Photo-persistent effect-induced energy band bending at the TiO2/Ag nanoparticle surface plasmonic interface

Abstract

For the first time, we have demonstrated a coupling of the photo (UV)-persistent-effect-induced energy band bending with localized surface plasmonic resonance (LSPR)-induced charge separation at the TiO2/Ag nanoparticle (NP) interface using Kelvin Probe Force Microscopy. Illumination with green light leads to a decrease in the surface potential due to the LSPR-induced electron transfer from the Ag NP to the TiO2, followed by electron transfer from the TiO2 to the Ag NP. Subsequent illumination with green light leads to electron transfer from the Ag NP to the TiO2, charging the TiO2/Ag NP surface positively. Our findings can be applied to creating and optimizing LSPR-induced gas sensing devices, providing insight into the design of surface-gas molecule pairing by adjusting the energy band level through UV gating. © 2022