Photo-catalytic studies of Mn and Fe tetraphenyl porphyrins in the degradation of Amido Black 10B dye with solar light

Abstract

The free base tetraphenyl porphyrin (TPP) and its metalloporphyrins such as tetraphenylporphinatomanganese chloride (MnTPPCl), μ-Oxo-bis [tetraphenylporphinatomanganese [O-(MnTPP)2], tetraphenylporphinatoiron chloride (FeTPPCl) and μ-Oxo-bis [tetraphenylporphinatoiron] [O-(FeTPP)2] were synthesized in the laboratory and characterized by UV–visible, IR, Proton NMR and Fluorescence spectroscopy. Diffused reflectance spectroscopy revealed that all these compounds are low band gap semiconducting type materials. The photo-degradations of Amido Black 10B were performed to explore the photo-catalytic activity of these porphyrins using solar radiation at different pH conditions. In the present experiment attempts were made to use metal porphyrins without any supporting material, indirectly also to prove the photodynamic capabilities of these materials. It was revealed that pH plays an important role in the degradation of dye. The HPLC analysis of the product showed three components with same retention time irrespective of pH and ion chromatography indicated the mineralization of dye during degradation process. The results have shown the mineralization of the dye by redox reactions that are taking place at the respective groups present in the dye molecule. This eco-friendly remediation appears as a promising technique for degradation or mineralization of organic matter from contaminated water resources.