Erbium doped TiO2 interconnected mesoporous spheres as an efficient visible light catalyst for photocatalytic applications

Semiconductor metal oxides have gained enormous attention due to decomposition of organic pollutant from waste water. Among them TiO₂ is one of the most promising photocatalyst with a wide range of applications. It has wide band gap of 3.2 eV which limits its activity to the UV range. Therefore TiO₂ (as host matrix) can be doped with a luminescent material to form a phosphorous material which can convert incoming sunlight radiation. One of the interesting luminescent material is Er³⁺ as it can convert near infrared or visible light to visible and UV light, thus improving the photocatalytic activity of TiO₂. In this work, we have synthesized Erbium (Er) doped mesoporous TiO₂ spheres by solvothermal method. Effects of Er concentration on the formation and their photocatalytic activity have been investigated. Structural and compositional analysis confirms the presence of Er in the composition. Morphological analysis confirms the formation of mesoporous structure with erbium incorporation on the surface of mesoporous spheres. Elemental mapping confirms the uniform distribution of erbium on the surface of mesoporous structure. Photocatalytic activity of the samples was studied, the samples with 1 mM of Er showed the best photocatalytic activity over the pure TiO₂.