Interfacial electrochemistry of haematite (α-Fe2O3)

A study has been made of the electrostatics of the haematite (α-Fe2O3)/aqueous electrolyte solution interface. The haematite was a synthetic sample. Its surface properties have been characterized by several independent methods. There are positive indications of porosity. Surface-charge pH curves have been obtained by potentiometric titration. These measurements have been amplified by sol stability studies. Special attention has been paid to the influence of the nature of the electrolyte (KNO3, KCl, K2SO4, LiCl, CsCl, and the nitrates of Mg2+, Ca2+, Sr2+, and Ba2+). It appears that the electrical double layer on haematite has properties between those of silver iodide and mercury and those on silica.