pH-responsive, TiO2-attached porphyrin for singlet oxygen production in an aqueous solution.
ACS Appl Mater Interfaces
; 1(8): 1778-84, 2009 Aug.
Article
em En
| MEDLINE
| ID: mdl-20209036
ABSTRACT
A pH-responsive, TiO2-attached sensitizer was prepared based on the adsorption of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) onto TiO2 nanoparticles. This colloidally dispersed TiO2-attached TCPP behaves as a single-phase colloidal sensitizer at pH 1.0-3.3 with quantum yields of singlet oxygen production (Phi(Delta)) between 0.20 and 0.25, as a heterogeneous particle sensitizer at pH 3.5-6.0 with Phi(Delta) between 0.25 and 0.50, and as homogeneous free TCPP molecules in alkaline solutions with Phi(Delta) = 0.53. The changes in Phi(Delta) are fully consistent with pH-dependent adsorption of TCPP onto the TiO2 surface. Recovery yields of 99.8% for TCPP and 98.8% for TiO2 were obtained from 1.4 mM TiO2-attached TCPP. We attribute its photosensitization ability to retaining TCPP solubility on the TiO2 surface and, hence, activity. This novel system shows a potential to bridge the gap between easily recoverable and highly efficient sensitizers.
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01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxigênio
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Porfirinas
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Titânio
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Água
Idioma:
En
Revista:
ACS Appl Mater Interfaces
Ano de publicação:
2009
Tipo de documento:
Article