Structures of β-FeOOH Particles Formed in the Presence of Ti(IV), Cr(III), and Cu(II) Ions

Abstract

β-FeOOH particles were prepared by aging aqueous FeCl3 solutions containing Ti(IV), Cr(III), and Cu(II) at room temperature for 360 days. The structures of the formed particles were investigated by various techniques including TEM, XRD, XAFS, and adsorption of N2 and H2O. Ti(IV) markedly impeded the crystallization and particle growth of β-FeOOH by coprecipitation with Fe(III) and disturbing the short-range structure of β-FeOOH particles. In the presence of a large amount of Ti(IV), it was pronounced that the hydrolysis of Ti(IV) impeded β-FeOOH formation by reducing the solution pH, whereas Cr(III) and Cu(II), which were hardly involved in the products, gave rise to no noticeable effects on the formation of β-FeOOH particles. The knowledge obtained in this study can be available for interpretation of the anti-corroding function of Ti alloyed with steels in a Cl−-containing environment.