Development and Characterization of Ni-Cobalt Oxide Coatings for Functional Applications

Nanoparticles of Cobalt oxide (Co 3 O 4 ) was prepared by green chemistry method using plant resources. Leaf and stem extract of Trionella-Foenum Graecum (Fenugreek) was used for the synthesis of Co 3 O 4 nanoparticles. The obtained nanoCo 3 O 4 particles were used in elelctroplating bath solution to get Ni-CoO nanocoatings on aluminium alloy substrates. Characterization of nanoparticles and the composite coatings were carried out through EDAX, SEM, XRD and FTIR studies. EDAX confirms the presence of cobalt and oxygen in the nanoparticles as well as in the coatings. SEM studies showed the spherical morphology of the nanoparticles and the coatings exhibited rod like structure. XRD studies confirms the nanosize of particles and maximum peak was obtained at (311) confirming the presence of nanocobalt oxide. The developed coatings showed higher solar absorptance and low infrared emittance, indicating better solar selectivity of the coatings. The coatings also exhibited good corrosion resistance.