The surface coating of a gas reaction electrode with layered double hydroxides (LDHs) featuring various electrode catalyst activities was prepared via electrodeposition and the subsequent crystal growth of LDHs. LDH formation was confirmed by X-ray diffraction and Raman scattering measurements after subsequent crystal growth on respective electrodeposited precursor films in Ni-Fe and Zn-Al LDH systems. However, the crystal growth of LDHs in Ni-Mn and Cu-Mn systems was observed on the Mg-Al LDH-electrodeposited films. LDH films were also deposited on the surface of a carbon paper electrode with a rugged surface via electrodeposition and subsequent crystal growth. Using the prepared LDH-coated carbon paper electrodes, the electrode catalytic activity for the oxygen reduction reaction (ORR) was examined. For Ni-Mn, Ni-Al and Ni-Fe LDH-coated carbon paper electrodes, the threshold voltages of the ORR decreased. Hence, the LDHs electrodeposited on a gas reaction electrode have high electrochemical catalytic activity for the ORR.

The fibrous scaffolds for bone tissue engineering that mimic the extracellular matrix with bioactive and bactericidal properties could provide adequate conditions for regeneration of damaged bone. Electrospun ultrathin fiber covered with nano-hydroxyapatite is a favorable fibrous scaffold design. We developed a fast and reproducible strategy to produce polyvinylidene fluoride (PVDF)/nano-hydroxyapatite (nHAp) nanofibrous scaffolds with bactericidal and bioactive properties. Fibrous PVDF scaffolds were obtained first by the electrospinning method. Then, their surfaces were modified using oxygen plasma treatment followed by electrodeposition of nHAp. This process formed nanofibrous and superhydrophilic PVDF fibers (133.6 nm, fiber average diameter) covered with homogeneous nHAp (202.6 nm, average particle diameter) crystals. Energy-dispersive X-ray spectrometry demonstrated the presence of calcium phosphate, indicating a Ca/P molar ratio of approximately 1.64. X-ray diffraction, Fourier transform infrared spectroscopy, and Raman spectroscopy spectra identified β-phase of nHAp. Thermal analysis indicated a slight reduction in stability after nHAp electrodeposition. Bactericidal assays showed that nHAp exhibited 99.8% efficiency against Pseudomonas aeruginosa bacteria. The PVDF/Plasma and PVDF/nHAp groups had the highest cell viability, total protein, and alkaline phosphatase activity by 7 days after exposure of the scaffolds to MG63 cell culture. Therefore, the developed scaffolds are an exciting alternative for application in bone regeneration.

Lightweight, inexpensive and flexible electrodes are required for flexible technological applications. As polymers are generally low cost, flexible and have low density, they are potential candidates for use as flexible electrodes. However, polymers are not conductive and thus cannot be used as electrodes or current collectors. Polymers have been coated by metals/alloys to make them conductive for use in various applications including electromagnetic shielding and sensors. In this work, a flexible electrode was successfully fabricated by electrodeposition of Cu and Ni on polyester fabric for an energy storage application. The growth of metals was carried out in non-aqueous ionic liquid electrolyte, with the deposition condition of Cu and Ni studied by means of cyclic voltammetry. Non-electrochemical (FTIR, XRD, SEM and EDAX) characterizations of the metal-coated polyester are also presented. Modified flexible electrodes were transferred to an alkaline electrolyte for electrochemical characterization. The specific capacitance of Cu- and Ni-coated polyester reached 33.4 F/g and 50.2 F/g at the same scan rate of 5 mV/s. These results suggest an inexpensive and straightforward method for the fabrication of a flexible electrode for energy storage applications.

Neutron scattering is one of the most useful methods of studying the structure of matter, with applications to biomedical, structural, magnetic and energy-related materials. Neutron-scattering instruments are installed around research reactors or accelerator-based neutron sources, and neutron guides are critical components of these facilities. They are neutron-transport optical devices consisting of state-of-the-art mirrors often tens of meters long. Here we demonstrate a novel fabrication method of all-metallic neutron guides and axisymmetric mirrors by electroplating from precision mandrels. The process allows for the fabrication of single-piece all-metal guides of prismatic and axisymmetric shapes. We also demonstrate supermirror guides and axisymmetric focusing supermirrors produced with the same technology. We present the fabrication and tests of the multilayer-coated replicated guides and optic and show that the mandrel is reproduced with high fidelity and reliability. Such supermirror optics will provide game-changing improvements in neutron techniques.

To improve the corrosion resistance and to increase the hardness of copper substrate in marine environment, the Cu-Ni/Ni-P composite coatings were prepared on the copper substrate using the galvanostatic electrolytic deposition method. The deposition current densities were explored to find the optimized deposition conditions for forming the composite coatings. Corrosion resistance properties were analyzed using the polarization curves and electrochemical impedance spectroscopy (EIS). Considering the corrosion resistance and hardness, the −20 mA/cm2 was selected to deposit Cu-Ni coatings on copper substrate and the −30 mA/cm2 was selected to deposit Ni-P coating on the Cu-Ni layer. The Cu-Ni/Ni-P composite coatings not only exhibited superior corrosion resistance compared to single Cu-Ni coating in 3.5 wt.% NaCl solution, but also showed much better mechanical properties than single Cu-Ni coating.

We continue to investigate the design, synthesis, and characterization of electrically and ionically active conjugated polythiophene copolymers for integrating a variety of biomedical devices with living tissue. This paper will describe some of our most recent results, including the development of several new monomers that can tailor the surface chemistry, adhesion, and biointegration of these materials with neural cells. Our efforts have focused on copolymers of 3,4 ethylenedioxythiophene (EDOT), functionalized variants of EDOT (including EDOT-acid and the trifunctional EPh), and dopamine (DOPA). The resulting PEDOT-based copolymers have electrical, optical, mechanical, and adhesive properties that can be precisely tailored by fine tuning the chemical composition and structure. Here we present results on EDOT-dopamine bifunctional monomers and their corresponding polymers. We discuss the design and synthesis of an EDOT-cholesterol that combines the thiophene with a biological moiety known to exhibit surface-active behaviour. We will also introduce EDOT-aldehyde and EDOT-maleimide monomers and show how they can be used as the starting point for a wide variety of functionalized monomers and polymers.

Nano-forms of copper oxides (CuO and Cu2O) are potential candidates in the field of energy conversion and storage. Low temperature and controlled growth of three-dimensional nanostructured hierarchical assembly of CuO over Cu2O is reported here with demonstrated advantage in energy conversion and storage applications. Electrodeposited Cu2O is partially oxidized in an alkali bath to two different forms of hierarchical nanostructures (HNS): CuO/Cu2O and CuO:Cu(OH)2/Cu2O. Randomly oriented nanorods and nanoflakes with high surface area tussock-like nanostructure are formed during oxidation at room and at elevated temperatures, respectively. The nanoflake morphology exhibits a high surface area of 85.82 m2/g and sufficient ion percolation pathways, leading to an efficient electrode–electrolyte interface for electrochemical energy devices. A favorable conduction and valence band alignment in the HNS with respect to water redox level along with fast electron diffusion time of 0.8 μs make it an ideal photocathode.

Nowadays, hierarchical materials have received tremendous interests because of their unique physical and chemical properties. In this article, a novel and facile particle aggregation method was used to fabricate vertically aligned diamondoid nanowires and hierarchical branched nanowire cluster array by using an electrophoresis template method. Triamantane, a three-cage diamondoid, was applied as raw material in current research. Diamondoids are nanometer-sized, hydrogen-terminated diamond-like, saturated hydrocarbons, which process great potential in nanotechnology due to biocompatibility and ultrahard nature. By electrophoresis template method, triamantane molecules dissolved in toluene were transferred into a porous alumina template by electric field and form the one-dimensional (1D) nanostructure with high aspect ratio. After that, a two-step thermal treatment was applied to the nanowires to achieve hierarchical branched nanowires. The surface morphologies of triamantane nanowire array with different treatments were characterized by scanning electron microscopy. This approach opens a new avenue for mass production of the vertically aligned diamondoid nanowires and hierarchical branched nanowire cluster arrays.

La3+-doped BaSnO3 microtubes (La3+–BaSnO3) have been synthesized by electrospinning method, and the influence of La3+ content on the sensing properties of BaSnO3 for detection of formaldehyde vapor has been investigated. The as-prepared materials have been characterized using XRD, SEM, DSC, XPS, and UV-Vis. The La3+–BaSnO3 sample doped with 4 wt% La exhibited a response as high as 220 to formaldehyde vapor (1000 ppm concentration) along with a very low detection limit of 0.1 ppm at 270 °C, whereas at 140 °C, it exhibited a response of 80 and detection limit of 1 ppm. In addition, the sensor showed excellent selectivity of 57 to formaldehyde at 140 °C when compared with other vapors. Further, the sensor also showed good repeatability and stability over a long period of time suggesting its strong potential as a commercial formaldehyde sensor.

Highly dense zirconia dental ceramic coatings were fabricated by aqueous electrophoretic deposition (EPD) and subsequently sintered between 1250 and 1450 °C. Microstructural examination revealed that aqueous EPDZrO2 coatings possessed a tetragonal phase structure and the grain size increased with increasing sintering temperature. Nanoindentation study proved that the aqueous EPDZrO2 coating also had excellent mechanical properties. The effect of different applied loads on hardness and elastic modulus of the 1350 °C-sintered sample at room temperature was investigated by the method of progressive multicycle measurement nanoindentation. The simulative experiment proved that hardness of aqueous EPDZrO2 exhibited reverse indentation size effect (ISE) behavior and then displayed the normal ISE response. The analysis indicates that the reverse ISE is attributed to the relaxation of surface stresses resulting from indentation cracks at small loads and normal ISE is caused by geometrically necessary dislocations. The tetragonal–monoclinic stress-induced phase transformation during nanoindentation is the primary cause of dental zirconia failures.

Coupling semiconductors with electrochemical processes can lead to unusual materials, and attractive, practical device configurations. This work examines the reaction mechanism for single-step electrodeposition approach that creates device quality copper-indium-selenide (CISe) films with either polycrystalline or nanocrystalline morphologies on Cu and steel foils, respectively. The polycrystalline CISe film grows from In3+/Se4+ solution on Cu foil as Cu→ CuxSe→ CuInSe2; it may be used in standard planar pn devices. The nanocrystalline CISe film grown from Cu+/In3+/Se4+ solution follows the CuSe(In)→ CuInSe2→ CuIn3Se5 sequence. The latter approach leads to naturally ordered, space-filling nanocrystals, comprising interconnected 3-dimensional network of sharp, abrupt, p-CISe/n-CISe bulk homojunctions with extraordinary electro-optical attributes. Sandwiching these films between band-aligned contact electrodes can lead to high performance third generation devices for solar cells, light emitting diodes or photoelectrodes for fuel cells. Both approaches produce self-stabilized CISe absorbers that avoid recrystallization steps and can be roll-to-roll processed in simple flexible thin-film form factor for easy scale-up.

Neural electrodes have been widely used to monitor neural signals and/or deliver electrical stimulation in the brain. Currently, biodegradable and biocompatible materials have been actively investigated to create temporary electrodes that could degrade after serving their functions for neural recording and stimulation from days to months. The new class of biodegradable electrodes eliminate the necessity of secondary surgery for electrode removal. In this study, we created biodegradable, biocompatible, and implantable magnesium (Mg)-based microelectrodes for in vivo neural recording for the first time. Specifically, conductive poly-3,4-ethylenedioxythiophene (PEDOT) was first deposited onto Mg microwire substrates by electrochemical deposition, and a biodegradable insulating polymer was subsequently sprayed onto the surface of electrodes. The tip of electrodes was designed to be conductive for neural recording and stimulation, while the rest of electrodes was insulated with a polymer that is biocompatible with neural tissue. The impedance of Mg-based microelectrodes and their performance during neural recording in the auditory cortex of a mouse were studied. The results first demonstrated the capability of Mg-based microelectrodes for in vivo recording of multi-unit stimulus-evoked activity in the brain.

The energy density of electrodeposition reactions makes them attractive for energy storage. Although its scientific inquiries nearly date back to the inception of electrochemistry, its behavior at microscopic dimensions (relevant to battery application) is mysteriously uncontrollable. We examine experimental reports of singular spatiotemporal evolutions with a hope to identify universality in deposition patterns. We conclude that a macroscopic mass transport instability cannot account for various growth morphologies and alludes to poorly understood materials interplay at smaller scales. We summarize representative characteristics of electrodeposition to encourage mechanistic investigations.

Developing metal-based composite coatings with improved mechanical properties and good corrosion resistance has been an attractive research topic in recent years. Graphene (Gr), as a new type of two-dimensional (2D) carbon nanomaterial with excellent physical, chemical and mechanical properties, can be used as a reinforcement to improve hardness, tensile strength, wear and corrosion resistance of metal-based composites. There have been substantial efforts focused on the fabrication of metal-Gr composite coatings via various approaches. Electro-deposition is an effective electrochemical method with wide range of advantages, such as a fast deposition rate, simple set-up with large scale production and relatively low cost. This overview covers the previous research and development studies on metal-Gr composite coatings using electro-deposition method and the resulting properties. In addition, recent work in this area which provides a developed process with industrial production perspective, is discussed.

Historically, batteries with lithium metal anodes have been a hazard, as the lithium becomes rough and eventually finely divided during cycling. The promise of higher energy density, however, continues to drive the search for novel approaches to manage this light and reactive material. Significant improvement has been achieved by designing new liquid-electrolyte compositions and interface barriers to stabilize the lithium in traditional batteries, but it is clear that solid-state batteries ensure a higher level of safety and perhaps higher energy density and lifetimes. The materials challenge then is to fabricate a cost-effective solid electrolyte that effectively maintains lithium as a dense uniform metal layer. This article describes the ideal cycling behavior of lithium and progress toward this goal of a solid electrolyte using glassy, ceramic, polymer, and composite electrolytes, as well as the challenges that continue to arise toward long-term, high-rate, and efficient cycling of lithium metal.

Copper growth for the development of electroplating technique as a low-temperature soldering procedure represents a useful method for the formation of metal deposits, allowing modification of the thickness and morphology of the soldering joints. The approach is particularly useful for soldering electronic components to a plastic 3D printed substrate. To accelerate the soldering process hydrogen assisted electroplating (HAE) method was employed at room temperature. The experiments were designed by making a small electrochemical cell around the gap on a printed circuit board (PCB) or a 3D printed conductive track. During the experiment, water electrolysis was observed, which released hydrogen bubbles. The hydrogen bubbles caused the structure of the electroplated layer to be more porous, but with a similar conductivity as solid copper and a remarkable mechanical strength suitable for use as interconnects on an electronic circuit. Our electrochemical data and video recorded images show a fast and reliable copper electrodeposition in less than 1 minute. The morphology of copper deposits on a 3D printed structure was studied with the scanning electron microscopy (SEM). A reliable soldering process was demonstrated for a surface mount light emitting diode (LED) on a PCB. Further experiments are required to optimize the soldering process for faster and more reliable electroplating, particularly for 3D printed substrates.

As an emerging carbon material with advantages of thinnest, ultrahigh strength, superior thermal conductivity and electrical conductivity, graphene (Gr) is called the “black gold” and will have a profound applying potential in the field of materials science and engineering. Many researches concerning preparation of the Cu-Gr composite via various approaches have been reported. However, only few works are related to the electrochemical deposition method. As a simple, low cost, large scale production method, electrodeposition method has been widely used in industry for manufacturing foils involving copper-clad laminate (CCL), printed circuit board (PCB) and the negative current collector of lithium ion battery, where the copper foil not only serve as the carrier of the cathode active material but also play a role in collecting and conducting electrons. In the present article, we review the research progress on preparations and mechanical properties of the Cu-Gr composite foils by electrochemical method, and introduce our recent work in this area. The advancement of the process and the perspective industrial productions are also discussed.

Engineered non-wetting surfaces inspired by biological species are of interest in the industry due to their potential applications such as water repelling, self-cleaning, anti-icing, anti-corrosion, anti-fouling, and low fluid drag surfaces. However, the adoption of non-wetting surfaces in large scale industrial applications has been hampered by synthesis techniques that are not easily scalable and the limited long term stability and wear robustness of these surfaces in service. In this study, we demonstrate a simple, low cost, and scalable electrochemical technique to produce robust composite coatings with tunable non-wetting properties. The composite coatings are composed of an ultra-fine grain nickel matrix with embedded hydrophobic cerium oxide ceramic particles. Comprehensive characterization, including wetting property measurements, electron microscopy, focused ion beam analysis, hardness measurements, and abrasive wear testing were performed to establish the structure-property relationships for these materials. The grain refinement of the nickel matrix contributes to the high hardness of the composites. As a result of the bimodal CeO2 particle size, hierarchical roughness is present on the surface of the composite, leading to remarkable non-wetting properties, even after 720 m of abrasive wear.

Dendritic growth during charging period is one of the main barriers for the rechargeablity of conventional batteries. Additionally this phenomenon hinders the utilization of high energy density metal candidates by limiting the safety and allowable operating condition for these devices. We address the role of square wave pulse on the growth dynamics of dendrites in the continuum scale and large time periods by formulating an analytical criterion. Our dimension-free analysis permits the application our results to a variety of electrochemical systems in diverse scales.

This work presents the synthesis and characterization of TiO2 nanotubes (NTT) with chitosan (CS). In a first stage, electrochemical anodization of titanium foils was used to generate NTT in a membrane-type arrangement. From these experiments, suitable experimental conditions were selected. In a second stage, the synthesized NTT were detached from the titanium foils by sonication. In the third stage, the detached NTT were dispersed in an acid solution containing CS in various concentrations. Finally, the nanotubes-chitosan (NTT/CS) samples were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infrared Spectrometry (FTIR). Our results showed that the NTT presented very regular tube morphology with -OH and Ti-O- functional groups on the surface. The interaction of NTT and chitosan was enhanced by increasing the time of contact during the synthesis of the titanium composites.