Effect of Calcium Doping on Photocatalytic Degradation Efficiency of LaMnO3 on Removal of Methylene Blue

This study addresses a significant environmental issue by exploring an efficient method for removing organic pollutants from wastewater, which is crucial for mitigating water pollution. The study's findings contribute to the development of advanced photocatalytic materials and techniques, offering potential solutions for wastewater treatment and environmental remediation. Calcium-doped lanthanum manganiteLa0.75Ca0.25MnO3 having a Perovskite structure shows a high degree of catalytic efficiency for the removal of organic pollutants (Methylene Blue dye) from its aqueous solution. Organic dyes in wastewater are effective environmental pollutants, the removal of which is a challenging issue. Photocatalytic degradation of such dyes on the surface of metal oxides has been intensively studied and it is found that semiconductor-mediated heterogeneous catalysts are promising candidates to degrade a wide range of organic pollutants. The sample powder(LCMO) has been prepared through the sol-gel technique and 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. The XRD data showed the formation of a single crystalline phase. SEM images showed that the micro-sized LCMO sample had a nanocrystalline structure with an average diameter of 1-5 µm. The ICP-AES and EDX data confirmed the formation of the required stoichiometric La1-xCaxMnO3 Oxide. Calcium doping resulted in the reduction of band gap energy(Eg) of the perovskite whose catalytic performance towards photodegradation of Methylene Blue(MB) dye(5 ppm) was evaluated over visible light irradiation at constant dose for several hours at pH value 4. The result showed the photocatalytic efficiency of La0.75Ca0.25MnO3 nanocomposite (0.07 g l-1) was 68.52 % of the initial dye concentration within 100 min illumination time. The linear increase in the rate of photodegradation was found in our sample as a function of irradiation time with a reaction rate of 1.582 x10-3 min-1. The activated electron in the conduction band also responds with an oxygen molecule that is adsorbed on the outer layer of the photocatalyst to form a superoxide radical. These findings showed convincingly that La1-xCaxMnO3 photocatalyst possessed great promise for visible-light-driven photodegradation of MB dye and signifies the effective material for environmental pollution remediation and water treatment technologies. The reproducibility of the sample for degradation was studied.