Photocatalytic Degradation of Acid Chrome Blue K with Porphyrin-Sensitized TiO₂ under Visible Light

Abstract

We have investigated an application of TiO2 photocatalyst sensitized with meso-tetra (4-carboxyphenyl) porphyrin (H2TPPC) or meso-tetra (4-nitrophenyl) porphyrin (TNO2PP) to degrade acid chrome blue K (ACBK) under visible light irradiation. By injecting electrons from the photoexcited sensitizer to the conduction band, the sensitized TiO2 degraded acid chrome blue K under incandescent lamp irradiation. The results indicated that H2TPPC−TiO2 had remarkable effects on the photodegradation of ACBK under natural sunlight (NSL) irradiation. The initial concentration of ACBK of 10 mg/L gave the decolorization rate of ACBK under incandescent lamp irradiation up to 94% in 15 min. This confirms that the H2TPPC−TiO2 composite could fully decompose ACBK under artificial light and that this process was accelerated under NSL. All facts suggest that H2TPPC−TiO2 in the heterogeneous photocatalysis phase has a potential application in wastewater treatment by using NSL.