Interaction of Iron Tetrasulfophthalocyanine with TiO2 Nanoparticles by XPS

Mesoporous iron tetrasulfophthalocyanine/TiO2 nanoparticles were prepared by a one-pot hydrolytic process starting from modified titanium alkoxide. The material has been characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), x-ray diffraction powder (XDR), transmission electronic microscopy (TEM), nitrogen absorption-desorption isotherm (BET), diffuse reflectance UV-visible spectrocopy and x-ray photoelectron spectroscopy (XPS). It contains anatase as the main crystalline phase (85%) along with brookite. Average crystallites size gave around 10 and 12 nm, for anatase and brookite, respectively. Diffuse reflectance UV-visible spectroscopy confirmed the presence of intact iron tetrasulfophtahlocyanine (FePcS), predominantly in dimeric form. The chemical interaction of the FePcS with the TiO2 nanoparticles was studied by using FTIR and XPS techniques which indicated that FePcS is covalently bonded onto TiO2 nanoparticles, leading to a stable hybrid system. Careful attention to binding energies of O 1s and S 2p elements in the nanohybrid material and in FePcS complex helps to shed light on this point.