WO3,1 hematite (α-Fe2O3)2 and WO3-BiVO4 are wide band gap semiconductors that can be obtained under nanocrystalline form and serve as the photo-anodic compartment (i.e. the oxygen evolving compartment) of a photoelectrochemical cell for solar fuel production. In this contribution some results about the charge transfer dynamics at the semiconductor/electrolyte interface gained by combining Transient Absorption Spectroscopy and Electrochemical Impedance Spectroscopy are reported. Viable approaches to improve the photoelectrochemical response of these materials are also discussed. Finally, we focus on the environmental applications of these materials, by considering the degradation of some Contaminants of Emerging Concern which are present in potable water and are impervious to conventional decontamination techniques.3