Morphology Of Nanowires Research Articles

Chemical vapor etching of silicon wafer for the synthesis of highly dense and aligned sub-5 nm silicon nanowire arrays

We investigated the key chemical vapor etching parameters governing the morphology of Si nanowires. Highly aligned sub-5 nm Si nanowires can be achieved by controlling the oxidant gas concentration, reaction temperature, and hydrogen concentration.

Characterization and ohmic contact of hydrothermally synthesized vertical ZnO and Ag/ZnO nanowires

Vertically aligned ZnO nanowire arrays were synthesized by two-step hydrothermal method. ZnO seed layers were prepared on substrate by using anhydrous ethanol and zinc acetate dihydrate solution, followed by the generation of ZnO nanowire arrays by low-temperature liquid-phase hydrothermal methods. The ZnO nanowire arrays were prepared under different conditions to compare the effects of growth conditions on the morphology of ZnO nanowires, in order to explore the optimal growth conditions for ZnO nanowire arrays used in semiconductor device. The morphological changes of ZnO nanowire arrays grown under different conditions were systematically analyzed by SEM, XRD and other characterization means. The results show that the seed solution concentration, growth solution concentration, doping concentration and growth time all have certain effects on the morphology of ZnO nanowire arrays. Besides, the Ag/ZnO ohmic contact were investigated, the optimal annealing temperatures of 450 °C was obtained.

Enhanced Electron Correlation and Significantly Suppressed Thermal Conductivity in Dirac Nodal-Line Metal Nanowires by Chemical Doping.

Enhancing electron correlation in a weakly interacting topological system has great potential to promote correlated topological states of matter with extraordinary quantum properties. Here, the enhancement of electron correlation in a prototypical topological metal, namely iridium dioxide (IrO2 ), via doping with 3d transition metal vanadium is demonstrated. Single-crystalline vanadium-doped IrO2 nanowires are synthesized through chemical vapor deposition where the nanowire yield and morphology are improved by creating rough surfaces on substrates. Vanadium doping leads to a dramatic decrease in Raman intensity without notable peak broadening, signifying the enhancement of electron correlation. The enhanced electron correlation is further evidenced by transport studies where the electrical resistivity is greatly increased and follows an unusual dependence on the temperature (T). The lattice thermal conductivity is suppressed by an order of magnitude via doping even at room temperature where phonon-impurity scattering becomes less important. Density functional theory calculations suggest that the remarkable reduction of thermal conductivity arises from the complex phonon dispersion and reduced energy gap between phonon branches, which greatly enhances phase space for phonon-phonon Umklapp scattering. This work demonstrates a unique system combining 3d and 5d transition metals in isostructural materials to enrich the system with various types of interactions.

Fabrication of platinum-cobalt nanowires by centrifugal electrospinning as oxygen reduction catalyst for PEMFC

Investigation for novel catalytic materials is quite important for the development of fuel cell as well as hydrogen economy. In this study, platinum-cobalt (PtCo) bimetallic nanowires are prepared successfully by the centrifugal electrospinning technique and their potential as electrocatalyst is evaluated for proton exchange membrane fuel cell (PEMFC). The influences of operation conditions on nanowire morphology are studied, which include the rotation rate of spinneret, applied electric field, and nanowire composition. The electrochemical performance of the prepared nanowires is studied by performing the tests of cyclic voltammetry (CV) and linear sweep voltammetry (LSV) to characterize the electrochemical active surface area (ECSA) and oxygen reduction reaction (ORR) activity. The accelerated degradation tests (ADT) are also conducted to examine the durability of the nanowires. The membrane electrode assembly (MEA) using PtCo nanowires as cathode electrocatalyst is also made and its performance is compared with conventional MEA using Pt/C catalyst. It is found that under the situation of 1600 rpm of rotation rate, 12 cm of collection distance, and 13 kV of applied voltage, PtCo nanowires can be obtained with excellent morphology and the minimum mean diameter is 76 nm for the case of atomic ratio Pt:Co = 4:1. The corresponding ECSA is 41.2 m2g−1 and the LSV and ADT results show the resultant PtCo nanowires exhibit better ORR activity and durability than Pt/C catalyst.

CuO Nanowires Fabricated by Thermal Oxidation of Cu Foils towards Electrochemical Detection of Glucose

In view of the various stability issues and high cost of enzymatic glucose biosensors, non-enzymatic biosensors have received great attention in recent research and development. Copper oxide (CuO) nanowires (NWs) were fabricated on Cu foil substrate using a simple thermal oxidation method. The phase and morphology of the CuO NWs could be controlled by synthesis temperature. Variation in oxidation states enables CuO NWs to form Cu (III) species, which is crucial in catalysing the eletro-oxidation of glucose. The Cu-based metal/oxide composite electrode works as a non-enzymatic biosensor that adapts to the fast, dynamic change in glucose concentration, with a low saturation concentration (~0.7 mM) and a lower detection limit of 0.1 mM, making CuO NWs an excellent sensor towards impaired fasting glucose. The simplicity, cost-effectiveness and non-toxicity features of this study might make a way for potentially scalable application in glucose biosensing.

Hierarchically Oriented Jellyfish‐Like Gold Nanowires Film for Elastronics

AbstractStretchable electronics (i.e., Elastronics) are essential to the realization of next‐generation wearable bioelectronics for personalized medicine, due to their unique skin‐conformal features ideal for seamless integration with the human body. Significant progress has been made to nanowire‐based elastronics with promising applications ranging from electronic‐skin to advanced energy harvest systems. However, it remains a key challenge to rationally control over the nanowire morphology and configurations to achieve desired multifunctionality. Herein, a stretchable jellyfish‐like gold nanowires film with high conductivity and stretchability is presented by using gold nanostar‐seeded nanowire growth method. They exhibit unique hierarchically oriented structure with gold nanostars as the multi‐branched active sites (top layer) and vertically intertwined nanowires (bottom layer) trailing below the nanostars. Such nanowires film can be stretched up to 200% with a retaining low normalized resistance of 13.8 due to the unique hierarchical structure. Furthermore, the film can be used as stretchable supercapacitor with a 92% capacitance retention and superior durability even after 5000 electrochemical scanning cycles. The method is general, which can be further expanded to other metallic seeds, hence, representing a low‐cost yet efficient strategy for the fabrication of stretchable elastronics and robust energy storage devices for on‐body biosensing and bioelectronics.

Ag-catalyzed GaSb nanowires for flexible near-infrared photodetectors

High-quality narrow bandgap semiconductors nanowires (NWs) challenge the flexible near-infrared (NIR) photodetectors in next-generation imaging, data communication, environmental monitoring, and bioimaging applications. In this work, complementary metal oxide semiconductor-compatible metal of Ag is deposited on glass as the growth catalyst for the surfactant-assisted chemical vapor deposition of GaSb NWs. The uniform morphology, balance stoichiometry, high-quality crystallinity, and phase purity of as-prepared NWs are checked by scanning electron microscopy, energy dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, and X-ray diffraction. The electrical properties of as-prepared NWs are studied by constructing back-gated field-effect-transistors, displaying a high I on/I off ratio of 104 and high peak hole mobility of 400 cm2/(V·s). Benefiting from the excellent electrical and mechanical flexibility properties, the as-fabricated NW flexible NIR photodetector exhibits high sensitivity and excellent photoresponse, with responsivity as high as 618 A/W and detectivity as high as 6.7 × 1010 Jones. Furthermore, there is no obvious decline in NIR photodetection behavior, even after parallel and perpendicular folding with 1200 cycles.

Highly sensitive temperature probe fabricated by high aspect ratio Eu-BTC nanowire

Metal-organic frameworks (MOFs) have shown great potential as a new platform for developing solid-state light-emitting temperature probes. Herein, we synthesized Eu-BTC (MOFs) with controllable nanowire and nanorod morphologies by changing solvents. Eu-BTC Nanowire was produced from DMF with a size of 15 µm and a 21.5 % photoluminescence quantum yield (PLQY), while the nanorods from H 2 O yielded with a size of 200 nm (PLQY=17.4 %). The Eu-BTC materials exhibited highly variable temperature properties depending on the morphology. Eu-BTC Nanowire from DMF presented better temperature dependence as a highly sensitive temperature probe owing to its higher linearity and more excellent temperature-dependent reversibility, which further demonstrated its potential for application as a temperature probe. While, the Eu-BTC nanorod from H 2 O showed a non-linear relationship with temperature and low temperature-dependent reversibility, making it unsuitable as a temperature probe. The morphologies-dependent luminescence sensing mechanism of Eu-BTCs and the heat conduction induced by surface defects mechanism were proposed. This work provides theoretical guidance for developing highly sensitive and non-contact temperature probes, especially for the morphology-dependent temperature probes. ● Eu-BTCs (MOF) with controllable morphologies were successfully synthesized. ● Eu-BTC nanowires demonstrated highly temperature dependence and reversibility. ● Provide theoretical guidance for developing highly sensitive temperature probes.

Superlattice-Induced Variations in Morphological and Emission Properties of GaInN/GaN Multiquantum Nanowire-Based Micro-LEDs.

Core-shell GaInN/GaN multiquantum shell (MQS) nanowires (NWs) are gaining great attention for high-efficiency micro-light-emitting diodes (micro-LEDs) owing to the minimized etching region on their sidewall, nonpolar or semipolar emission planes, and ultralow density of dislocations. In this study, we evaluated the changes in NW morphologies and the corresponding device properties induced by GaInN/GaN superlattice (SL) structures. The cathodoluminescence intensities of the samples with 20 and 40 pairs of SLs were about 2.2 and 3.4 times higher, respectively, than that of the sample without SLs. The high-resolution scanning transmission electron microscopy (STEM) inspection confirmed that the high growth temperature of SLs prevented growth in the semipolar plane region close to the n-GaN core. A similar phenomenon was also observed for the GaN quantum barriers of the semipolar MQS region under a high growth temperature of 810 °C. This phenomenon was ascribed to the passivation of the semipolar plane surface by hydrogen atoms and the high probability of decomposition through NH3 or N-H-related bonds. Although no clear SL grew on the semipolar plane near the n-core region, the top area of the nonpolar plane SL was expected to adequately suppress the point defects propagating from the n-GaN core to the semipolar plane MQS. The electroluminescence (EL) spectra and light output curves demonstrated a clear enhancement of more than 3-folds compared to the fabricated micro-LEDs without SL structures, which was associated with the improved crystalline quality of the MQS and enlarged area of the semipolar planes. Moreover, by increasing the growth time of GaN quantum barriers, the EL emission intensity of the micro-LED devices exhibited a 4-fold improvement owing to the reduced carrier overflow in the thickened GaN barriers on the semipolar (11̅01) planes. Thus, the results verified the possibility of realizing highly efficient NW-based micro-LEDs by optimizing the NW morphology using SL structures.

Incremental Preparation and Absorbing Properties of SiC Nanowires

With the rapid development of science and technology, the requirements for absorbing materials in various fields are more and more high. SiC material, as a kind of absorbing materials, has a variety of excellent characteristics, and it is one of the key research absorbing materials. This experiment chose activated carbon powder and silicon powder to grow the SiC nanowires on the graphite paper. In the process, activated carbon atoms on the surface of the graphite paper and coarse porous structure are more likely to contribute to formation of SiC crystal nucleus. In addition, increasing the water vapor in the experiment can improve the output of SiC nanowires, which is a highlight of preparing and improving the yield of SiC nanowires in this experiment. The microstructure and morphology of the SiC nanowires were characterized by XRD and SEM, and the microwave absorbing properties of the SiC nanowires was tested. When the molar C/S ratio is 2: 1 and the reaction sintering temperature is 1300℃, the SiC nanowires have smooth and uniform surface and high aspect ratio. At the same time, by studying the wave absorption properties, it is found that the SiC nanowires prepared have good dielectric properties and high reflection loss rate.

Crystal Design and Photoactivity of TiO2 Nanorod Template Decorated with Nanostructured Bi2S3 Visible Light Sensitizer.

In this study, TiO2-Bi2S3 composites with various morphologies were synthesized through hydrothermal vulcanization with sputtering deposited Bi2O3 sacrificial layer method on the TiO2 nanorod templates. The morphologies of decorated Bi2S3 nanostructures on the TiO2 nanorod templates are controlled by the duration of hydrothermal vulcanization treatment. The Bi2S3 crystals in lumpy filament, nanowire, and nanorod feature were decorated on the TiO2 nanorod template after 1, 3, and 5 h hydrothermal vulcanization, respectively. Comparatively, TiO2-Bi2S3 composites with Bi2S3 nanowires exhibit the best photocurrent density, the lowest interfacial resistance value and the highest photodegradation efficiency towards Rhodamine B solution. The possible Z-scheme photoinduced charge separation mechanism and suitable morphology of Bi2S3 nanowires might account for the high photoactivity of TiO2 nanorod-Bi2S3 nanowire composites.

Oxygen vacancy engineering on cerium oxide nanowires for room-temperature linalool detection in rice aging

It is a huge challenge for metal oxide semiconductor gas sensors to inspect volatile organic compounds (VOCs) at room temperature (RT). Herein, the effective utilization of cerium oxide (CeO2) nanowires for RT detection of VOCs was realized via regulating its surface chemical state. Oxygen vacancy engineering on CeO2 nanowires, synthesized via hydrothermal method, can be manipulated by annealing under various controlled atmospheres. The sample annealed under 5%H2+95%Ar condition exhibited outstanding RT sensing properties, displaying a high response of 16.7 towards 20 ppm linalool, a fast response and recovery time (16 and 121 s, respectively), and a low detection of limit of 0.54 ppm. The enhanced sensing performance could be ascribed for the synergistic effects of its nanowire morphology, the large specific surface area (83.95 m2/g), and the formation of extensive oxygen vacancy accompanied by an increase in Ce3+. Additionally, the practicability of the sensor was verified via two varieties of rice (Indica and Japonica rice) stored in various periods (1, 3, 5, 7, 15, and 30 d). The experimental results revealed that the sensor was able to distinguish Indica rice from Japonica rice. Accordingly, the as-developed sensor delivers a strategic material to develop high-performance RT electronic nose equipment for monitoring rice quality.

Influence of different carbon and SnO2 ratios on the activity of PtIr/C (SnO2)1 catalysts toward methanol oxidation

• PtIr/C 0.40 (SnO 2 ) 0.60 nanowires showed enhanced catalytic activity toward methanol oxidation. • The synergy between C and SnO 2 as support results in a high catalytic performance. • The PtIr/C 0.40 (SnO 2 ) 0.60 catalyst displayed the lowest resistance to charge transfer. • The composition PtIr/C 0.40 (SnO 2 ) 0.60 is more stable than the other catalysts. • Different affinity between PtIr NWs and carbon or tin oxide results in different agglomeration of the NWs. PtIr nanowires (NWs) with a fixed ratio of 90% Pt and 10% Ir were supported in mixtures of Vulcan XC-72 R carbon and tin oxide (SnO 2 ) in the proportions of 50:50, 40:60, 30:70, 20:80, and 10:90 of carbon and SnO 2 . We successfully synthesized PtIr NWs by chemical reduction of the metallic precursors with formic acid and tested them toward methanol electro-oxidation in acidic media. Neither surfactants nor templates were used during the syntheses. The electrochemical study was conducted by CO-stripping, cyclic voltammetry, chronoamperometry, and steady-state polarization curves. The PtIr NWs have a higher affinity to be anchored onto the carbon support than on SnO 2 , resulting in different distribution and agglomeration of the NWs that thereby has substantial consequences on the catalytic activity of the composites. The PtIr/C 0.4 (SnO 2 ) 0.6 catalytic composite exhibited the highest activity toward methanol oxidation. The high catalytic performance displayed by the PtIr/C 0.4 (SnO 2 ) 0.6 composite results from the synergy between C and SnO 2 as supports (specifically in this proportion), Ir as the co-catalyst, and the morphology of the nanowires. Therefore, these combined effects result in greater mobility of OH ads and CO ads , facilitating the CO removal from the catalyst surface and allowing better methanol adsorption for further oxidation. The PtIr/C 0.4 (SnO 2 ) 0.6 catalyst also showed the lowest resistance to charge transfer compared with the other binary catalysts. Thus, the use of SnO 2 + C as supports and PtIr nanocatalysts with NW morphology results in highly active materials toward methanol oxidation, which are promising to compose anodes for direct methanol fuel cells.

Effect of CuS buffer layer on the structural and optical properties of TeO2 nanowires: a comparative study

The current work concerns with the effects of cupper sulfide (CuS) buffer layer on morphological, structural and optical properties of tellurium dioxide (TeO2) nanostructured thin films synthesized by vapor transport method. Single crystalline tetragonal TeO2 crystallographic phase with enhanced peak intensity and crystallinity for CuS/TeO2 film are observed by x-ray diffraction analysis. Scanning electron microscopy examinations revealed small rod-like morphology for TeO2 and randomly oriented nanowires morphology for CuS/TeO2 samples. The estimated optical band gap energies were 3.78 and 3.63 eV for TeO2 and CuS/TeO2 nanostructured films, respectively. The photoluminescence of CuS/TeO2 film was enhanced and red-shifted from 450 to 455 nm by the presence of CuS layer. The effective charge carrier life times were 0.14 ns and 1.92 ns for TeO2 and CuS/TeO2 films, respectively. These results could be beneficial for optoelectronic devices such as light emitting devices.

Selective Area Growth of GaN Nanowire: Partial Pressures and Temperature as the Key Growth Parameters

Selective area growth of Ga-polar GaN nanowires by metal organic chemical vapor deposition provides a path to achieve arrays of uniform nanowires with controllable dimensions. A systematic investigation on the growth parameters of GaN nanowires demonstrates that although a low V/III ratio and low precursor flows are necessary, V/III ratio is not a sufficient parameter to determine the morphology of GaN nanowires. Partial pressures of the constituent gases, on the other hand, can be used as a single parameter, at a particular growth temperature, to explain the resulting morphology. By correlating the partial pressures of precursors and H2 in the carrier gas with the morphology of the nanowires, we can then determine the flow rates for precursors and hence the range of V/III ratios required for achieving the growth of GaN nanowires.

Synergistic effect of Co/Ni bimetallic metal–organic nanostructures for enhanced electrochemical energy storage

Introducing a secondary metal ion is an effective strategy to significantly enhance the electrochemical performance of monometallic metal–organic frameworks (MOFs). Herein, we synthesize a series of cobalt–nickel bimetallic MOFs (Co/Ni-MOFs) by the Co2+ substitution into Ni-MOF ({Ni3(OH)2(tdc)2(H2O)4}n, H2tdc = 2,5-thiophenedicarboxylic acid). The Co/Ni-MOF-2:1 with optimal Co/Ni ratio possesses improved electrical conductivity, intrinsic reactivity, and stability. Compared with the monometallic Ni-MOF, the bimetallic Co/Ni-MOF-2:1 with nanowire morphology achieves a higher specific capacitance (610 F g−1 at a current density of 0.5 A g−1), a better rate capacity (88 % capacitance retention at 5 A g−1) and cycling performance (72 % retention after 5000 cycles). Moreover, the asymmetric supercapacitor constructed with Co/Ni-MOF-2:1 and activated carbon exhibits a high specific capacitance (228 F g−1 at 0.5 A g−1) and excellent cycling stability (95.5 % of capacitance retention after 5000 circulations at 5 A g−1).

Electrodeposited cobalt sulfide nanolayer fenced nickel-copper carbonate hydroxide nanowires as an electrode for hybrid supercapacitors: A wind turbine-driven energy storage system for portable applications

Metal carbonate hydroxides/sulfides have attracted great interest from researchers in the energy storage-related fields due to their versatile electrochemical characteristics. Moreover, the synthesis of such a combination of materials is a challenging task. Herein, nickel-copper carbonate hydroxides with nanowire morphology (i.e., NiCu NWs) was in situ prepared over the carbon textile by a facile hydrothermal method. The synthesized NiCu-2 with equimolar salt concentrations (Ni-25 mM; Cu-25 mM) delivered a superior areal capacity of 65.5 µAh cm−2 at 1.5 mA cm−2 than the other two NiCu electrodes. To further improve the redox chemistry and electrochemical performance, cobalt sulfide (CS) nanolayer was electrodeposited on the NiCu NWs to make CS@NiCu-2 composite. The composite material with the combined redox features of both CS and NiCu materials as well as the hybrid morphology exhibited an improved areal capacity of 275.6 µAh cm−2 at the same current density. Furthermore, the hybrid supercapacitor (HSC) was fabricated using the CS@NiCu-2 as a positive electrode and the activated carbon as a negative electrode. For the fabricated device, a good areal capacitance of 410 mF cm−2 was achieved along with the maximum energy and power densities of 131.2 µWh cm−2 and 15000 µW cm−2, respectively. Besides, the practical applicability of HSC was tested by powering electronic gadgets.

Uncovering the machining mechanism of polycrystalline gold nanowires by nanoskiving

The unique size effects of nanowires have inspired their implementation in superconducting materials, micro/nano electromechanical systems, and flexible devices. Nanoskiving technology has demonstrated significant potential for nanowire preparation owing to the low equipment requirements, simple operation, and wide material compatibility compared with traditional lithographic nanofabrication methods. However, the increasing application of nanowires has imposed strict requirements regarding their microstructure, morphology, and size accuracy. Limited research efforts have focused on the nanowire formation mechanism during nanoskiving, and therefore, it is difficult to prepare high-quality nanowires using this technique. The present study investigates the effects of the cutting depth on the machining (nanoskiving) mechanism of polycrystalline gold nanowire preparation. Molecular dynamics simulations indicate that the interference of grain boundaries and the extrusion of the tool lead to the formation and evolution of sub-grains. The specific energy, dislocation density, and nanowire thickness deviation all increase exponentially with decreasing depth of cut, thereby revealing a significant size effect. The nanowire microstructures, morphology, and dimensions are measured experimentally using transmission electron microscopy and atomic force microscopy, and the results are consistent with the simulations. This work provides insights into the cutting deformation mechanism during the nanoskiving of polycrystalline gold materials and contributes to the precise and controllable fabrication of nanostructures by the nanoskiving method.

Enhanced coercivity in Co nanowires via manipulation of head morphology

Ferromagnetic nanowires based on the assembly of shape anisotropy seem apt candidates as rare-earth free permanent magnetic materials. Here, the relation between the head morphology of the Co nanowires and their magnetic coercivity is investigated. The Co nanowires with different head morphology such as diabolo, cylinder, and capped cylinder were synthesized via the polyol process. We demonstrate that the fine manipulation of the head morphology is effective in enhancing the coercivity of Co nanowires. The highest coercivity up to 9.4 kOe was achieved in the capped cylindrical Co nanowires. The underlying magnetic reversal mechanisms of Co nanowires with different head morphology were revealed through micromagnetic simulations. The enhanced coercivity may attribute to the quasi-coherent magnetization reversal mechanism and the relatively low and uniform distribution of local demagnetization field in the capped cylindrical Co nanowires. This work can provide instructive information for the design of high-performance ferromagnetic nanowires for permanent magnetic applications.

(Invited) Epitaxial Electrodeposition of Wide Bandgap Semiconductors for Transparent and Flexible Electronics

Single-crystal silicon is the bedrock of semiconductor devices due to the high crystalline perfection that minimizes electron-hole recombination, and the dense SiOx native oxide that minimizes surface states. One issue with the material is that it is both brittle and opaque. There is interest in moving beyond the planar structure of conventional Si-based chips to produce flexible and transparent electronic devices such as wearable solar cells, sensors, and flexible displays. In this talk we will discuss the electrodeposition of transparent, wide bandgap semiconductors such as ZnO, CuI, and CuSCN that can be produced as epitaxial films on single-crystal and single-crystal-like substrates. These epitaxial films have an orientation that is controlled by the substrate, with electronic properties that mimic those of single crystals. The talk will emphasize the electrodeposition of the wide bandgap hole conductors CuI and CuSCN. They are electrodeposited by electrochemically reducing Cu(II)EDTA to Cu(I) in the presence of either iodide or thiocyanate anions. Cubic CuI deposits as dense films on Si(111), and CuSCN deposits as nanowires on Au(111). The CuI is epitaxial on the Si(111) in spite of a 2.4 nm thick interfacial SiOx layer. The rectifying p-CuI/SiOx/n-Si heterojunction diode shows an ideality factor of 1.5, a built-in voltage of 0.67 V, and a barrier height of 0.91 eV. The crystal structure and morphology of the CuSCN nanowires can be controlled by varying the SCN-/Cu(II) ratio in solution (see Fig. 1). We also show that the epitaxial films can be removed by a simple lift-off procedure to produce single-crystal-like flexible foils of transparent semiconductors.Fig. 1 – Controlling the crystal structure and morphology of CuSCN nanowires through the SCN-/Cu(II) ratio in solution. Top micrographs are of rhombohedral CuSCN deposited using SCN-/Cu(II) = 4, and the bottom micrographs are of hexagonal CuSCN deposited using SCN-/Cu(II) = 2. The nanowires were both on Au(111), and were deposited at a potential of -0.4 V vs. Ag/AgCl. Figure 1