6533b7d7fe1ef96bd1267951
RESEARCH PRODUCT
Photocatalytic degradation of organic compounds in aqueous systems by transition metal doped polycrystalline TiO2
Leonardo PalmisanoShigeru IkedaA. Di PaolaGiuseppe MarcìBunsho OhtaniElisa I. García-lópezsubject
chemistry.chemical_classificationAqueous solutionChemistryFormic acidCarboxylic acidInorganic chemistryGeneral ChemistryCatalysisCatalysischemistry.chemical_compoundTransition metalPoint of zero chargePhotodegradationBenzoic aciddescription
Abstract Some probe catalytic photooxidation reactions with aliphatic and aromatic organic compounds having different acid strengths, i.e. methanoic acid, ethanoic acid, benzoic acid and 4-nitrophenol, were carried out in aqueous systems by using polycrystalline TiO2 powders doped with various transition metal ions (Co, Cr, Cu, Fe, Mo, V and W). The Co-doped powder showed to be more photoactive than the bare TiO2 for methanoic acid degradation while the behaviour of TiO2/Cu and TiO2/Fe was similar to that of the support. TiO2/W was the most efficient sample for the photodegradation of benzoic acid and 4-nitrophenol, TiO2 the most active powder for ethanoic acid. A tentative explanation is provided by taking into account: (i) the dissociation constants (Ka) of the different acids used as substrates; (ii) their aliphatic or aromatic nature; (iii) the points of zero charge (PZC) of the photocatalysts; (iv) their relative rate constants for photoelectron–hole recombination (kr) determined by femtosecond pump-probe diffuse reflectance spectroscopy.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2002-07-01 | Catalysis Today |