Papers by Keyword: Electrodeposition

Abstract: Tin oxide (SnO₂) holds significance as an n-type semiconductor metal oxide, finding diverse applications across various fields. It has optimal properties as a gas sensing material, fuel cells, batteries, and so on. The main objective of this research is to synthesize SnO₂ thin films at a low-cost, easily replicable method and study its crystallographic properties. Here, the thin film was prepared by electrodeposition using tin sulfate, tartaric acid, and potassium nitrate at 2.1 pH followed by annealing the obtained thin film at 773 K. The whole process was conducted at 300 K without any external DC. The synthesized substrate was crystallographic properties were studied using X-ray diffraction. The average crystallite grain size was evaluated to be around 19 nm with degree of crystallinity close to 48.3%. These outcomes show that the method used to create thin films was in an appropriate direction.

Abstract: Nickel-Phosphorous/diamond coatings were electrodeposited onto steel substrates using a pulse-stirring method. The electrodeposition process involved a solution containing nickel sulphate, phosphorus acid, and diamond particles, resulting in the co-electrodeposition of 4-8 µm of diamond particles into a Ni-P matrix. To investigate the effects of electrodeposition current density on the properties of the Ni-P/diamond composite coating, scanning electron microscopy (SEM), hardness testing, and electrochemical testing were employed. The research findings revealed that higher current density (0.03 A/cm²) led to a denser diamond particle coating with diamond contents of up to 32.70 vol%. Additionally, the Ni-P/diamond coatings achieved a maximum hardness of 2819 ± 12.55 HV_0.1 when fabricated using the current density of 0.03 A/cm². The "pulse-stirring fabrication" method yields a coating with significantly enhanced wear resistance due to incorporating densely packed diamond particles. The intermittent pulses during the fabrication process are crucial for achieving the desired dispersion and adhesion of the diamond particles, leading to a practical and durable wear-resistant coating.

Abstract: The article deals with the pulse electrolysis energy parameters effect on the current efficiency, phase composition and morphology of the cobalt with refractory metals – tungsten and molybdenum galvanic alloys surface. Synthesized coatings corrosion resistance and synthesized coatings catalytic activity testing results in various acidity media are presented. The obtained experimental data for the various composition alloy Co-Mo-W are compared with respective indicators for individual metals. The synergy effect presence due to the alloying elements mutual influence is experimentally established.

Abstract: The demand for flexible and wearable electrochemical sensors has surged due to their low cost and portability. This study produces and characterizes low-cost and environmentally friendly flexible laser engraved graphene/Cu nanoparticles composite materials as a potential electrode for electronic applications. The electrode is fabricated by directly engraving Polyimide substrate using a CO₂ laser machine to produce Laser Engraved Graphene (LEG). The electrode is then modified with copper nanoparticles via a one-step pulse electrodeposition technique to be characterized structurally, mechanically, and electrochemically using SEM, XRD, bending test, electrochemical impedance spectroscopy, and cyclic voltammetry to assess their stability and electrocatalytic activity. The laser irradiation of PI results in 3D porous graphene structure formation that increases electron transfer rate and the electrochemically active surface area. Copper deposition improves the sensitivity of LEG by its high conductivity.

Abstract: Diamond-like carbon (DLC) is widely studied for various applications such as optoelectronics, energy, aerospace, and medicine. It’s hard, chemically inert, and optically transparent. Due to its superior antireflection properties, DLC films are more suited for photovoltaic technology. Here in this work, we report a facile, high speed, and low-cost method of DLC film development from an aqueous solution via electrodeposition. The effect of applied voltage and solution concentration on the properties of DLC film was analyzed. The morphology, shape, and uniformity of the DLCs were analyzed with optical and electron microscopies. The presence of C-H, C-C, and C=C bonds in the DLC films was confirmed from FTIR and Raman spectroscopies. Whereas the optical behavior was analyzed with a UV-Vis-NIR spectrophotometer. The DLC films were deposited at 2.7 V, 4V, 6V, 8V, and 10V, and it was shown that for a fixed electrolyte concentration and electrode spacing, the applied voltage can be adjusted to obtain varying deposition rates. Likewise, the solution concentration was varied in the 2 vol.% to 10 vol.%, and it was demonstrated that by increasing the solution concentration the deposition rate increases. The increase in the deposition rate was evidenced by an increase in the deposition current as well as the roughness of the films. It was noticed that smaller-sized, well-defined, and more uniform DLC films were obtained at lower concentrations and low voltage levels. The band gap was varied between 2.91ev to 3.39ev. It was clearly shown that reflection reduced remarkably after depositing DLC film on the substrate surface. This work demonstrates that DLC film has a potential to utilized as an antireflection layer in photovoltaic application.

Abstract: One of the key challenges for the development of perovskite solar cells lies in the approach toward large-scale fabrication of the active materials that allows for good photovoltaic performance, as well as facile handling. The electrodeposition technique can potentially address such requirements. However, the technique has yet to be investigated in detail and still suffers from low efficiency of the device. In this study, we sought to significantly upgrade the electrodeposition approach by coupling the technique with an external magnetic field in the preparation of high-quality PbI₂ precursor layer and using Li-doped SnO₂ electron transport layer. Our results showed that the magnetic field-assisted electrodeposition yielded good crystallinity of PbI₂ and perovskite. Introducing the Li-doped mesoporous SnO₂ into the device structure resulted in a higher current density of 18.50–18.80 mA cm^-2, which can be attributed to, based on the linear sweep voltammetry, reduced resistance of the electron transport layer from 32.27 to 22.11 Ω cm^-2. Moreover, the carbon-based device prepared using this simple procedure also yielded 5.20% in photoconversion efficiency for 1-cm² active area and 0.45% for 25-cm² active area, all without any significant hysteresis.

Abstract: The reinforced composite coating has been proven to offer outstanding properties and increased component life span in service. Thus, its development has found a significant place in advanced engineering applications. This study aims to reinforce Zinc-Zinc Oxide composite coatings with an organic and sustainable, eco-friendly product, scales of Micropogonias undulatus (M. undulatus) anti-corrosion composite coating, for mild steel protection in service. The coating was developed via the electrolytic deposition route. The effects of the process parameter, deposition time, on the morphology and electrochemical properties were reported. While the Optical Microscope (O.M.) and Scanning Electron microscopy (S.E.M.) equipped with Energy Dispersive Spectroscopy (E.D.S.) were used for structural study, the PGSTAT 30 potentiostat linked to the electrochemical software NOVA 1.8 was used for the corrosion polarisation studies. The result showed excellent coating adhesion, substrate protection and remarkable corrosion resistant attributes with the Zn-ZnO-M. undulatus scales nanoparticulate coatings. The result also revealed that the deposition done at 25 minutes had the best and most enhanced anti-corrosion attributes.

Abstract: A metallic part corrodes when it undergoes electrochemical reactions which cause the surface and structural deterioration of the metal. Through electroplating, metallic components can be protected from corrosion by coating them with Zn-Ni alloys. This study examined the electrodeposition of a Zn-Ni alloy film on a steel substrate from a chloride bath containing ethylene-diamine-tetraacetic acid (EDTA). A Pourbaix diagram using the OLI software was used to determine the stability of the Zn-Ni plating bath and the suppression of hydrogen evolution reaction (HER). Comparing the composition of Zn-Ni coating deposited in the EDTA bath with the pure Zn-Ni coating, the EDTA bath yielded higher deposition thickness and an average crystallite size reduction. The Zn-Ni coating deposited from the EDTA bath has a lower dissolution rate and better corrosion resistance properties than the non-EDTA bath. Polarization tests exhibited that the Zn-Ni alloy deposited from 0.119 mol/l EDTA bath at 20 mA/cm² current density showed lower corrosion current (Icorr) and more positive corrosion potential (Ecorr). Atomic force microscopy (AFM) and Vickers microhardness testing were used to characterize the morphological properties, topographic structures, and microhardness of Zn-Ni coatings.

Abstract: Ni-TiN/Si₃N₄ composite coatings on tungsten carbide were prepared by electrodeposition. The influences of electrodeposition temperature at 35 – 45 °C on coating microstructure and its impact to the mechanical and tribology properties were investigated to optimize the process parameter. A compact morphology of coatings gradually increased with increasing electrodeposition temperature that was addressed to the finer Ni crystallite size which resulted from co-deposition of TiN and Si₃N₄ particles. The finer crystallite size caused the increase of coating hardness with the highest (8.86 GPa) was achieved for the sample deposited at 45 °C. However, from the result of wear rate test, it was shown that the lowest wear rate (28.5 μm) was observed on the sample deposited at 40 °C.

Abstract: High energy and power density, good life cycle are highly sought in fabricating supercapacitors. In this study, Co₃O₄ was successfully deposited on nickel foam via electrochemical route. The nucleation of cobalt hydroxide and its transformation to oxide were monitored using chronoamperometry and cyclic voltammetry. Changes in current density and detected redox peaks suggest the electrochemical activity of Co₃O₄ in an alkaline media. A specific capacitance 1291 F/g at current density of 2.5 mA/cm was achieved showing the supercapacitive property of the synthesized Co₃O₄. EDX results confirms the incorporation of samarium to cobalt oxide. Furthermore, scanning electron microscopy (SEM) reveals the evolution of nanosheets to nanoflowers as the electrochemical synthesis parameters were varied. The effect of morphology on the electrochemical activity and performance of Co₃O₄ with Samarium could pave way in developing high energy and power density electrode for supercapacitors.