The field of semiconductor photoelectrochemistry and photocatalys is now more than 40 years old. Yet, the complexity of the interfacial charge transfer in nanostructured semiconductor systems continues to intrigue material chemists, spectroscopists and surface scientists. Although the primary process following the bandgap excitation of semiconductor nanoparticle is the electron-hole separation, the competing charge transfer processes at the semiconductor interface dictate the overall performance of semiconductor photocatalysts. Bipolar membranes provide interesting opportunities to build photocatalyst assemblies and separate oxidation and reduction reactions. Kinetic and mechanistic aspects of electron transfer processes within such membranes and their implications in water splitting reaction will be discussed.