Influence of anions on the structure and morphology of steel rust particles prepared by aerial oxidation of acidic Fe(II) solutions

Abstract In order to simulate the atmospheric corrosion of steel, artificial steel rust particles were synthesized by aerial oxidation of aqueous solutions containing FeCl 2 , FeSO 4 and NaNO 3 , and the structure and morphology of the obtained particles were characterized by XRD and TEM. Needle-like SO 4 2− containing Schwertmannite (Fe 8 O 8 (OH) 6 (SO 4 )) particles were mainly formed in FeCl 2 –FeSO 4 , FeSO 4 –NaNO 3 , FeCl 2 –FeSO 4 –NaNO 3 systems, and the crystallization and particle growth of this material were not influenced by added Cl − and NO 3 − . The rod-shaped β-FeOOH particles were formed from in only FeCl 3 -NaNO 3 system, though no marked change in crystallite and particle sizes of the β-FeOOH was recognized by adding NO 3 − . Accordingly, it can be suggested that the corrosive SO X gas and air-borne chloride strongly affect the rust formation in atmospheric corrosion of the steels.