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

TiO2 nanofibers helps disperse type I heterojunction to two type II heterojunctions. This leads to higher photocatalytic activity towards degradation of gaseous acetaldehyde. [Display omitted] •NaBi(MoO4)2 and Bi2MoO6 can be grown on TiO2 nanofibers.•Type I heterojunction can be separated to two type II heterojunctions by TiO2.•Two type II heterojunctions are more active than type I heterojunction. 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(MoO4)2/Bi2MoO6 as an example of type I heterojunction and explore means to improve the photocatalytic performance of NaBi(MoO4)2/Bi2MoO6 heterojunction. We employ TiO2 electrospun nanofibers as substrates and separately grow NaBi(MoO4)2 and Bi2MoO6 nanostructures on the skeleton of TiO2. The characterization results show that TiO2 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 TiO2 and photogenerated holes are accumulated on NaBi(MoO4)2 and Bi2MoO6, respectively. This study highlights the potential application of TiO2 electrospun nanofibers in the construction of multiheterojunction for enhanced visible light photocatalysis.