Papers by Keyword: Electrodeposition

Abstract: This study investigates the development and application of Ni-W alloy gradient coatings fabricated via electrodeposition as a direct strategy for industrial energy efficiency optimization. An eight-layer graded coating architecture was successfully synthesized on low-carbon steel substrates through a programmed current density sequence (2–16 A/dm²). This approach produced a progressive increase in tungsten content from ~11.3 at.% at the substrate interface to ~21.9 at.% at the surface, achieving a maximum microhardness of 875 HV via combined solid solution strengthening and grain refinement (3.8–12.5 nm). Crucially, the compositional gradient effectively mitigated internal stresses, enabling the deposition of thick (100 µm), crack-free coatings, in contrast to the cracking observed in homogeneous high-W coatings beyond 40 µm. The enhanced durability and surface properties directly address key industrial energy loss mechanisms. Preliminary assessments indicate that the extended component service life can reduce embodied energy consumption for replacements by up to 65%, while the superior surface hardness and lubricity contribute to operational energy savings of 8–15% in transmission systems through friction reduction. These results demonstrate a clear pathway for leveraging advanced surface engineering to achieve significant, quantifiable energy savings in manufacturing operations..

Abstract: Fe-Nd-B Rare earth magnets are widely used in high performance applications but suffer from poor corrosion resistance due to their multiphase microstructure and the preferential dissolution of rare earth rich intergranular phases. In this study, the corrosion behaviour of Fe-Nd-B magnets was investigated and the effectiveness of electroless nickel coatings as a protective solution was evaluated. Microstructural and compositional analyses were combined with potentiodynamic polarisation tests, comparing bare and coated magnets with low alloy steel. Coating adhesion was assessed by pull off testing according to ASTM D4541. The results show that Fe-Nd-B magnets are significantly more susceptible to corrosion than steel, while nickel exhibits a passive behaviour in the investigated environment. Electroless nickel coatings provide effective protection and display adhesion comparable to that measured on steel substrates, demonstrating their suitability for corrosion protection of Fe-Nd-B magnets.

Abstract: Perfluorooctane sulfonate (PFOS), a toxic and persistent pollutant, poses significant environmental and health risks, making its detection crucial. This study developed silver nanoparticle (AgNP)-modified screen-printed carbon electrodes (SPCEs) for on-site PFOS detection and compared them with glassy carbon electrodes (GCEs). AgNPs were electrodeposited at various concentrations (1–9 mM) using amperometry. SEM-EDS confirmed increasing silver deposition with higher AgNO₃ concentrations, and cyclic voltammetry showed enhanced current responses with increased silver content. Differential pulse voltammetry revealed that 5 mM Ag/SPCE achieved the highest PFOS detection signal (Δi = 11.218 µA), demonstrating the effectiveness of AgNP-modified SPCEs for PFOS detection.

Abstract: Through a simple electrodeposition technique, SnO₂/MnO₂ nanocomposite films were directly deposited onto ultrathin stainless-steel (SS) foils for use in electrochemical supercapacitors. The materials were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Electrochemical experiment revealed that the SnO₂/MnO₂ electrodes exhibited a high gravimetric capacitance of 876 F/g at a current density of 1 A/g. Furthermore, an asymmetric supercapacitor was fabricated using the SnO₂/MnO₂ nanocomposite as the positive electrode and activated carbon as the negative electrode. This asymmetric device demonstrated a capacitance of 72.2 F/g at 1 A/g and retained approximately 87.5% of its initial capacitance after 28,000 cycles, highlighting its excellent cycling stability and practical application potential. The combination of high capacitance and robust stability makes this SnO₂/MnO₂ nanocomposite a promising candidate for high-performance supercapacitor electrodes.

Abstract: Aluminum-Air Batteries (AABs) are considered to be an attractive candidate as a energy storage technology due to their abundant raw material availability, high theoretical capacity, energy density, and safety. However, the development of these batteries is hindered by limited energy efficiency, primarily due to the high rate of self-corrosion of the aluminum anode in alkaline solutions, both under open-circuit conditions and during battery discharge. This research aims to enhance the performance of aluminum anodes in AABs by using commercials aluminum alloys as anodes and modifying their surfaces through the electrodeposition of zinc and manganese (Zn-Mn). The electrolyte used in this AAB is an alkaline solution consist of KOH 4M with 0,2M ZnO and 100mg/L CTAB as additive. The results show that electrodeposition was successfully conducted, leading to reduced corrosion rate as observed in linear polarization tests. Furthermore, electrodeposition contributed to increase battery cycle life, capacity discharge and energy discharge, as demonstrated by charge-discharge tests.

Abstract: Aluminum (Al) has emerged to become one of the potential anode materials candidates in metal-based batteries due to its abundant resource, inexpensive cost, good safeness and high theoretical energy density. However, thoughtful challenges have been barrier towards huge progress, including easy aluminum hydroxide formation, low practical voltage, and high corrosion rate. To approach those problems, this article proposes to enhance the electrochemical performance of anode side through electrodeposition of Zn-Mn on aluminum surface. The deposition of Zn-Mn consists of citrate and ethylenediaminetetraacetic acid (EDTA) as complexing agent to control the process rate. The effect of various deposition time, 0, 10, and 30 minutes, will be investigated by linear polarization, linear sweep voltammetry, cyclic voltammetry, and electrochemical impedance spectroscopy measurements. The electrochemical measurement exhibits the deposition effect, minimized the impedance of Al surface and improved the electrochemical reactions. Moreover, the appearance of Zn-Mn layer has prolonged the discharge performance with battery analyzer measurements. Therefore, energy density increased from 1270.52 to 3327.68 mWh g^-1Al and the specific capacity enhances from 2779.908 to 7291.651 mAh g^-1. All the measurements applied 3.5% sodium chloride (NaCl). These results pose the electrical performance enhancement from the anode side, but the development of other sides is also necessary.

Abstract: This article focused on investigating the influence of current density on the morphology and structure of silver nanoparticles (n-Ag) electrodeposited on anodized titanium substrates (denoted as TiO₂/Ti) on the surface. The TiO₂/Ti substrate served as the cathodic electrode placed in an electrolyte solution containing ionic [Ag(NH₃)₂]⁺ complex solution. The n-Ag/TiO₂/Ti samples were synthesized at current densities ranging from 0.2 A/dm² to 0.5 A/dm² for 20 seconds at room temperature. The study performed morphological and surface composition analysis of n-Ag/TiO₂/Ti using Field Emission Scanning Electron Microscopy (FESEM) and X-ray Diffraction (XRD) techniques. Additionally, the study assessed the electrochemical properties using the AutoLab system with Nova 2.1 software, based on Tafel curve measurements to compare the corrosion resistance of the samples before and after modification.

Abstract: The effect of trisodium citrate on the electrodeposition of nickel-copper-molybdenum in sulfate solution was explored in this paper. According to the results of the nickel-copper-molybdenum electrodeposition experiment, adding a certain amount of trisodium citrate into the electrodeposition solution inhibited the hydrogen precipitation reaction and accelerated the crystallization process on the plated surface to a certain extent, thereby improving the cathodic current efficiency. However, no change occurred to the nucleation mode in the process of electrodeposition crystallization, and it was consistent with the theoretical value of instantaneous nucleation before the peak current (t/t_m≤ 1) was reached. The theoretical values of instantaneous nucleation were consistent. The epitaxial growth rate constant K^* of the crystals was reduced after the addition of trisodium citrate into the electrodeposition solution, indicating the inhibitory effect of trisodium citrate on the growth of crystals in the electrodeposition solution. The diffusion coefficient of the nickel-copper-molybdenum ligand ions was reduced as well, suggesting the inhibitory effect of adding trisodium citrate into the plating solution on the cathodic mass-transfer process, which is conducive to promoting its cathodic polarization. Meanwhile, the growth rate of crystals was significantly affected by the applied potential.

Abstract: Failure in manufacturing industries is a worldwide concern and it occurs most often at elevated temperatures and pressure. Acid, gases, and steam are known to be corrosion and stress-induced propagators resulting in incessant catastrophes. More so, material failure can be due to the substrate material used in the coating while substrate failure can further be classified into the substrate morphology, surface chemistry as well as contamination. Thus, the study developed a multifaceted layer of zinc barrier coating via the electrodeposition technique and observe its response by characterizing the developed coating. The mild steel plate, Zn and MnO₂ were procured and characterized according to the ASTM standard. Mild steel of dimension 60×30×2 mm was sectioned and polished using varying sizes of abrasives. The result of the coating thickness showed that Zn-6MnO₂ had a weight gain of 0.30g. Zn-12MnO₂ was observed to have excellent corrosion performance compared to the as-received and the other formulations of Zn-MnO₂ with a corrosion resistance of 2.117 mm/year. The SEM image of Zn-MnO₂ showed aggregates of clustered grains, thus, no possible fracture lines were observed on the coating surface. Zn-12MnO₂ exhibited a hardness value of 252.72 BHN. Additionally, the EDS of the coatings revealed significant elements that helped in the corrosion performance and hardness properties of the coatings. Keywords: Electrodeposition, Corrosion, Zinc barrier coating, Hardness value, EDS analysis

Abstract: Zinc has attracted significant attention in research due to its cost-effective use as an electrodeposited material, effectively protecting various types of steel from corrosion and wear. However, despite its advantages, zinc has limitations in fully guarding steel against corrosion. Recent studies propose that blending zinc with other metals during the coating process can proficiently shield mild steel from deterioration. The motivation for this study stems from recognizing the restrictions of zinc electrodeposition and the limited exploration of zinc multi-facet composite coatings for mild steel. In this study, the electrodeposition technique was employed to apply a coating to mild steel using zinc and nanoparticles of calcium oxide (CaO) and manganese oxide (MnO₂). The coating bath's chemical composition included mass variations of 0-12 g/L for CaO and MnO₂, along with 10 g/L each of boric acid, thiourea, and Na₂SO₄, and 15 g/L of K₂SO₄ and ZnSO₄. The coating process occurred over a twenty-minute period, with a pH of 4.8, voltage set at 3.2V, current density at 1 A/cm², temperature at 47°C, and stirring rate at 200 rpm. Results obtained from the coated mild steel demonstrated that Zn-6CaO-6MnO₂ exhibited the greatest coating thickness at 0.2308 mm, and it showcased impressive corrosion resistance at 2.0618 mm/year. The Zn-CaO-MnO₂ coating displayed a substantial deposit of crystallites in its microstructure, assisted by the presence of manganese, contributing to a smoother surface texture.