Visible-light-induced photodissolution of α-Fe2O3 powder in the presence of chloride anions

Abstract

Haematite iron oxide (α-Fe₂O₃), an n-type semiconductor, has been shown to corrode in the presence of chloride anion in aqueous acidic media when in powder suspension. The rate of corrosion was enhanced by a factor of ten upon band-gap excitation using visible light. Surface adsorption and ease of complex formation with solution species are shown to be a major factor in the dissolution process. A mechanism for dissolution is proposed and implications for iron oxide powder photocatalysis are assessed.