Facet effect of alpha-Fe2O3 crystals on photocatalytic performance in the photo-Fenton reaction

Hematite (alpha-Fe2O3) has emerged as a promising photocatalyst for catalyzing the photo-Fenton reaction. In order to enhance the catalytic activity, tremendous effort has been made to engineer alpha-Fe2O3 catalysts with controllable facets. Different morphologies of alpha-Fe2O3 crystals, polyhedrons with exposed {101} and {001} facets, rods with predominant {001} facets, ellipses and cylinders, were selectively synthesized via a facile and environmentally-friendly hydrothermal method. The studies of their catalytic performance have indicated that polyhedrons exhibit much higher catalytic activity than the rods, ellipses and cylinders for the visible-light photocatalytic degradation of organic contaminants in the presence of hydrogen peroxide (H2O2). The possible reason may be attributed to the higher surface energy of {101} facets. Therefore the catalytic property of alpha-Fe2O3 nanomaterials is closely related to the surface atomic configurations that are determined by the morphology.