Degradation of p-nitrophenol and bacteria with TiO2 xerogels sensitized in situ with tetra(4-carboxyphenyl)porphyrins

TiO2-based materials doped with porphyrins have been prepared using a sol–gel process. To stabilize the TiO2-dye interactions, free metal tetra(4-carboxyphenyl)porphyrin and nickel tetra(4-carboxyphenyl)porphyrin were introduced in situ into the TiO2 matrix during the sol–gel process rather than by grafting. Samples were thoroughly characterized by TEM, X-ray diffraction, FT-IR, DR-UV/vis and their texture has been examined by nitrogen adsorption–desorption at 77 K. The low thermal treatment allows obtaining anatase-TiO2 particles with high specific surface area without porphyrin degradation. A significant improvement of the photoactivity under visible light of porphyrin doped-TiO2 xerogels was observed for p-nitrophenol and for bacterial degradation.