Unusual structural transformation and photocatalytic activity of Mn doped TiO2 nanoparticles under sunlight

Abstract

Here, Mn doped TiO2 nanoparticles are synthesised through sol-gel technique. After doping 1 and 2 at% Mn, the mixed phase of anatase and rutile is observed, whereas 3 at% Mn doped TiO2, shows pure anatase phase. Particle size of ∼12–15 nm is estimated from TEM showing single crystalline nature evidenced from SAED patterns. Such fine particles are primarily contributes to observed unusual transformation. As a consequence, oxygen vacancies and multiple oxidation states of Mn and Ti are detected through XPS. For the first time, Mn doped TiO2 show 80–100% photocatalytic degradation of dyes, such as MB, RhB and CR, under sunlight in 1 h, which might be regarded as a practical method for the treatment of waste water. The multiple oxidation states of Ti and Mn accompanied with oxygen vacancies reveal ferromagnetism and high degradation rate of organic dyes.