Quantum mechanical investigation of optoelectronic properties of gold nanoparticle attached titanium dioxide nanorods for device applications

This article reports gold nanoparticle (Au-NP) induced absorption enhancement in hydrothermally synthesized titanium dioxide nanorods (TiO2-NRs) with a possibility of the deposition of hybrid nanostructures on the transparent substrates. The localized surface plasmon resonance (LSPR) and hot electron transfer behaviour of Au-NPs attached to the TiO2-NRs has been correlated to their photocatalytic response. The photocurrent enhancement observed in amperometric studies has been explained on the basis of excess electron density in the conduction band of TiO2 due to hot electron transfer from the attached Au-NPs (size in the range of 3 to 44 nm). The quantum mechanical calculation of the electron transmission probability from the resonant Au-NP to the conduction band of TiO2-NR has been presented with respect to the wavelength of the incident spectrum. Further, the role of Au-NP size dependent electron work function has been correlated to the electron transmission probability. This study provides a quantum mechanical explanation to the better response of Au-NPs/TiO2-NRs system for photo-catalytic device applications.