Structure and photocatalytic properties of Nb-doped Bi12TiO20 prepared by the oxidant peroxide method (OPM)

Abstract

Pure (Bi12TiO20) and niobium-doped (Bi12Ti1-xNbxO20, with "x'' up to 0.15) bismuth titanates were prepared by the oxidant peroxide method (OPM) and used to photodegradate rhodamine b (RhB) under UV and visible radiation. Rietveld refinements showed samples consisting mainly of sillenite structure with small amounts of a perovskite secondary phase in the Nb-doped materials. These bismuth-based catalysts exhibited superior performance than the commercial TiO2, with band gaps ranging from 2.53 of pure Bi12TiO20 to 2.73 eV depending on the amount of niobium added, which seems to be responsible for the improved photoactivity of the doped catalysts under UV radiation.