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Here, we report about the synthesis of Cobalt‐Copper (CC) mixed oxides prepared by electrodeposition and thermal annealing, and coated with PEDOT:PSS (CCP) for supercapacitor electrodes. The electrodes' morphology and electrochemical performance were investigated by combining XRD, XPS, SEM, cyclic voltammetry, and galvanostatic charge/discharge tests. The initial capacity of the CC electrode was 26 mAh/g at a scan rate of 5 mV/s with a coulombic efficiency of 92 %. The CC electrode featured a capacity retention of 81 % at a constant current density of 1 A/g after 5000 cycles. CCP electrodes slightly reduced the specific capacity but increased both coulombic efficiency and cyclic stability. CCP1 electrode featured a specific capacity of 21 mAh/g at 5 mV/s scan rate with better coulombic efficiency 95 % along with capacity retention of 92.3 % over 5000 cycles. Increasing the amount of PEDOT:PSS lowered the CC electrodes' specific capacity, but significantly improved the capacity retention up to 100 %. [ABSTRACT FROM AUTHOR]

Reduced graphene oxide (RGO)/TiO2 nanocomposite coating was synthesized using electrophoretic co-deposition (EPD) of graphene oxide and TiO2 colloidal suspension. Direct assembly by EPD facilitated the transformation from GO to RGO and resulted in RGO/TiO2 films on Cu substrate. The prepared samples were characterized by X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The obtained results proved the presence of titania nanoparticles and RGO planes in the nanocomposite coatings and the reduction of GO during EPD process. Methylene blue photodegradation experiments showed that the degradation efficiency and the reduction rate of the contact angle increased in nanocomposite coatings by 12% and 15%, respectively. There is a direct correlation between the amount of RGO in the coating and the improvement of the photocatalytic activity and wettability. [ABSTRACT FROM AUTHOR]

Abstract In vacuum infiltration of Ni-based self-fluxing alloy (NiCrBSi) cladding, reinforced with ultrafine WC particles with average particle size (APS) of 0.2–0.4 μm, several plate-like anomalous WC grains were observed with size of greater than 20 μm. To prevent this anomalous grain growth, Cu shells were coated on WC particles. The very low solid state solubility of WC in copper phase at high temperature can lead to no anomalous WC grain growth. Cu shell with a thickness about 30–50 nm was deposited by means of electroless plating on ultrafine WC particles. The microstructural features of Cu-coated carbides and the resultant brazed claddings were characterized by field emission scanning electron microscopy (FESEM) equipped with energy dispersive X-ray spectroscopy (EDS). The evaluation of the brazed cladding revealed a thick ultrafine grained-microstructure with homogeneous grain size distribution, in contrast to the bare WC-based cermet cladding. The hardness of this novel composite cladding was nearly increased up to 1500 HV, which was 40% more than that of the un-coated WC reinforced cladding. The results demonstrated that the resistance against crack initiation and propagation considerably improved by using Cu-coated WC particles in the sintered media. Highlights • To prevent anomalous WC grain growth in Ni based cladding, Cu shell was coated on WC particles by electroless deposition. • The very low solid state solubility of WC in copper phase at high temperature led to no anomalous WC grain growth. • A fine microstructure with homogeneous grain size distribution was obtained in Cu-coated WC reinforced Ni based cladding. • The hardness of this cladding was increased up to 1500 HV, 40% more than that of uncoated WC reinforced Ni base cladding. • The resistance against crack initiation and propagation was considerably improved in Cu-coated WC reinforced Ni based cladding. [ABSTRACT FROM AUTHOR]

Abstract In this study, a novel Ni-P-coated WC/NiCrBSi composite cladding was prepared on a carbon steel substrate through high-temperature vacuum brazing technique with the aim of improving the wear properties of the surface. In order to improve the wettability of WC particles by a liquid phase (NiCrBSi alloy), Ni-P layer was deposited on carbide particles by electroless plating. This layer assisted to fabricate a thick coating with very low porosity, improving adhesion strength between ceramic particles and the matrix. The morphology, crystal structure and microstructure of coated carbides and the resultant composite cladding were characterized by field emission scanning electron microscopy (FESEM) equipped with energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) analysis. Thin electroless plated Ni-P shell with a thickness about 50–150 nm, were coated on WC particles. In the claddings, a uniform and homogenous distribution of WC particles in Ni-based matrix was observed. The pin on disk wear test was carried out to investigate the wear behavior of the fabricated cladding reinforced with and without Ni-P coated WC particles. The results indicated that the resistance against crack initiation and propagation significantly improved by using Ni-P layer in the sintered cladding. This cladding exhibited very low wear weight loss than conventional brazed cladding. Highlights • A thick brazed coating was performed by core-shell powder (ultrafine WC@NiP) and Ni-based alloy as an infiltrant material. • Ni-P shell layer on WC particles improved the adhesion of particles to the Ni-based brazing alloy. • The remaining pore space value was decreased by using WC@NiP, resulting in increased the wear resistance. • The cracking susceptibility was decreased for Ni-based brazed cladding reinforced with Ni-P coated WC particles. [ABSTRACT FROM AUTHOR]

The ordered ferromagnetic-antiferromagnetic alloy nanowires were fabricated successfully by alternating current (AC) electrodeposition into nanoporous anodized aluminum oxide (AAO). The NiMn alloy nanowires were deposited in a simple sulfate bath. Effect of bath composition on Mn content of electrodeposited nanowires as well as the thermal annealing effect on magnetic properties were explored. The magnetic properties of NiMn alloy nanowires were enhanced significantly, compared to corresponding bulk materials. Magnetic parameters, such as coercivity and saturation magnetization were decreased with increasing the Mn content. For thermal annealing process, it was found that these parameters were enhanced with increasing the temperature up to 300C, on the other hand, they were decreased with increasing the temperature to 500C. Moreover, the X-ray diffraction (XRD) patterns revealed that the FCC crystalline structure of Ni turns to an amorphous phase by increasing the Mn content in the nanowires, resulting in a significant reduction in the . [ABSTRACT FROM AUTHOR]

NiGa alloy nanowires were electrodeposited from an acidic sulfate bath into nanoporous anodized alumina oxide (AAO). This template was fabricated by two-step anodizing. The effects of bath composition and current density were explored on the Ga content of electrodeposited nanowires. The Ga content in the deposits was increased by increasing both Ga in the bath composition and electrodepositing current density. The NiGa alloy nanowires were synthesized for Ga content up to 2–4% without significant improving the magnetic properties. Above this threshold Ga clusters were formed and decreased the magnetic properties of the nanowires. For Ga content of the alloy above 30%, the wires were too short and incomplete. X-ray diffraction patterns reveal that the significant increase of Ga content in the nanowires, changes the FCC crystal structure of Ni to an amorphous phase. It also causes a sizeable increase in the Ga cluster size; these both lead to a significant reduction in the coercivity and the magnetization respectively. [ABSTRACT FROM AUTHOR]

• The Ni-Cu foam was decorated with Pd nanoparticles by galvanic replacement method. • The Tafel slope of Ni-Cu/Pd is 72 mV dec−1 which is 94 mV dec−1 less than substrate. • The fractal architecture of Ni-Cu/Pd provided a high surface area (112.5 cm2). • Ni-Cu/Pd requires 134 mV overpotential at the current density of 10 mA cm−2. Fractal Ni-Cu foam with palladium nanoparticles on (Ni-Cu foam / Pd) was prepared by electrodeposition and galvanic replacement method. The results showed that after the fabrication of Pd particles on Ni-Cu foam, the hydrogen evolution reaction (HER) activity of the electrode improved dramatically. The morphology and phase structure of deposited layers were studied by field emission scanning electron microscopy, and X-ray diffraction methods, respectively. In order to investigate the morphology of the coatings in more details, transmission electron microscope was used, which its figures authenticated the presence of Pd nanoparticles on the fractal structures of Ni-Cu. Based on the electrochemical tests in KOH (1.0 M), the Ni-Cu foam / Pd electrode has good electrocatalytic properties, with a low overpotential of 134 mV at 10 mA cm−2 and Tafel slope of 72 mV dec−1. Cyclic voltammetry measurements showed that the Ni-Cu foam/Pd possesses a high electrochemical surface area of 112.5 cm2 that was attributed to the presence of both fractal Ni-Cu foam and Pd nanoparticles. Overall, this study proposes a feasible approach for the fabrication of a highly-porous, super hydrophilic, and scalable electrode with a great performance toward HER. [ABSTRACT FROM AUTHOR]

Thin nanocrystalline amorphous NiTi film was deposited on Si substrate using DC magnetron sputtering. The as-deposited NiTi thin film was crystallized by heat treatment at 500 °C for 1 h. The crystal structure, surface morphology, microstructure and surface chemistry of the deposited films were studied using X-ray diffraction, atomic force microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy (XPS), respectively. Corrosion behaviour was assessed in Ringer’s solution at 37 °C by open circuit potential (OCP), potentiodynamic polarization and electrochemical impedance spectroscopy as a function of exposure time. OCP values indicate that the tendency for the formation of a spontaneous oxide film is greater for the NiTi thin films than the bulk NiTi. Long time exposure to Ringer’s solution was found to have a great effect on the corrosion behaviour of the samples. Significantly low corrosion current density was obtained for the annealed NiTi film from the potentiodynamic polarization curves indicating a typical passive behaviour, but as-deposited film and bulk NiTi alloy exhibited breakdown of passivity at potentials approximately +1.4 V (vs. SCE). XPS showed that the oxide film formed on the annealed NiTi thin film mainly composed of Ti oxides, and no evidence of Ni was found up to 8.2 nm beneath the top surface, suggesting the excellent corrosion resistance of this sample in Ringer’s solution. [ABSTRACT FROM PUBLISHER]