Controlled band energetics in Pb-Fe-Nb-O metal oxide composite system to fabricate efficient visible light photocatalyst

摘要

We report here an efficient Pb-Fe-Nb-O based composite oxide photocatalyst prepared by simple solid-state reaction method. The low band gap semiconductors of Pb2FeNbO6, FeNbO4, and composite (Pb2FeNbO6) : (FeNbO4) system were synthesized under various thermal conditions, and further systematically investigated for their physico-chemical properties. The composite of Pb-Fe-Nb-O oxide formed at 1100 °C was found to be doubly efficient photocatalyst than TiO_(2-x)N_x for the decolorization of methylene blue under solar radiation. This photocatalytic activity can be attributed to the role of Fe-d, Nb-d and Pb-f states in the band gap of (Pb2FeNbO6) : (FeNbO4) system. The smaller band gap of this material additionally contributes to the improved visible light photocatalytic activity over UV-active TiO2.