Search Results (170)

Among the most promising alloys for photovoltaic applications is copper–indium–gallium–selenide (CIGS) because of its enhanced optical properties. This study examines the influence of current density and pulse timing on the electrodeposition of Cu(In, Ga)Se₂ (CIGS) thin films from a dilute electrolyte. It assesses how these parameters affect deposition quality, film characteristics, and device performance. CIGS absorber layers were electrodeposited using a pulsed-current method, with systematic variations in current density and pulse on/off durations in a low-concentration solution. The deposited precursors were subsequently selenized and incorporated into fully assembled CIGS solar cell architectures. Structural characteristics were analyzed by X-ray diffraction (XRD), whereas composition and elemental distribution were assessed by energy-dispersive X-ray spectroscopy (EDS). Optical properties pertinent to photovoltaic performance were evaluated through transmittance and reflectance measurements. The results indicate that moderate current densities, when combined with brief off-times, produce dense, microcrack-free films exhibiting enhanced crystallinity and near-stoichiometric Cu/(In + Ga) and Ga/(In + Ga) ratios, in contrast to films deposited at higher current densities and extended off-times. These optimized pulse parameters also produce absorber layers with advantageous optical band gaps and improved device performance. Overall, the study demonstrates that regulating pulse parameters in attenuated electrolytes is an effective strategy to optimize CIGS film quality and to facilitate the advancement of economical, solution-based fabrication methods for high-performance CIGS solar cells. Full article

Copper has become more important owing to its eco-friendliness and persistent efficacy against infections. Furthermore, copper has benefits such as safety in use and durability. This study aimed to develop and assess the antibacterial efficacy of stainless steel coated with a composite layer, which is nanostructured and incorporates copper, to create antibacterial surfaces with good adherence and good corrosion resistance. The composite coating was produced using anodic oxidation, with an external copper layer applied via pulse electroplating. The homogenous cauliflower-like covering showed important characteristics, like increased surface roughness, boosted surface free energy, reduced contact angle, and higher hardness. Additionally, the adherence between the composite covering and the substrate was exceptional. Electrochemical experiments indicated aggressive corrosion behavior in chloride-containing settings. Antibacterial tests were conducted on four prevalent bacterial strains: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhimurium—microorganisms often linked to healthcare and environmental pollution. The coating exhibited enhanced antibacterial efficacy relative to untreated steel and anodized steel. Results indicated that the composite coating is an effective and possibly cost-efficient method for controlling the surface proliferation of the mentioned pathogens. Full article

In this article, electrodeposited Ni-Al₂O₃ coatings were fabricated on the surface of a cylinder liner to enhance its corrosion resistance. The effect of current density on the surface morphology, phase structure, and corrosion resistance of the Ni-Al₂O₃ coatings was investigated using a scanning electron microscope (SEM), X-ray diffraction (XRD) instrument, and electrochemical workstation, respectively. The observed results show that a dense, flat morphology emerged on the surface of the Ni-Al₂O₃ coatings prepared under a current density of 3.5 A/dm². Furthermore, among three Ni-Al₂O₃ coatings, the Al content of the one prepared under a current density of 3.5 A/dm² was the highest, with a value of 5.4 wt.%. XRD patterns demonstrated that the average nickel grain size of the Ni-Al₂O₃ coatings prepared at 3.5 A/dm² was only 251.6 nm, which was obviously smaller than those deposited under current densities of 2.5 A/dm² and 4.5 A/dm². Meanwhile, the adhesion strength of the Ni-Al₂O₃ coatings prepared under a current density of 3.5 A/dm² was the largest, with a value of 40.9 N. Polarization curves indicated the corrosion potential of the Ni-Al₂O₃ coatings prepared under a current density of 3.5 A/dm² was the highest, with a value of −0.42 V, while the corrosion current density of the coatings fabricated under a current density of 3.5 A/dm² was the lowest, with a value of 2.17 × 10⁻⁷ A/cm². In addition, the corrosive mass loss of Ni-Al₂O₃ coatings manufactured at 3.5 A/dm² was only 2.8 mg, illustrating excellent corrosion resistance. This study could enhance the service life and corrosion resistance of cylinder liners in internal combustion engines. Full article

Novel hybrid semiconducting thin films comprising CdSe with the addition of nitrogen-doped carbon dots (NCDs) were developed onto titanium substrates using a one-step electrocodeposition technique. The deposition took place using an acidic aqueous electrolytic bath containing hydrothermally produced ΝCDs under direct and pulse current regime. The specimens were studied using XRD, SEM-EDS, and UV-Vis spectroscopy techniques to determine their microstructural characteristics, surface morphology and composition and the energy gap, respectively. Their photochemical behavior was studied utilizing a photoelectrochemical cell (PEC). Variations in physical properties, along with significantly improved photoelectrochemical responses, were observed for the NCD-infused semiconductive thin films compared to their plain CdSe counterparts. These variations were highly affected by the incorporation rate of the NCDs in each thin film, as well as the imposed electrolysis conditions. Full article

Ni/ZrO₂ composite coatings are increasingly employed, yet the influence of organic additives under a pulse current regime on their electrodeposition remains insufficiently addressed. This study investigates the combined effect of pulse frequency (0.01–100 Hz) and coumarin concentration (0–2 mmol L⁻¹) on the co-deposition behavior, microstructure, and properties of Ni/ZrO₂ coatings electrodeposited from a Watts-type bath. The structural, morphological, and compositional features were analyzed through SEM/EDS, FE-SEM, and XRD, while microhardness and surface roughness were determined to establish processing–structure–property correlations. The results revealed that coumarin acts as an effective levelling agent, promoting smoother and finer-grained coatings while modifying ZrO₂ incorporation and Ni crystallographic orientation. Increasing coumarin concentration led to a notable refinement of nickel crystallites and a rise in hardness, reaching values close to 650 HV under optimal PC conditions. Pulse frequency was found to strongly influence the microstructural characteristics and particle co-deposition rates, particularly at low frequencies, where a balance between additive adsorption and current modulation favored particle incorporation and enhanced the microhardness. It was demonstrated that the synergistic control of pulse parameters and coumarin concentration enables the design of Ni/ZrO₂ composite coatings with tailored microstructure, low roughness, and superior hardness for demanding applications. Full article

With continuous breakthroughs in electrochromic technology, tungsten trioxide (WO₃) thin films, as a core material in this field, are rapidly expanding their applications in smart windows, anti-glare automotive rearview mirrors, and adaptive optical lenses. Owing to its excellent electrochromic properties—including high optical modulation, short switching times, and high coloration efficiency—WO₃ has become a research focus in the field of electrochromic devices. This review takes WO₃ thin films as the research subject. It begins by introducing the crystal structure of WO₃ and the ion/electron co-intercalation-based electrochromic mechanism and explains two key performance parameters for evaluating electrochromic properties: optical modulation amplitude and coloration efficiency. Subsequently, it provides a detailed review of recent advances in the preparation of WO₃ thin films via physical methods (including sputtering deposition, evaporative deposition, and pulsed laser deposition) and chemical methods (including hydrothermal, sol–gel, and electrodeposition methods). A systematic comparison is made of the microstructure and electrochromic performance (optical modulation amplitude and coloration efficiency) of films prepared by different methods, and the interaction between WO₃ film morphology and device structure is analyzed. Finally, the advantages and challenges of physical and chemical methods in tuning film properties are summarized, and the outlook of their application prospects in high-performance electrochromic devices is given. This review aims to provide guidance for the selection and process optimization of WO₃ thin films with enhanced performance for applications such as smart windows, anti-glare rearview mirrors, and adaptive optical systems. Full article

Aluminum powder is the most commonly used metal fuel in the industry of explosives and propellants. The research progress in preparation technology, reactivity and application of nano-aluminum in explosives and propellants is systematically reviewed in this paper. The preparation technology of nano-aluminum powder includes mechanical pulverization technology (such as the ball milling method and ultrasonic ablation method, etc.), evaporation condensation technology (such as the laser induction composite heating method, high-frequency induction method, arc method, pulsed laser ablation method, resistance heating condensation method, gas-phase pyrolysis method, wire explosion pulverization method, etc.), chemical reduction technology (such as the solid-phase reduction method, solution reduction method, etc.) and the ionic liquid electrodeposition method, each of which has its own advantages. Some new preparation methods have emerged, providing important reference value for the large-scale production of high-purity, high-quality nano-aluminum powder. The reactivity differences between nano-aluminum powder and micro-aluminum powder are compared in the thesis. It is clear that the reactivity of nano-aluminum powder is much higher than that of micro-aluminum powder in terms of ignition performance, combustion performance and reaction completeness, and it has a stronger influence on the detonation performance of mixed explosives and the combustion performance of propellants. Nano-aluminum powder is highly prone to oxidation, which seriously affects its application efficiency. In addition, when aluminum powder oxidizes or burns, a surface oxide layer will be formed, which hinders the continued reaction of internal aluminum powder. In addition, nano-aluminum powder may deteriorate the preparation process of explosives or propellants. To improve these shortcomings, appropriate coating or modification treatment is required. The application of nano-aluminum powder in mixed explosives can improve many properties of mixed explosives, such as detonation velocity, detonation heat, peak value of shock wave overpressure, etc. Applying nano-aluminum powder to propellants can significantly increase the burning rate and improve the properties of combustion products. It is pointed out that the high reactivity of nano-aluminum powder makes the preparation and storage of high-purity nano-aluminum powder extremely difficult. It is recommended to increase research on the preparation and storage technology of high-purity nano-aluminum powder. Full article

High-performance electrical contact materials are crucial for electric power systems, new energy vehicles, and rail transportation, as their properties directly impact the reliability and safety of electronic devices. Enhancing these materials not only improves energy efficiency but also offers notable environmental and economic advantages. However, traditional composite contact materials often suffer from poor dispersion of the reinforcing phase, which restricts further performance improvement. Graphene (G), with its unique two-dimensional structure and exceptional electrical, mechanical, and tribological properties, is considered an ideal reinforcement for metal matrix composites. Yet, its tendency to agglomerate poses a significant challenge to achieving uniform dispersion. To overcome this, the study introduces a dual approach: modulation of the zeta potential (ζ) in the silver-plated liquid to enhance G’s dispersion stability, and concurrent optimization of the composite electrodeposition process. Experimental results demonstrate that this synergistic strategy enables the uniform distribution of G within the silver matrix. The resulting silver–graphene (Ag-G) composite coatings exhibit outstanding overall performance at both micro and macro levels. This work offers a novel and effective pathway for the design of advanced electrical contact materials with promising application potential. Full article

A novel process for the synthesis of binder-free, porous nickel/polythiophene-functionalized sulfur (Ni/S-PTh) composite cathodes for lithium–sulfur (Li–S) batteries is introduced in this paper. Initially, a polyvinyl butyl polymer scaffold is 3D printed, then coated with a graphite-based conducting layer, and, finally, it is pulse-plated for nickel deposition to produce a high-surface-area, mechanically stable current collector. S-PTh particles are afterwards co-deposited into the Ni matrix through composite electrodeposition. After the dissolution of the polymer template, the resulting self-standing electrodes still maintain porous structure with uniform sulfur distribution and a distinct transition between the dense Ni layer and the Ni/S-PTh composite layer. Electrochemical characterization of the Ni/S-PTh composite cathodes by galvanostatic cycling at C/10 rate results in an initial specific discharge capacity of ~1120 mAh·g⁻¹ and a specific capacity of ~910 mAh·g⁻¹ after 200 cycles, resulting in a high capacity retention of ~81 %. For our novel approach, no steps at high temperatures or toxic solvents are involved and the need for polymer binders and conductive additives is avoided. These results demonstrate the potential of composite electrodeposition in combination with 3D printing for producing sustainable, high-performance sulfur cathodes with tunable architecture. Full article

In this work, the effect of the applied current density (J) during galvanostatic anodization of titanium (5–30 mA/cm²) on the TiO₂ morphology and its influence on the SERS performance after pulsed silver electrodeposition (5 mA/cm², 400 cycles, 50 ms ON/250 ms OFF) was evaluated. SEM micrographs showed a transition from nanotubes with scarce nanograss to a dense coverage of nanograss over the surface, which conditioned the formation and distribution of silver nanoparticles and dendrites. Using methylene blue as a probe molecule, the substrate anodized at 15 mA/cm² exhibited the highest SERS intensity, attributed to the high density of hot spots vertically distributed in the 3D dendrites. The optimized substrate demonstrated detection of methylene blue down to 1 × 10⁻¹¹ M and reached an analytical enhancement factor of 7 × 10⁷, highlighting its strong performance. These results establish galvanostatic anodization as a novel and effective route for designing reproducible and scalable TiO₂/Ag substrates with high SERS response. Full article

An electrochemical aptamer sensor for the sensitive detection of aflatoxin B₁ (AFB₁) in corn samples was developed using nanocomposites loaded with copper nanoparticles (CuNPs) on zeolitic imidazolate framework-8 (ZIF-8), which were modified on a glassy carbon electrode (GCE). The CuNPs@ZIF-8 nanocomposites served as modifying materials for electrodes, exhibiting a high specific surface area and excellent compatibility with aptamers, thereby enhancing the electron transfer rate and increasing the aptamer loading and immobilization efficiency. The electrochemical properties before and after modification were investigated and validated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques, while the sensor’s performance was analyzed through quantitative detection via differential pulse voltammetry (DPV). Furthermore, various conditions, including the volume of ZIF-8 dispersion, electrodeposition time of copper nanoparticles, aptamer concentration, and AFB₁ incubation time, were optimized. The results indicated that the sensor exhibited a wide linear range (10.0 to 1.0 × 10⁶ pg/mL), with a lower limit of detection (LOD) of 1.13 pg/mL under optimized conditions, outperforming other reported aptamer sensors. The spiked recoveries in corn samples ranged from 96.663% to 105.72%. In conclusion, this sensor presents a novel solution for low-cost and high-sensitivity detection of AFB₁. Full article

This study reports the development of a simple and sensitive electrochemical sensor based on activated screen-printed electrodes modified by electrodeposition of nickel(II) tetrasulfonated phthalocyanine film (poly-NiTSPc), denoted SPE-A-polyNiTSPc, for the direct determination of BPA in landfill leachate samples. BPA concentrations in raw landfill leachate solutions and in residual solutions after a reverse osmosis (RO) treatment were determined, using differential pulse voltammetry (DPV) on SPE-A-polyNiTSPc, to be 29.7 mgL⁻¹ and 6.4 µgL⁻¹, respectively. The obtained BPA concentrations were very close to those found by the accredited lab in the same samples, which were 29.6 mgL⁻¹ and 6.0 µgL⁻¹, respectively. The applicability of SPE-A-polyNiTSPc for BPA bioremediation was investigated in landfill leachate samples using Trichoderma harzianum fungus in a microbial fuel cell (MFC), where the kinetics data were modeled. The first results showed an IC₅₀ of 175 mgL⁻¹ BPA, indicating that the inhibition factor could be negligeable for MFC experiments at 30 mgL⁻¹ BPA. The biodegradation kinetics was found to be of first order, with a kinetic constant of 0.795 h⁻¹ at 22 °C and a half-degradation time of 0.872 h for an initial concentration of 29 mgL⁻¹. The developed MFC displayed higher stability, offering a maximum power of 100 mWm⁻³. Full article

Lifetimes of Ag/AgCl electrodes determine whether it is possible to monitor the concentration of chloride ions in marine concrete structures. A novel manufacturing method, pulse current electrodeposition at a low current density, was proposed to prepare the long-lifetime Ag/AgCl electrode. Influences of electrodeposition duration were investigated on the Nernst response, exchange current density, and lifetime of Ag/AgCl electrodes, and the properties were also compared to those of the ones electrodeposited by applying constant currents. Ag/AgCl electrodes prepared with the pulse current exhibited a wider potential response, a higher exchange current density, and a longer lifetime than those prepared by the constant current under the same equivalent charge transfer conditions. AgCl film on the electrode prepared with the pulse current displayed a thicker layer, a lower density of micropores, a higher Cl/O ratio, and a lower Ag/Cl ratio than those of its counterpart electrodeposited by applying the constant current. The lifetime of the Ag/AgCl electrode was mainly determined by the thickness of AgCl films in the concrete environment. The lifetimes of the Ag/AgCl electrode, which was prepared with a 0.1 mA cm⁻² pulse current for 15 h, were 420 h in pore solution and more than 3500 h in mortar, respectively. In addition, the potential of this Ag/AgCl electrode did not show any significant decrease after 3500 h in the mortar without Cl⁻. The results suggest that pulse current electrodeposition is an effective method to improve the lifetimes of Ag/AgCl electrodes in concrete. Full article

The aim of the present study is to investigate the influence of Nickel–Hexagonal Boron Nitride (Ni-hBN) nanocomposite coatings, deposited using the pulse reverse current electrodeposition technique. This experimental study focuses on assessing the tribological and corrosion properties of the produced coatings on the SS304 substrate. The microhardness of the as-deposited (AD) sample and heat-treated (HT) sample were 49% and 83.8% higher compared to the control sample. The HT sample exhibited a grain size which was approximately 9.7% larger than the AD sample owing to the expansion–contraction mechanism of grains during heat treatment and sudden quenching. Surface roughness reduced after coating, where the Ni-hBN-coated sample measured a roughness of 0.43 µm compared to 0.48 µm for the bare surface. The average coefficient of friction for the AD sample was 42.4% lower than the bare surface owing to the self-lubricating properties of nano hBN. In particular, the corrosion rate of the AD sample was found to be 0.062 mm/year, which was lower than values reported in other studies. As such, findings from the present study can be particularly beneficial for applications in the automotive and aerospace industries, where enhanced wear resistance, reduced friction, and superior corrosion protection are critical for components such as engine parts, gears, bearings and shafts. Full article

Electro-oxidation of ammonia has emerged as a promising route for sustainable energy conversion and pollutant mitigation. In this study, we report the facile fabrication of dendritic Cu@Pt core–shell nanostructures electrodeposited on pencil graphite, forming an efficient electrocatalyst for the ammonia oxidation reaction (AOR). The designed electrocatalyst exhibited high catalytic activity towards AOR, achieving high current density at very low potentials (−0.3 V vs. Ag/AgCl), with a lower Tafel slope of 16.4 mV/dec. The catalyst also demonstrated high electrochemical stability over 1000 potential cycles with a regeneration efficiency of 78%. In addition to catalysis, Cu@Pt/PGE facilitated very sensitive and selective electrochemical detection of ammonia nitrogen by differential pulse voltammetry, providing an extensive linear range (1 μM to 1 mM) and a low detection limit of 0.78 μM. The dual functionality of Cu@Pt highlights its potential in enhancing ammonia-based fuel cells and monitoring ammonia pollution in aquatic environments, thereby contributing to the development of sustainable energy and environmental technologies. Full article