Degradation of methylene blue using Ca-doped LaMnO3 as a photocatalyst under visible light irradiation

Abstract

Calcium doped lanthanum manganiteLa0.75Ca0.25MnO3 having Perovskite structure shows high degree of catalytic efficiency 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 showed the formation of single crystalline phase. SEM images shows that the micro sized LCMO sample has nanocrystalline structure with average diameter of 1–5 µm. The ICP-AES and EDX data confirmed formation of required stoichiometric La1-xCaxMnO3 Oxide. On account of reduction of band gap energy by calcium doping, the Photocatalytic performance of the perovskites for photodegradation of Methylene Blue (MB) dye as an Organic water pollutant, was evaluated over visible light irradiation at constant dose for several hours, with a pH at 4,. The result showed the photocatalytic efficiency La0.75Ca0.25MnO3 nanocomposite was 68.52% of the initial dye concentration within 100 min illumination time. The linear increase of photodegradation rate was found in our sample as a function of time of irradiation. These findings shows convincingly that La1-xCaxMnO3 photocatalyst possess great promise for visible light driven photodegadation of MB dye. The reproducibility of the sample for degradation was studied.