Synthesis, characterization and inhibition properties of ZnAlCe layered double hydroxide intercalated with 1-hydroxyethylidene-1,1-diphosphonic acid.

ZnAlCe layered double hydroxides intercalated with 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) were synthesized by the co-precipitation method. The surface morphology and structure of ZnAlCe-HEDP LDHs were observed and determined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. The inhibition behavior and mechanism of ZnAlCe-HEDP LDHs for Q235 steel in 3.5% NaCl solution was measured by weight loss, inductively coupled plasma mass spectrometer (ICP-MS), polarization curves, electrochemical impedance spectroscopy (EIS), energy dispersion spectrum (EDS) and X-ray photoelectron spectroscopy (XPS). The results show that the HEDP anion is successfully intercalated into ZnAlCe LDHs interlayer and the synthetic ZnAlCe-HEDP LDHs has a lamellar morphology with well-defined crystalline structure and a basal plane spacing 1.056nm. Compared with ZnAl-NO 3 LDHs and ZnAl-HEDP LDHs, ZnAlCe-HEDP LDHs has a better inhibition effect on Q235 steel in 3.5% NaCl solution. The higher inhibition effect of ZnAlCe-HEDP LDHs is related the reduction of chloride ions in solution by ion exchange effect between HEDP ions and chloride ions, and the formation of inhibition film on steel surface by the ferrous-HEDP chelates and zinc, aluminum and cerium hydroxides. [ABSTRACT FROM AUTHOR]