304902-13-4Relevant academic research and scientific papers
Phororedox and photocatalytic processes on FE(III)-porphyrin surface modified nanocrystalline TiO2
Amadelli,Battioni,Molinari,Mansuy,Antolini,Maldotti
, p. 521 - 531 (2008/10/08)
Molecular modification of surfaces is a field of high interest in heterogeneous catalysis. Much work has been conducted on the modification of semiconductor surfaces for improving stability and charge separation. These studies have provided an impetus to investigations on using semiconductors as light-harvesting systems or as catalysts for pollution abatement. Surface derivatization of TiO2 nanoparticles with a Fe(III)-porphyrin was performed following a novel procedure whereby the complex contains the aminopropylsilane functional group instead of the surface. Characterization of the light-transparent dispersions by laser flash photolysis, UV-vis spectroscopy, and photo-electrochemical techniques showed that the nature of the solvent is an important parameter in determining the redox processes involving the grafted porphyrin. Marked effects on the stability of the Fe(II)-porphyrin formed upon capture of the photogenerated electrons were observed. The bonded porphyrin improved the yield and formation of the monooxygenation products with respect to total degradation to CO2 for both the examined substrates. An increase in the efficiency and selectivity with the composite photocatalytic system was claimed on this basis. In the case of cyclohexane, the iron-porphyrin complex changed the selectivity of the process, increasing the alcohol/ketone ratio.
