Visible-light activation of low-cost rutile TiO2 photoanodes for photoelectrochemical water splitting

Structure and photoelectrochemical properties of rutile-based TiO2 films formed by high-temperature oxidation of titanium metal are described. It is shown that a chemical etching treatment leads to the activation of initially almost inert film allowing its operation as visible light responsive water photo-oxidation photoanode. Additional use of a polyoxometalate electrocatalyst in the supporting electrolyte results in a 0.9 mA cm-2 photocurrent under simulated 1 sun irradiation at 1.23 V vs. RHE.