Visible light photoelectrochemical response of copper deposited titanium dioxide nanotubes

Abstract

This paper presents a novel preparation of copper (Cu) deposited titanium dioxide (TiO 2 ) nanotubes in photoelectrochemical systems. The main target was improving TiO 2 applications in the areas of energy conversion under visible light. Herein, we investigated different amount of Cu deposited TiO 2 nanotubes using thermal evaporation technique. Based on the results, small amount of Cu (1.09 wt.%) showed the improvement in photoelectrochemical (PEC) response under visible light. Optimum amount of Cu deposited on TiO 2 nanotubes will inhibit recombination rate of photogenerated charge carriers and improve the charge separation and transfer under visible light illumination. However, the excess amount of Cu deposited on TiO 2 nanotubes will impede the photocurrent to flow and resulted in lower photoconversion efficiency. The reason may be attributed to the formation of composite structure on TiO 2 nanotubes that serve as defects in the Cu/TiO 2 interface by the lattice mismatch that will serve as recombination site for the charge carriers.