An environment-friendly fabrication of nano-Co3O4 coating by aqueous electrophoretic deposition

摘要

Co3O4 coating is one of most studied transition metal oxide due to its wide application in many fields such as gas sensors, electrochromic thin films, supercapacitors, and solar selective absorber. Aqueous electrophoretic deposition (EPD), which is considered as a cost-effective and environment-friendly coating technology, was successfully employed in preparing nano-Co3O4 coating in this study. For the EPD process with the solid loading of 1 g L-1, 2.0 mM nitric acid was employed as suitable additive and 5 V was employed as deposition voltage. The prepared nano-Co3O4 coating exhibited good film characteristics, which was proved by scanning electron microscopy (SEM) technology. The result suggests that a rapid preparation of nano-Co3O4 coating in aqueous dispersion system can be easily accomplished. Moreover, the optimum concentrations of the added nitric acid would increase with the solid loading of Co3O4 nanoparticle, but the growth rate of the former was obviously lower than that of the latter.