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.