In this work, a straightforward solvothermal approach to growing titanium dioxide (TiO2) structures into porous silicon substrates was developed. It was possible to modulate the morphology and optical characteristics of TiO2 by varying the concentration of the precursor and the kind of solvent. It was determined that these parameters strongly influence the morphology, photoluminescent response, bandgap, and structural characteristics of TiO2. The morphology of the TiO2 particles deposited on the walls of porous Si can be modulated from elongated particles to nanoflakes by increasing the precursor concentration. On the other hand, their morphology is flake-like, semi-spherical, and sea urchin-like, for methanol, ethylene glycol, and acetone, respectively. The particle size also varies with the precursor concentration; the size is smaller for lower concentrations, producing that the bandgap and emission energy increase. The variety of TiO2 structures presented in this work, with different properties, can find potential applications in photocatalysis, solar cells, and sensing devices.