Separating type I heterojunction of NaBi(MoO4)2/Bi2MoO6 by TiO2 nanofibers for enhanced visible-photocatalysis

Among tremendous efforts for enhanced photocatalysis, construction of heterojunction has been deemed as an effective means. In comparison with type II heterojunction, type I heterojunction receives less attention due to accumulation and increased recombination of charge carriers in one side of heterojunction. Herein, we take NaBi(MoO 4 ) 2 /Bi 2 MoO 6 as an example of type I heterojunction and explore means to improve the photocatalytic performance of NaBi(MoO 4 ) 2 /Bi 2 MoO 6 heterojunction. We employ TiO 2 electrospun nanofibers as substrates and separately grow NaBi(MoO 4 ) 2 and Bi 2 MoO 6 nanostructures on the skeleton of TiO 2 . The characterization results show that TiO 2 changes type I heterojunction into multiheterojunction integrating two type II heterojunctions. Photocatalytic tests demonstrate that as-constructed multi-heterojunction is of higher activity than that of single type I or II heterojunction, respectively, where photogenerated electrons are accumulated on the surface of TiO 2 and photogenerated holes are accumulated on NaBi(MoO 4 ) 2 and Bi 2 MoO 6 , respectively. This study highlights the potential application of TiO 2 electrospun nanofibers in the construction of multiheterojunction for enhanced visible light photocatalysis.