In this study, porous g-C3N4 based nanoarchitectures were obtained by a facile and effective in-situ synthesis method, that entailed the thermal treatment of different melamine (M) and urea (U) precursor mass ratios (in particular M/U = 50:50, 20:80), which were then compared with g-C3N4 obtained from pure M and U. The role of the melamine/urea mass ratio on morphology, structure, surface area, porosity, optical and vibrational properties of the g-C3N4 -based materials, was analysed in detail by means of many characterization techniques, including FESEM, AFM , XRD, HRTEM, Raman, FTIR, UV and PL spectroscopies, BET and TGA analyses. It will be shown that samples obtained from different M and U precursor mass ratios combine the advantage of high thermal stability and significant reaction yields, which are due to melamine action, and greatly improved surface area and short migration paths, which are due to urea effect, thus providing the suitable conditions for charge transfer within the interfaces. The results may shed light on effective improvements in the structure/properties of g-C3N4 based nanoarchitectures, aiming at peculiar functional materials.