A comprehensive analysis was conducted to examine the crystal phase composition, surface and cross-section morphology, elemental composition, thickness, and corrosion resistance of coatings. X-ray diffraction (XRD) was employed to investigate the texture and crystal phase of the materials while scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were utilized to assess the surface and cross-section structure. Additionally, electrochemical techniques were employed to evaluate the corrosion performance. Compared to DC electroplating, the corrosion potential of pulsed galvanized ferroalloy alloy coating increased from −1031 mV to −1008 mV, and the corrosion current density decreased from 3.122 × 10⁻⁵ A∙cm⁻² to 0.321 × 10⁻⁵ A∙cm⁻². Moreover, the corrosion rate value of the coating obtained by the pulse rectifier (0.386 × 10⁻⁵ g m⁻² h⁻¹) was lower than that obtained by the DC power supply (3.75 × 10⁻⁵ g m⁻² h⁻¹). Additionally, pulsed electrodeposition reduced the iron content of the coating by 0.7%, thereby enhancing its corrosion resistance and flatness. The impedance parameters of the zinc–iron alloy coating acquired through the 30% duty cycle monopulser process exhibit superior performance compared to DC electroplating. Evidently, the monopulse coating’s structure enhances crystal packing density, augments coating thickness, improves adhesion to the substrate interface, and optimizes grain distribution uniformity. These factors are crucial determinants of the corrosion behavior exhibited by Ze–Fe coating.

In this study, pre-treated low-carbon steel substrates were electroplated with Zinc–Nickel (ZN) alloy composite coatings enhanced by the incorporation of nano-silicon dioxide (SiO₂) particles in an alkaline solution. ZN deposits with varying concentrations of nano-SiO₂—specifically, 1, 2, 3, 5, and 10 wt%—were achieved by adjusting the ratio between the nano-SiO₂ and ZN alloy electroplating solutions. The influence of the nano-SiO₂ content on both the quality of the coating and its corrosion behavior was investigated in detail. Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and an atomic force microscope (AFM) were utilized to assess the surface, cross-section structure, elemental composition, and thickness of the coatings. Notably, the addition of nano-SiO₂ improved the microstructure of the coating, leading to a reduction in grain size as well as enhancements in uniformity and density while revealing that co-deposition reached an optimal concentration at 3 wt% nano-SiO₂. The corrosion behavior of coated specimens was evaluated through electrochemical impedance spectroscopy (EIS) and polarization techniques within a 3.5 wt% NaCl solution serving as a corrosive medium. Specifically, for typical prepared coatings, the corrosion current density decreased from 1.410 × 10⁻⁴ A·cm⁻² to 5.762 × 10⁻⁶ A·cm⁻², which is a remarkable reduction by one to two orders of magnitude relative to the SiO₂-free coatings mentioned previously. These findings provide a straightforward approach for selecting 3 wt% nano-SiO₂ as an effective additive in ZN composite coatings.

In this work, MnO₂/TiO₂ coating on metallic porous titanium was prepared through a hydrothermal-based chemical method, followed by a chemical precipitation reaction of KMnO₄ and MnSO₄ aqueous solutions. The surface of the MnO₂/TiO₂/Ti was uniform and compact, with a high load capacity. The corrosion resistance and electrochemical properties of the MnO₂/TiO₂/Ti coating were investigated in comparison with those of pure Ti and TiO₂ coatings. Cyclic voltammetry and constant current charge–discharge measurements showed that the MnO₂/TiO₂/Ti electrode presented good electrochemical performance. The MnO₂/TiO₂/Ti electrode had the highest capacitor performance compared to the other electrodes, and the nano-MnO₂ coating significantly decreased the corrosion current densities. The nano-MnO₂ coating exhibited excellent anti-corrosion properties at room temperature and better capacitance performance compared with pure Ti and TiO₂ coatings. After surface modification, TiO₂/Ti-coated MnO₂ had better electrochemical behavior and significantly improved corrosion resistance than the TiO₂/Ti nanocomposites. Its specific capacitance reached 314 F/g, which was 3.5 times that of the TiO₂/Ti electrode material.

The passivation of zinc alloy coating was achieved through the utilization of both silicate and trivalent chromium passivation systems, employing a specific process formula consisting of Co(NO₃)₂ at a concentration of 2.5 g/L, C₇₆H₅₂O₄₆ at 3 mL/L, Na₂SiO₃ at 25 g/L, C₆H₅Na₃O₇ at 15 g/L, and an appropriate amount of organic accelerator. The composite passivation of silicate and tannic acid was found to be more effective than the trivalent chromium passivation film, as it successfully eliminated the dendrite structure on the coating surface and reduced surface defects. The coordination between negatively charged SiO²⁻ or SiO₂ micelles and Zn²⁺ results in the formation of a passivation film that exhibits lower corrosion current and higher corrosion potential compared to the trivalent chromium passivation film. Additionally, the impedance test fitting results indicate that the silicate passivation film possesses a higher resistance value. Overall, the proposed silicate passivation system presents a viable alternative to the toxic chromate passivation system, offering non-toxicity and superior protective performance relative to the trivalent chromium passivation system.

Self-assembled nanocomposites are attracting considerable attention owing to their controllable architectures and self-assembly processes, as well as the increase in worldwide environmental effects and energy needs. Further understanding of the self-assembly procedure for improving environmental and energy applications would advance the design and manufacture of nanomaterials for various applications. These materials can be grouped into major categories for various application fields, including powder photocatalysts, membrane photocatalysts, and thin-film thermoelectric nanomaterials. These self-assembled nanomaterials can be used for environmental and energy applications, such as wastewater purification, hydrogen production by water splitting, energy storage, and energy harvesting. In this review, a brief introduction to the definitions and classifications of self-assembled nanocomposites is provided. We aim to provide a summary of the recent research related to self-assembled nanocomposites and nanostructures used for environmental and energy applications. Moreover, typical examples and discussions are aimed at demonstrating the advantages of self-assembled nanostructures. At the end of each section, the structural properties and the application of the nanocomposite or nanostructure are summarized. Finally, we provide perspectives for future research on the design and fabrication of self-assembled nanocomposites and nanostructures.

The novel pyridine oxime-based complexing agents 2-pyridinecarboxaldehyde oxime, 2-acetylpyridine ketoxime and 2-pyridine amidoxime were synthesized for alkaline Zn-Ni alloy electrodeposition, outperforming conventional citrate/TEPA systems in corrosion resistance and microstructural control. The N,O-bidentate chelation mechanism governs metal ion reduction kinetics via diffusion-limited pathways, enabling γ-phase Ni₅Zn₂₁ intermetallic formation and nanocrystalline refinement. Electrochemical and microstructural analyses demonstrate suppressed random nucleation and hydrogen evolution side reactions, leading to enhanced charge transfer resistance and reduced corrosion current density. Notably, 2-pyridine amidoxime achieves ultrasmooth surfaces through defect-free nanocluster growth, while 2-pyridinecarboxaldehyde oxime maximizes γ-phase crystallinity. The synergy between grain boundary density and surface integrity establishes a dual protection mechanism combining barrier layer formation and active dissolution suppression. This work advances microstructure engineering via coordination chemistry, offering a breakthrough over traditional zincate electroplating for high-performance anti-corrosion coatings.