Photocatalytic Decomposition of Methylene Blue over Nanosized Ca2+ Doped LaMnO3 under Visible Light Irradiation

Abstract

The Photocatalytic performance of the Calcium doped lanthanum manganite nanocomposite for photodegradation of Methylene Blue(MB)  dye as an Organic water pollutant,was evaluated over visible light irradiation, at a pH of 4, at constant dose for several hours. The result showed La0.75Ca0.25MnO3 having Perovskite structure shows high degree of catalytic efficiency of 69% within 100 min illumination time, for the removal of Methylene Blue organic dye from its aqueous solution. The sample powder(LCMO) was prepared through sol-gel technique and was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Inductively coupled plasma- atomic emission spectroscopy (ICP-AES), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX) and UV-Vis spectroscopy (UV-Vis). The XRD data revealed the formation of single phase crystallinity.SEM images shows that the micro sized La0.75Ca0.25MnO3 powder has nanocrystalline structure with average diameter of 1-3 µm. The ICP-AES data confirmed formation of required stoichiometric La1-xCaxMnO3 Oxide. The rates of photodegradation linearly increase as a function of time of irradiation, which was confirmed from study of the optical properties of the resulting aqueous solutions. These findings shows convincingly that La0.75Ca0.25MnO3 photocatalyst possess great promise for visible light driven photodegadation of Methylene Blue dye.