Degradation of mixed dyes in aqueous wastewater using a novel visible light driven LiMg0.5Mn0.5O2 photocatalyst

A simple and modified sal gel method was employed for the synthesis of LiMg0.5Mn0.5O2 and it was further investigated as the photocatalyst under visible light irradiation. LiMg0.5Mn0.5O2 was characterized using various analytical techniques in order to understand its phase confirmation, optical properties, morphology and chemical composition. The color of the LiMg0.5Mn0.5O2 was dark brown as it could be expected from its absorption spectrum. The bandgap energy of LiMg0.5Mn0.5O2 was estimated as 1.42 eV and therefore it would respond under visible light. The photocatalytic activity of LiMg0.5Mn0.5O2 was assessed based on the mixed aqueous solutions containing methylene blue (MB) and methyl orange (MO) under visible light. The photocatalyst showed preferential decomposition of MO in comparison to MB in the mixed dye solution. Different scavenger tests were carried out to detect the reactive species, responsible for the degradation of dyes and the possible photocatalytic degradation mechanism was also discussed.