Preparation of anticorrosive cobalt-doped ZnO nano pigments by a combustion method; A comparison study between microwave irradiation and a conventional heating source

摘要

In the present study, cobalt-doped ZnO nano pigments were synthesized by a solution gel combustion method using glycine fuel. A chamber furnace and microwave irradiation were used as heating sources. Products were characterized by X-ray diffraction, scanning-transmission electron microscopy and diffuse reflectance. The anticorrosive properties of the pigments obtained were investigated by electrochemical impedance spectroscopy. The results have shown that using glycine as the fuel pure ZnO phase was obtained directly by the two heating sources. Electron microscopy demonstrated quasi-spherical particles with a crystallite size of 49 nm for furnace-assisted and rod-like particles of 63 nm for the microwave-assisted procedure were obtained. The corrosion performance of the coating in 3% w/V NaCl solution was evaluated by electrochemical impedance spectroscopy (EIS) and polarization measurements. According to the measurements of EIS and electrochemical polarization, the coatings with a furnace-assisted pigment showed a higher corrosion resistance.