Composition design and anticorrosion performance optimization of zinc molybdate pigments

Exploring the design of zinc molybdate pigments to optimize their properties is an interesting work. Three types of zinc molybdate, amorphous ZnMoO4, Zn5Mo2O11·5H2O, and β-ZnMoO4, were synthesized by regulating the synthesis conditions. Experimental results revealed that the monoclinic β-ZnMoO4 possessing a distorted octahedral [ZnO6]/[MoO6] cluster structure exhibited the optimal anticorrosion and photocatalytic properties. Then, the synergistic anticorrosion mechanisms of β-ZnMoO4 were proposed: multilayer shielding layer protection and photoelectrons suppression effect of anodic reaction. Next, three surfactants, sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), and polyvinylpyrrolidone (PVP-K30), were employed to modulate the growth of β-ZnMoO4. Experimental data showed that the induced modulation of PVP-K30 could greatly increase the specific surface area and photoelectrons production efficiency of β-ZnMoO4. Besides, the charge transfer resistance of β-ZnMoO4-P (synthesized with PVP-K30) was 25.58 times higher than that of β-ZnMoO4-0 (synthesized without surfactant) after 72 h of immersion in 3.50 wt.% NaCl solution. Consequently, the design strategy of zinc molybdate pigments provides a reference for the improvement of performance of other inorganic anticorrosion pigments in industry.