Carrier Transfer and Capture Kinetics of the TiO2/Ag2V4O11 Photocatalyst.

In this paper, TiO2/Ag2V4O11 nanoheterojunctions have been synthesized by hydrothermal methods, which show enhanced photocatalytic activity compared to TiO2 under visible light. Moreover, the TiO2/Ag2V4O11 nanoheterojunction with set molar ratio of 2:1, referred to as TA2, show the highest visible light photocatalytic activity, which could decompose about 100% RhB molecules within 80 min of irradiation with visible light. Specially, the time-resolved photoluminescence spectrum of TA2 demonstrates that the free exciton recombination occurs in approximately 1.7 ns, and the time scale for Shockley-Read-Hall recombination of photogenerated electrons and holes is prolonged to 6.84 ns. The prolonged timescale of TA2 compared to TiO2 and Ag2V4O11 can be attributed to the carrier separation between nanojunctions and the carrier capture by interfacial defects. Furthermore, the enhanced photocatalytic activity of TiO2/Ag2V4O11 nanoheterojunctions also benefits from the synergistic effect of the broadened absorption region, higher photocarrier generation, longer carrier lifetime, and quicker collection dynamics.

Flake-like InVO4 modified TiO2 nanofibers with longer carrier lifetimes for visible-light photocatalysts.

Highly efficient solar light absorption capabilities and quantum yields in photocatalysts are key to their application in photocatalytic fields. Towards this end, TiO2/InVO4 nanofibers (NFs) have been designed and fabricated successfully by a one-pot electrospinning process. The resulting TiO2/InVO4 NFs display excellent visible-light photocatalytic activity, owing to their prominent visible-light absorption and electron-hole separation properties. Time-resolved transient PL spectroscopy demonstrated that the TiO2/InVO4 NFs display longer emission decay times (22.0 ns) compared with TiO2 NFs (15.5 ns), implying that the heterojunction can remarkably suppress the electron-hole recombination and promote the carrier transfer efficiency. With tailored heterostructure features, TiO2/InVO4 NFs exhibit superior visible-light photodegradation activity, and after 80 min of visible-light irradiation, almost 95% of RhB molecules can be decomposed by TiO2/InVO4 NFs, while only 18% of RhB molecules can be decomposed by pure TiO2 NFs.