively demonstrate that the enhanced photocatalytic degradation of R6 G molecules is attributed to the efficient plasmon-induced charge transfer at the interface of the Ag NPs, ZnO MSs and R6 G molecules. The as-prepared 3D Ag/ZnO MSs display potential applications for as a multifunctional platform to rapid in situ monitoring photocatalytic degradation of organic pollutants in polluted water.

In this study, a novel photoanode of ternary CdS/ZnFe2O4/Cu2O core/shell heterojunction nanorod arrays (NRAs) was fabricated via combining two-step hydrothermal method with a facile chemical bath deposition process. Under bias-free visible light irritation, the photocurrent density of the CdS/ZnFe2O4/Cu2O core/shell nanorod array (NRA) photoanode is 3.3 mA cm−2, 2.2 and 3.3-fold as high as that of CdS/ZnFe2O4 and CdS NRAs, respectively. In addition, an average H2 generation rate of the CdS/ZnFe2O4/Cu2O core/shell NRA photoanode is as high as 134 μmol h-1, 2.2-fold of CdS/ZnFe2O4 and 4.5-fold of CdS NRA photoanodes. Furthermore, the CdS/ZnFe2O4/Cu2O core/shell NRA photoanode shows a good photostability and achieves a photocurrent density of over 3 mA cm−2 during continuous light irradiation of 2 h. Significant enhancement for H2 evaluation of the CdS/ZnFe2O4/Cu2O core/shell NRA photoanode is ascribed to the efficient charge transfer and separation, which is achieved by its novel band alignment of stair-like type-II structure.

In this study, a novel three-dimensional (3D) CdS@Ni(OH)2 nanorod array (NRA) photoanode with a type-II band alignment and a p-n junction has been designed and constructed via a simple electrochemical deposition of hierarchical β-Ni(OH)2 nanosheets onto the surfaces of the CdS NRAs. The 3D CdS@Ni(OH)2 NRA photoanode fabricated under the optimal deposition current exhibits remarkably improved photoelectrochemical water splitting performance, and obtains a photocurrent density of up to 1.1 mA/cm2, 5-fold that of the pure CdS NRA photoanode. Most importantly, the solar-to-hydrogen conversion efficiency of the 3D CdS@Ni(OH)2 NRA photoanode is 3.3-fold higher than that of the pure CdS NRA photoanode at 0.67 V vs. RHE. The electrochemical and photoluminescence emission measurements confirm that the enhanced PEC water splitting capability of the prepared 3D CdS@Ni(OH)2 NRA photoanode is attributed to the efficient charge separation, which is achieved by the synergistic action of the type-II energy alignment and the p-n junction.

For potential use as a topological insulator, thin square-like Bi2Te3 nanosheets, prepared via a facile solution-based method, were subjected to detailed micro-Raman spectral measurements. The results demonstrate remarkable activation of the infrared active A1u mode in the Raman spectra despite the forbidden nature of the odd-parity A1u mode for bulk Bi2Te3 crystals. Therefore, the results unambiguously prove the crystal symmetry breaking of the thin square-like Bi2Te3 nanosheets. This study illustrates the potential applicability of micro-Raman spectroscopy as a powerful nanometrology tool for investigating the optical properties of topological insulators.

A new series of metal (II) organophosphates with the formula M(II) 2(H 2 O) 2 [O 3 PCH 2 (C 6 H 4 )CH 2 PO 3 ] ( M =Mn, Fe and Ni) have been prepared by hydrothermal synthesis. The structure consisted of two-dimensional metal–oxygen inorganic layers is pillared by p-xylylenediphosphonate to form a three dimensional framework. The layers are constructed by corner-sharing metal oxygen polyhedron. A study on the magnetism of the materials indicates the presence of spin canted antiferromagnetc interactions. The manganese and iron compounds represent the interesting 3D metal organophosphate molecular metamagnet due to spin canted antiferromagnetic with high critical temperature (40 K for Mn; 16 K for Fe). The infinite M–O–M layers are believed to be responsible for this high performance.

Abstarct Hexagonal bismuth telluride (Bi 2 Te 3 ) nanoplates and nanorings were synthesized by a simple solvothermal process. The composition, morphology and size of the as-prepared products were investigated by X-ray diffraction and transmission electron microscopy in detail. The systemically experiments have been performed to investigate the effect of alkaline additive NaOH on composition and morphology of Bi 2 Te 3 nanostructures. The results indicate that alkaline additive NaOH is not necessary for the formation of Bi 2 Te 3 nanostructures in a solvothermal process. However, NaOH plays an important role in determining the morphology and size of Bi 2 Te 3 nanostructures. When the experiment was carried out with NaOH concentration ranging from 5 to 7 M, hexagonal Bi 2 Te 3 nanoplates with edge length of 140–280 nm were synthesized. When the experiment was carried out at higher NaOH concentration of 9–11 M, hexagonal Bi 2 Te 3 nanorings were fabricated by dissolving the inner part of the hexagonal nanoplates with NaOH for the first time. A possible formation mechanism has been proposed based on the experimental results and analysis. This work may open a new rational route for the synthesis of hexagonal Bi 2 Te 3 nanorings which may have some scientific and technological applications in various functional devices.

CoFe 2 O 4 nanowire arrays were fabricated by electrodeposition of Fe 2+ and Co 2+ into anodic aluminum oxide (AAO) templates and further oxidization. The phase structure of the nanowires is cubic spinel-type, and the XRD result exhibits perfect preferred crystallite orientation along the nanowire axes. Compared with CoFe 2 O 4 nanowire arrays synthesized by other methods, the magnetic hysteresis loops demonstrate that the arrays of nanowires exhibit uniaxial magnetic anisotropy with easy magnetization direction along the nanowire axes owing to the large shape anisotropy. This approach provides a facile technology to fabricate oxide nanowires with uniaxial magnetic anisotropy.

Arrays of nanocables were electrodeposited into anodic aluminum oxide template at 40 °C in the solution of dimethylsulfoxide (DMSO) with 17 g/l FeCl 3 . The transmission electron microscope result clearly shows that the nanocables consist of light Fe–DMSO sheaths and dark Fe nanowire cores. The Fe nanowire cores are bcc structure with a preferred orientation of (1 1 0) and the sheaths of Fe–DMSO are coordination compounds of Fe with DMSO. The chemical bonds of Fe–DMSO are instable at high-temperature solution, so the content of Fe–DMSO decreases and that of Fe increases with the enhancing of electrodeposited temperature. All arrays of nanocables at different electrodeposited temperatures show an obvious anisotropy with the easy magnetizing axial parallel to the length of nanocable. With the applied field along the nanocable, the anisotropy, coercivity and squareness increase with the raise of electrodeposited temperature.

Arrays of Fe 61 Co 27 P 12 nanowire with an aspect ratio about 70 were prepared in anodic aluminum oxide templates by electrodeposition. The influences of annealing temperature on structure and magnetic properties of Fe 61 Co 27 P 12 nanowires were studied. When the specimens were annealed below 400 °C, there are no obvious changes in structure except relaxation. With the annealing temperature increasing from 400 to 600 °C, the Fe–Co phase is detected by X-ray diffraction and Mossbauer spectra. The crystalline fraction and hyperfine field can be derived from Mossbauer spectra. The room temperature magnetic hysteresis loops show that the coercivity and squareness of the nanowire arrays in parallel to the wire axis increase with the increasing of annealing temperature, which mainly attributes to the strengthening of anisotropy.

Amorphous Co–Zn alloy nanowire arrays with diameter of about 40 nm were fabricated in anodic aluminium oxide films by the electrodeposition method. Transmission electron microscope result shows that the nanowires are regular and uniform. Selected area electron diffraction and X-ray diffraction results indicate that the structure of nanowires is amorphous. Vibrating sample magnetometer is employed to study the magnetic properties of nanowire arrays at room temperature. The results show that the arrays of nanowires exhibit uniaxial magnetic anisotropy with the easy magnetization direction along the nanowire axes owing to the large shape anisotropy. When the applied magnetic field is parallel to the wire axis, the coercivity and squareness of the nanowire arrays decrease with increasing Zn concentration.

Arrays of Nd 5 Fe 95 − x B x (17 ≤ x ≤ 28) nanowires were fabricated by electrodepositing in pores of anodic aluminum oxide (AAO) templates. Transmission electron microscope result shows that the nanowires are about 40 nm in diameter and the aspect ratio is approximately 75. Selected area electron diffraction and X-ray diffraction results indicate that the nanowires are amorphous in structure at concentration x = 25. Vibrating sample magnetometer was employed to study the magnetic properties of nanowire arrays at room temperature. Due to the shape anisotropy effect, the arrays of nanowires exhibit obviously uniaxial magnetic anisotropy and the easy magnetizing axis is parallel to the nanowires. The coercivity with the magnetic field along the nanowire arrays decreases with the increasing of the B content.

Self-organized and ordered CoFe 2 O 4 nanotube arrays were prepared in porous anodic aluminum oxide template using an improved sol–gel approach. The attraction between the negatively charged sol particles and the positively charged pore wall of AAO is the causation of tube formation process. The morphology was studied by transmission electron and high-resolution field emission scanning electron microscope. A polycrystalline phase of the nanotube was found by X-ray and select area electron diffraction. Magnetic measurements showed that the magnetic orientation was weak in the arrays of nanotube, and the reason has been discussed.