The great versatility of semiconductor materials and the possibility of generation of electrons, holes, hydroxyl radicals, and/or superoxide radicals have increased the applicability of photoelectrocatalysis dramatically in the contemporary world. Photoelectrocatalysis takes advantage of the heterogeneous photocatalytic process by applying a biased potential on a photoelectrode in which the catalyst is supported. This configuration allows more effectiveness of the separation of photogenerated charges due to light irradiation with energy being higher compared to that of the band gap energy of the semiconductor, which thereby leads to an increase in the lifetime of the electron-hole pairs. This work presents a compiled and critical review of photoelectrocatalysis, trends and future prospects of the technique applied in environmental protection studies, hydrogen generation, and water disinfection. Special attention will be focused on the applications of TiO 2 and the production of nanometric morphologies with a great improvement in the photocatalyst properties useful for the degradation of organic pollutants, the reduction of inorganic contaminants, the conversion of CO 2 , microorganism inactivation, and water splitting for hydrogen generation.

Photoelectrocatalytic oxidation of 0.1mM of Bisphenol A (BPA) leads to 100% of degradation monitored by liquid chromatography with diode array optical detection (limit 1microgL(-1)) and 100% TOC removal. Optimum performance was obtained using TiO(2) nanotubular array (NTA) electrodes, grown by anodization of Ti foil in 0.25wt.% NH(4)F and a mixture of glycerol and water (ratio 90:10vol.%) using an applied voltage of 20V for 50h. The effects of supporting electrolyte, pH, applied bias potential and BPA concentration were evaluated as to their effect on the BPA degradation kinetics and the best condition was found to be 0.1M Na(2)SO(4) at pH 6 as supporting electrolyte and applied bias potential of +1.5V vs. Ag/AgCl under UV irradiation. Our findings indicate that TiO(2) NTAs prepared by anodization are versatile and efficient photocatalysts for the degradation of endocrine disruptors.

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