Shayan Sarraf, Seyedeh Marzieh Hosseini, Saeed Rastegari, Mansour Soltanieh,
Volume 23, Issue 3 (9-2026)
Abstract
In this study, Ni-Co-CeO2 nanocomposite coatings were deposited on copper substrates via a sol-enhanced electrodeposition method. Cerium oxide nanoparticles were synthesized using cerium chloride precursor and HMTA as a precipitating agent at 70 °C and subsequently added to a Watts bath containing nickel and cobalt ions. An investigation of the effect of deposition current density (10 to 30 mA.cm-2) revealed that increasing the deposition current density reduced the cerium oxide content in the coating from 12.2 to 7.1 wt%. SEM images confirmed a morphological transformation from an acicular structure to a fine-grained microstructure with surface heterogeneity in the presence of the nanoparticles. XRD results further demonstrated grain refinement induced by the CeO2 reinforcing phase. Electrochemical evaluations in 1 M KOH solution showed that the sample deposited at a current density of 20 mA.cm-2 exhibited the highest performance, with a discharge time of 92 seconds (a 77% improvement compared to the particle-free sample) and optimal charge transfer resistance. This enhanced performance is attributed to a favorable balance between the electrical conductivity of the metallic matrix and the catalytic activity of the cerium oxide nanoparticles. The findings of this investigation substantiate the efficacy of the sol-enhanced method in designing advanced electrodes for energy systems.
