Heterostructured Er3+ doped BiVO4 with exceptional photocatalytic performance by cooperative electronic and luminescence sensitization mechanism

Er-BiVO4 has been synthesized by means of mw-assisted hydrothermal method having good photoactivity under sun-like excitation. It is stated that the precursor addition sequence plays a critical role which determine the further structural feature of BiVO4. From the structural and morphological characterization, it can be demonstrated that the presence of Er3+ would induce the stabilization of the tetragonal phase probably due to the formation of tetragonal-ErVO4 seeds previous to BiVO4 formation. The best photocatalytic performance is attained for the sample with 0.75 at% Er3+ content. At this dopant loading a mixture of tetragonal and monoclinic phase (70% tetragonal) is obtained. The dramatic increase in the photocatalytic activity for 0.75 at% Er-BiVO4 is related to the occurrence of such heterostructure. For this system, the MB degradation rate constant appears drastically higher as bare m-BiVO4. Furthermore, activities of photocatalysts for visible-light-driven O-2 evolution have been evaluated, demonstrating that the photocatalytic activity of this Er-doped system (O-2 evolution rate, 1014 mu mol g(-1) h(-1)) is 20 times as that of undoped m-BiVO4 (O-2 evolution rate, 54 mu mol g(-1) h(-1)). From the obtained results, the cooperative conjunction of electronic and luminescence mechanism involved in the reaction is proposed to be the origin of the enhanced photocatalytic efficiencies of such systems. (C) 2014 Elsevier B.V. All rights reserved.