Excellent visible-light photocatalytic activity of p-type Ag2O coated n-type Fe2O3 microspheres

Ag2O/Fe2O3 p-n heterojunctions composed of flower-like Fe(2)o(3) and Ag2O nanoparticles have been prepared via a solvothermal precipitation-deposition method. They display higher photocatalytic activities than pure Fe2O3 for the degradation of RhB under visible-light irradiation. Among them, the Ag2O/Fe2O3 heterojunction with the Ag/Fe molar ratio of 0.2/1 (0.2Ag-Fe) exhibits the highest activity and good stability. It was even more active than the mechanical mixture (22.5 wt% Ag2O +77.5 wt% Fe2O3), The superior photocatalytic activity of Ag2O/Fe2O3 heterojunction can be ascribed to p-n heterojunction between Ag2O and Fe2O3, facilitating the efficient separation of photogenerated charge carriers. The photogenerated holes and superoxide radical anions mainly account for the RhB degradation. (C) 2016 Elsevier B.V. All rights reserved.