Ceria Particles as Efficient Dopant in the Electrodeposition of Zn-Co-CeO2 Composite Coatings with Enhanced Corrosion Resistance: The Effect of Current Density and Particle Concentration

Abstract

Novel Zn-Co-CeO2 protective composite coatings were deposited successfully from chloride plating solutions. Two different types of ceria sources were used and compared: commercial ceria powder and home-made ceria sol. Electrodeposition was performed by a direct current in the range of 1–8 A dm−2. Two different agitation modes were used and compared, magnetic stirring and ultrasound-assisted stirring (US). The influence of magnetic stirring on the stability of the related plating baths was evaluated via a dynamic scattering method. The results pointed to better stability of the prepared ceria sol. The morphology of the composite coatings was examined by scanning electron microscopy (SEM), and particle content was determined by energy-dispersive X-ray spectroscopy (EDS). The results showed that the increase in the deposition current density was not beneficial to the coating morphology and particle content. The corrosion behavior of the Zn-Co-CeO2 composite coatings was analyzed and compared by electrochemical impedance spectroscopy and polarization resistance. The ultrasound-assisted electrodeposition at small current densities was favorable for obtaining composite coatings with enhanced corrosion stability. The protection was more effective when US was applied and, additionally, upon utilization of ceria sol as a particle source, which was revealed by higher polarization resistance and greater low-frequency impedance modulus values for sol-derived composite coatings deposited under ultrasound.

Preclinical EIS Study of the Inflammatory Response Evolution of Pure Titanium Implant in Hank’s Biological Solution

“…Similar results were observed by other authors [ 28 ] who studied the reactions of the inflammatory compound H 2 O 2 in PBS solution with the titanium alloy Ti6Al4V. They observed the increase in the corrosion of titanium in correlation with the increase in the concentration of H 2 O 2 (from 0.8 mM to 330 mM), suggesting the formation of a Ti-H 2 O 2 complex that further led to the formation of a hydrated titanium compound: Ti(OOH) n [ 28 , 34 ].…”

“…The impedance modulus at low frequency can be correlated with the processes that take place at the interface of titanium with the solution (electrolyte), i.e., where the corrosion phenomena start to occur [ 26 , 34 ]; therefore, it is an effective tool for the elucidation of the studied electrode/electrolyte systems.…”

“…concentration of H2O2 (from 0.8 mM to 330 mM), suggesting the formation of a Ti-H2O2 complex that further led to the formation of a hydrated titanium compound: Ti(OOH)n [28,34].…”

Susceptibility of 316L Stainless Steel Structures to Corrosion Degradation in Salivary Solutions in the Presence of Lactic Acid

“…The most suggestive comparative evaluation of the susceptibility of 316L stainless steel to degradation due to the corrosion process is given by the values of the impedance modulus obtained at the low frequency of 0.01 Hz, knowing that, at this low frequency, the corrosion processes that take place on the metal surfaces in corrosive environments can be evaluated [35][36][37]. For the studied working solutions, the values of the impedance modulus of the 316L steel are presented in Figure 9a after one hour of immersion and in Figure 9b after 59 h of immersion.…”

Corrosion Behavior in Saline Solution of Electrodeposited Nanocomposite Zn-CeO2 Coatings Deposited onto Low Alloyed Steel

“…The particle incorporation results in a grain refinement with the assumption that they act as heterogeneous sites for zinc nucleation [12]. Kumar et al observed that the incorporation of WO 3 nanoparticles leads to more uniform, compact and smooth deposit and a slight refinement was observed when the nanoparticle concentration in the bath is increased [25][26][27][28][29][30][31][32][33][34][35][36]. Anwar et al suggest that the adsorption of TiO 2 nanoparticles on the surface of the growing Zn-Ni matrix inhibit the deposition process, leading to a refinement of the microstructure [26].…”