Solar-driven photo-oxidation is a very attractive and efficient technique for chemical conversion of organic dyes in water into non-hazardous compounds, but it requires a catalyst in order to overcome the barrier of oxidation degradation. In this study we use a membrane photo-reactor (MPR) made of nanosheets of graphitic carbon nitride (g-C3N4), assembled by vacuum filtration. The membrane was characterized by X-Ray Diffraction (XRD), Nuclear Magnetic Resonance (NMR), electron microscopy and IR spectroscopy. Photo-degradation studies show that the membranes are very efficient in the degradation of Sudan orange G, rhodamine 110 and methylene blue. As the catalyst is a porous laminate, the reactant can flow through the pores of the membrane. Because the space between g-C3N4 nanosheets is comparable to the size of the dyes, the probability of the reactants to be close to the catalyst is enhanced, making the reaction very efficient.