Mixtures of TiO2 and carbon powders are tested as photoanodes in mini-photoelectrochemical cells based on Nafion electrolyte-impregnated microporous membranes. The composite TiO2+C working electrode is formed onto one face of the membrane (where a Ag/AgCl reference electrode is also adhered), whereas a stainless steel mesh counter electrode is attached to its opposite face. Photovoltammetry and constant potential photoamperometry carried out under UV-A illumination in the presence of water and methanol vapors result in well-defined photoelectrochemistry, characteristic of water and methanol photo-oxidation, and point to the possibility of scaling up similar devices to be used in electrically enhanced photocatalytic air treatment.