Effect of the Addition of Molybdenum on the Structure and Corrosion Resistance of Zinc–Iron Plating

Zn–Ni plating is indispensable in various industries because of its high corrosion resistance. However, Ni has been reported to trigger allergies; thus, an alternative Ni-free plating is desired. Zn–Fe plating is considered to be a promising candidate, albeit its corrosion resistance still needs to be improved. The corrosion resistance of Zn–Fe plating is expected to increase by the addition of Mo as the third alloying element as it is more noble than Zn and Fe. In this study, Zn–Fe–Mo plating with a corrosion resistance nearly equivalent to that of the Zn–Ni plating was fabricated. Zn–Fe–Mo plating was electrically deposited from continuously-agitated plating baths prepared by mixing ZnSO4, FeSO4, Na2MoO4, Na3C6H5O7, and Na2SO4 using Fe or Ni plates as the substrate. The surface morphology, composition, crystal phase, and electronic state of Mo of the platings were investigated by scanning electron microscopy equipped with energy-dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The anti-corrosion performance was evaluated by Tafel extrapolation method. Formation of plating comprising a Mo containing alloy phase was found to be crucial for improving corrosion resistance. The Zn–Fe–Mo plating demonstrates promise for replacing anti-corrosion Zn–Ni platings

Electrodeposition of Copper/Carbonous Nanomaterial Composite Coatings for Heat-Dissipation Materials

Carbonous nanomaterials are promising additives for composite coatings for heat-dissipation materials because of their excellent thermal conductivity. Here, copper/carbonous nanomaterial composite coatings were prepared using nanodiamond (ND) as the carbonous nanomaterial. The copper/ND composite coatings were electrically deposited onto copper substrates from a continuously stirred copper sulfate coating bath containing NDs. NDs were dispersed by ultrasonic treatment, and the initial bath pH was adjusted by adding sodium hydroxide solution or sulfuric acid solution before electrodeposition. The effects of various coating conditions—the initial ND concentration, initial bath pH, stirring speed, electrical current density, and the amount of electricity—on the ND content of the coatings were investigated. Furthermore, the surface of the NDs was modified by hydrothermal treatment to improve ND incorporation. A higher initial ND concentration and a higher stirring speed increased the ND content of the coatings, whereas a higher initial bath pH and a greater amount of electricity decreased it. The electrical current density showed a minimum ND content at approximately 5 A/dm2. Hydrothermal treatment, which introduced carboxyl groups onto the ND surface, improved the ND content of the coatings. A copper/ND composite coating with a maximum of 3.85 wt % ND was obtained

Effect of the Addition of Molybdenum on the Structure and Corrosion Resistance of Zinc–Iron Plating

Zn–Ni plating is indispensable in various industries because of its high corrosion resistance. However, Ni has been reported to trigger allergies; thus, an alternative Ni-free plating is desired. Zn–Fe plating is considered to be a promising candidate, albeit its corrosion resistance still needs to be improved. The corrosion resistance of Zn–Fe plating is expected to increase by the addition of Mo as the third alloying element as it is more noble than Zn and Fe. In this study, Zn–Fe–Mo plating with a corrosion resistance nearly equivalent to that of the Zn–Ni plating was fabricated. Zn–Fe–Mo plating was electrically deposited from continuously-agitated plating baths prepared by mixing ZnSO4, FeSO4, Na2MoO4, Na3C6H5O7, and Na2SO4 using Fe or Ni plates as the substrate. The surface morphology, composition, crystal phase, and electronic state of Mo of the platings were investigated by scanning electron microscopy equipped with energy-dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The anti-corrosion performance was evaluated by Tafel extrapolation method. Formation of plating comprising a Mo containing alloy phase was found to be crucial for improving corrosion resistance. The Zn–Fe–Mo plating demonstrates promise for replacing anti-corrosion Zn–Ni platings

Surface-microporous graphene for CO2 adsorption

As an important greenhouse gas, CO2 attracts much attention due to its increasing emission. The adsorption and conversion of CO2 are effective ways to capture and utilize CO2, respectively. Herein, 3D graphene with surface-microporous structure, which was synthesized directly from CO2, was demonstrated as an efficient adsorbent for CO2 adsorption. The surface-microporous structure possesses advantages in the mass diffusion process and exposure of adsorption sites for CO2, achieving a high adsorption capacity of 2.28 mmol g−1 at 298 K and 1 bar. The adsorption capacity was further increased to 3.13 mmol g−1 by KOH activation. Such a great improvement can be attributed to the increased oxygen-functional groups

Aluminum Electrodeposition on the Surface of Boron Carbide Ceramics by Use EMIC–AlCl3 Ions Liquid

Coating technology is decisively important for metallization of ceramic materials and ceramic metal sealing technology. Previous studies have shown that the network-like structure after penetration of molten aluminum can significantly improve the strength of joint components. However, the direct aluminum coating method is limited by the shape of the substrate. To obtain a dense aluminum film on the surface of B4C, in this study, aluminum was deposited by pulse electroplating in EMIC–AlCl3 ionic liquid. The deposited metals were observed and analyzed by SEM–EDS and XRD. A Vickers hardness tester was adopted as an auxiliary equipment to clarify the film quality. The results show that frequency and duty cycle have significant effects on crystal orientation. The content of oxides in the contact gap reduces the bonding strength of the deposited metal, which provides experimental basis for metal electrodeposition on B4C