The use of titanium dioxide nanotubes as photoanodes for chloride oxidation

In recent years, significant attention has been given to the development of photoelectrochemical materials capable of producing high current densities under illumination for a range of applications. Titanium dioxide nanotubes (TiNTs) have emerged as a favourable nanomaterial due to a reduced rate of recombination coupled with the ability to generate stable and high photocurrents. To date however, there have been no reports on the use of TiNTs for the photoelectrochemical production of chlorine, a powerful disinfectant, under UV light. The work reported here describes the construction of TiNTs for chlorine generation under low power UV-Light Emitting Diode (UV-LED) irradiation. Linear sweep voltammetry has shown TiNTs to be active for chlorine generation, achieving an average faradaic yield of ~60%, which was found to be significantly higher when compared to sol-gel electrodes (~40%). Furthermore, the impact of electrode conditioning was evaluated, demonstrating improved performance after removing surface contaminants.