Enhanced photochemical properties of electron rich W-doped PbBi2Nb2O9 layered perovskite material under visible-light irradiation

Abstract

The substitution effect of W6+ at Nb5+ site in PbBi2Nb2O9, a layered Aurivillius-phase perovskite system, has been studied and further optimized to fabricate an efficient photocatalyst. The material doped with electron donor (W+6), PbBi2Nb2-xWxO9 with an optimum composition of x = 0.15 exhibited a red shifted (0.14 eV) band gap, generated two times higher photocurrent, and showed analogous higher quantum yield for photodecomposition of H2O/CH3OH solution than undoped material under visible light ((lambda >= 420 nm). In contrast, the material doped with hole donor (Ti+4) revealed deteriorated photochemical properties. The higher electron density by n-type doping seems to be responsible for the more efficient charge separation in PbBi2Nb2-xWxO9 (0<x<0.5). (C) 2007 Elsevier B.V. All rights reserved.