A study on the effect of low energy ion beam irradiation on Au/TiO2 system for its application in photoelectrochemical splitting of water

Abstract Nanostructured TiO 2 thin films were deposited on indium tin oxide (ITO) substrate via sol–gel technique and were modified by plasmonic Au layer. The plasmonic Au modified TiO 2 (Au/TiO 2 ) thin films were then irradiated with 500 keV Ar 2+ ion beam at different ion fluences viz. 1 × 10 16 , 3 × 10 16 and 1 × 10 17 to study the effect of nuclear energy deposition on the morphology, crystallinity, band gap, surface plasmon resonance (SPR) peak exhibited by Au particles and photoelectrochemical properties of the system. Prepared thin films were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), Rutherford backscattering spectrometry (RBS) measurements and UV–visible spectroscopy. The photoelectrochemical measurements revealed that both Au/TiO 2 and Au/TiO 2 thin film irradiated at 1 × 10 16 fluence exhibits enhanced photoelectrochemical response in comparison to pristine TiO 2 . The film irradiated at 1 × 10 16 fluence offered maximum applied bias photon-to-current efficiency (ABPE) and shows 6 times increment in photocurrent density which was attributed to more negative flat band potential, maximum decrease in band gap, high open circuit voltage ( V oc ) and reduced charge transfer resistance.