Photocatalytic evaluation of Hemin (chloro(protoporhyinato)iron(III)) anchored ZnO hetero-aggregate system under UV/solar light irradiation: A surface modification method

This work describes the photocatalytic activity of Hemin surface modified ZnO. The materials obtained were characterized by powder X-ray diffraction (PXRD), ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The spectroscopic results strongly confirm the strong absorption in the visible region and chemisorption of Hemin molecule on ZnO surface through O=C-O-Zn bond. These bonds not only enhance the extent of adsorption, but it can also act as an electron transfer channels facilitating the smooth electron transfer process. Further the FTIR spectroscopic data confirms the monodentate binding mode of Hemin on ZnO surface. The photocatalytic activity of prepared photocatalysts was investigated by degradation of 4-nitrophenol (4-NP) as a model compound in an aqueous solution under both UV and solar light irradiation. The rate of photocatalytic reaction increases in the presence of appropriate amount of H2O2 under UV light and sacrificial electron donor (TEOA) under visible light. The development of the porphyrin based photocatalyst provides an alternative approach to show promising prospect for the waste water treatment in future industrial application.