Characterization of Anodized TiO₂ for Hydrogen Evolution in Enzymatic PEC System

In this study, an anodized TiO2 electrode (ATE) on a titanium foil was prepared and used as a photoanode in an enzymatic photoelectrochemical system to split water into oxygen and hydrogen. The effect of applied voltage when anodized, thickness of foil, electrolytes, annealing temperature, and species of cathode was investigated. The optimum conditions were obtained such as 0.25 mm foil thickness, 20V of applied voltage in 0.5 vol% of hydrofluoric acid, and 650 oC of annealing temperature. The samples with higher activities had similar X-ray diffraction (XRD) patterns, clearly indicating that the samples showing the highest evolution rate were composed of both anatase and rutile, while those showing a lower evolution rate were made of either anatase or rutile. Increasing the intensity of the irradiated light caused a remarkable enhancement in the rate of hydrogen production up to 153 μmol/(hr×cm2) under light intensity of 146 mW/cm2.