Over the past decade, nanostructured TiO2 has been widely
investigated for enormous potential environmental applications
especially for the usage as photocatalyst to purify wastewater containing
refractory and toxic organic pollutants due to its excellent
chemical and physical properties [1–4]. However, the high recombination
rate of photo-generated electron/hole pairs in TiO2 results
in the low quantum yield, and thus the low photocatalytic efficiency
[5]. So the photoelectrocatalytic oxidation was introduced, which
enhances the separation of photo-generated electron/hole pairs by
applying a biased potential across the photoelectrode