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Vertical-aligned CuO nanowires have been directly fabricated on Cu foil through a facile thermal oxidation process by a hotplate at 550 °C for 6 h under ambient conditions. The intermediate layer of resorcinol-formaldehyde (RF) and silver (Ag) nanoparticles can be sequentially deposited on Cu nanowires to form CuO@RF@Ag core-shell nanowires by a two-step wet chemical approach. The appropriate resorcinol weight and silver nitrate concentration can be favorable to grow the CuO@RF@Ag nanowires with higher surface-enhanced Raman scattering (SERS) enhancement for detecting rhodamine 6G (R6G) molecules. Compared with CuO@Ag nanowires grown by ion sputtering, CuO@RF@Ag nanowires exhibited a higher SERS enhancement factor of 5.33 × 10 8 and a lower detection limit (10 -12 M) for detecting R6G molecules. This result is ascribed to the CuO@RF@Ag nanowires with higher-density hot spots and surface-active sites for enhanced high SERS enhancement, good reproducibility, and uniformity. Furthermore, the CuO@RF@Ag nanowires can also reveal a high-sensitivity SERS-active substrate for detecting amoxicillin (10 -10 M) and 5-fluorouracil (10 -7 M). CuO@RF@Ag nanowires exhibit a simple fabrication process, high SERS sensitivity, high reproducibility, high uniformity, and low detection limit, which are helpful for the practical application of SERS in different fields.

A multi-step procedure was effectively employed to synthesize innovative three-dimensional (3D) heterostructures encompassing sodium titanate (Na2Ti3O7) nanowire cores, an intermediate resorcinol–formaldehyde (RF) layer, and outer silver (Ag) nanoparticle sheaths, referred to as Na2Ti3O7@RF@Ag heterostructures. Initially, a one-step hydrothermal technique facilitated the direct growth of single-crystal Na2Ti3O7 nanowires onto a flexible Ti foil. Subsequently, a two-step wet chemical process facilitated the sequential deposition of an RF layer and Ag nanoparticles onto the Na2Ti3O7 nanowires at a low reaction temperature. Optimal concentrations of silver nitrate and L-ascorbic acid can lead to the cultivation of Na2Ti3O7@RF@Ag heterostructures exhibiting heightened surface-enhanced Raman scattering (SERS), which is particularly beneficial for the detection of rhodamine B (RhB) molecules. This phenomenon can be ascribed to the distinctive geometry of the Na2Ti3O7@RF@Ag heterostructures, which offer an increased number of hot spots and surface-active sites, thereby showcasing notable SERS enhancement, commendable reproducibility, and enduring stability over the long term. Furthermore, the Na2Ti3O7@RF@Ag heterostructures demonstrate remarkable follow-up as first-order chemical kinetic and recyclable photocatalysts for the photodecomposition of an RhB solution under UV light irradiation. This result can be attributed to the enhanced inhibition of electron–hole pair recombination and increased surface-active sites. [ABSTRACT FROM AUTHOR]

In this study, the effect of stacking faults (SFs) on electromigration in silver nanowires (AgNWs) in particular, with respect to their effects on necking and void growth, is investigated. The galvanic replacement reaction is used to synthesize the AgNWs in bulk at low cost. By varying the concentration of silver nitrate, AgNWs are obtained with and without SFs. In situ TEM analysis provides strong evidence that the SFs can effectively suppress the migration of surface atoms. Furthermore, an investigation of the void growth process reveals that SF facets parallel to the {111} plane contribute to the anisotropic change in morphology and slow down the rate of void growth by 135 times. Thus, planar defects can be beneficial to extending the lifetimes of devices by causing intrinsic changes to the material properties. [ABSTRACT FROM AUTHOR]

• CuO/ZnO heterostructured nanomaces have directly grown on the copper gauze. • CuO/ZnO heterostructures exhibit high photocatalytic efficiency and reusability. • CuO/Ag/ZnO/Ag heterostructured nanomaces exhibited higher photocatalytic activity. • Ag nanoparticles play a critical role to enhance the photocatalytic efficiency. • This study provides a new strategy to construct the quaternary heterostructured arrays. The CuO/ZnO heterostructured nanomaces can be directly grown on the copper gauze substrates with CuO nanowires by a wet chemical approach at the lower reaction temperature. The concentration of ZnO precursor can easily control the sizes of ZnO branched nanowires. CuO/ZnO heterostructured nanomaces presented superior photocatalytic activity toward rhodamine 6 G removal compared with commercial ZnO or TiO 2 nanoparticles under low-powered UV-light irradiation. Further investigation has revealed that CuO/ZnO heterostructured nanomaces significantly improved activity as a recyclable photocatalyst for the degradation of rhodamine 6 G. Also, the uniform sizes of Ag nanoparticles can decorate onto the interface and surface of CuO/ZnO heterostructured nanomaces via a sample ion-beam sputtering method. The quaternary CuO/Ag/ZnO/Ag heterostructured nanomaces can provide the adequate separation of photoinduced electron-hole pairs and more surface active sites, which exhibited a higher photocatalytic efficiency rather than CuO/ZnO heterostructured nanomaces. [ABSTRACT FROM AUTHOR]

Single-crystalline Cu-doped ZnO nanowires have been directly grown on the flexible brass mesh substrates in a large-scale by using a one-step annealing process under ambient condition. Cu-doped ZnO nanowires on the dense brass mesh substrates can provide a higher surface-to-volume ratio and better stability against aggregation, which exhibit excellent photocatalytic activity rather than the different amounts of commercial TiO 2 nanopowders under a 10 W UV light irradiation. In addition, Cu-doped ZnO nanowires are also revealed a good dynamic photocatalytic efficiency, which shall be beneficial in industrial wastewater treatment. [ABSTRACT FROM AUTHOR]

Aligned ZnO nanowire arrays have been grown on the silicon substrates with ZnO seed layer by an aqueous chemical growth process at low reaction temperature. The volumes of ammonium hydroxide solution are not only controlled by the dimension and density of ZnO nanowires, but are also influenced by their optical emission property. The ZnO nanowire arrays exhibit very strong and broad green emission from defect in the cathodoluminescence spectrum. In addition, the ZnO nanowires grown on the silicon substrates can serve as effective and convenient recyclable photocatalysts. Only a very slight decrease in the photodecomposition rate was observed after ten cycles of the photocatalysis experiment. [ABSTRACT FROM AUTHOR]

Abstract: This study examines the usage of well-patterned Au nanoparticles (NPs) as a catalyst for one-dimensional growth of single crystalline Si nanowires (NWs) through the vapor-liquid-solid (VLS) mechanism. The study reports the fabrication of monolayer Au NPs through the self-assembly of Au NPs on a 3-aminopropyltrimethoxysilane (APTMS)-modified silicon substrate. Results indicate that the spin coating time of Au NPs plays a crucial role in determining the density of Au NPs on the surface of the silicon substrate and the later catalysis growth of Si NWs. The experiments in this study employed optical lithography to pattern Au NPs, treating them as a catalyst for Si NW growth. The patterned Si NW structures easily produced and controlled Si NW density. This approach may be useful for further studies on single crystalline Si NW-based nanodevices and their properties. [Copyright &y& Elsevier]

In this study, we fabricated Er-doped ZnO/CuS/Au core-shell nanowires using two-step wet chemical methods and an ion-sputtering method on a glass substrate as a bifunctional photocatalytic and surface-enhanced Raman scattering (SERS) substrate. The characteristic properties of as-prepared photocatalysts were confirmed by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, DR/UV-Vis spectroscopy, and photoluminescence spectroscopy. Compared with Er-doped ZnO nanowires and Er-doped ZnO/CuS core-shell nanowires, Er-doped ZnO/CuS/Au core-shell nanowires exhibited remarkably photocatalytic activity to degrade acid orange 7 solutions under blue LED light. These results ascribed to the Er-doped ZnO/CuS/Au core-shell nanowires can enhance the visible-light absorbance and the separation efficiency of photogenerated electron-hole pairs, inducing their higher photocatalytic activity under blue LED light. In addition, Er-doped ZnO/CuS/Au core-shell nanowires exhibit high sensitivity, a low detection limit (10−6 M), uniformity, recyclability, and stability of SERS performance for detected acid orange 7. [ABSTRACT FROM AUTHOR]

• H 2 Ti 3 O 7 nanowires have directly synthesized on the Ti foil by simple hydrothermal and ion‐exchange processes. • H 2 Ti 3 O 7 nanowires revealed very prominent blue emission from surface oxygen vacancies. • H 2 Ti 3 O 7 nanowires exhibited high efficient and reusable photocatalysts under visible-light irradiation. • Holes and hydroxyl radicals played central roles in rhodamine 6G photodegradation. • H 2 Ti 3 O 7 @Ag heterostructures can provide an excellent SERS-active substrate. In the present work, we reported one kind of photocatalytic and surface-enhanced Raman scattering substrate, H 2 Ti 3 O 7 nanowires, which prepared on the Ti foil by the hydrothermal and ion‐exchange methods. The morphologies, crystal structures, chemical compositions, optical properties of the as-prepared substrates investigated via the different kinds of characterization techniques. H 2 Ti 3 O 7 nanowires revealed remarkably enhanced visible-light photocatalytic activity for the degradation of rhodamine 6 G solution compared to Na 2 Ti 3 O 7 nanowires, TiO 2 nanowires, and commercial photocatalysts (TiO 2 and ZnO nanoparticles). These results attributed to the H 2 Ti 3 O 7 nanowires with a higher concentration of oxygen vacancies can enhance the visible-light absorbance, resulting in the higher photocatalytic activity under the visible-light irradiation. The radical-trapping test shows that holes and hydroxyl radicals played central roles in rhodamine 6 G photodegradation. The deposition of Ag nanoparticles on the H 2 Ti 3 O 7 nanowires can also use as a highly sensitive surface-enhanced Raman scattering substrate for detecting rhodamine 6 G solution with a concentration as low as 10−9 M by the ion-sputtering system. [ABSTRACT FROM AUTHOR]

ZnO nanostructures were grown on the stainless steel mesh substrates using an aqueous chemical growth method. The different additives (such as 1,3-diaminopropane and polyethyleneimine) can be used to control the morphology of ZnO nanostructures. ZnO nanowires exhibit very prominent green emission and week UV emission from defect and band gap in the cathodoluminescence spectrum, respectively. The different morphology of ZnO nanostructures on the stainless steel mesh substrates can be used to irradiate UV light for the photocatalytic degradation of four kinds of organic pollutants, such as methylene blue, rhodamine 6G, methyl orange, and 4-nitrophenol. The ZnO nanowires can provide a higher surface-to-volume ratio and stronger defect emission, resulting in their highest photocatalytic performance in 10 W UV light irradiation. The ZnO nanowire arrays on the stainless steel mesh substrates provide a large-scale, facile, low-cost, high surface area, and high photocatalytic efficiency, which shall be of significant value for practical applications of the decomposition of environment pollutants and reusing of wastewater treatment. [ABSTRACT FROM AUTHOR]