Effect of calcination temperature on structural properties and photoCatalytic activity of Mn-C-codoped TiO2

Abstract

Mn-C-codoped TiO2 catalysts were synthesized by modified sol-gel method based on the self-assembly technique using polyoxyethylenesorbitan monooleate (Tween 80) as template and carbon precursor and the effect of calcination temperature on their structural properties and photoCatalytic activity were investigated. The XRD results showed undoped and Mn-C-codoped TiO2 calcined at 400 °C only include anatase phase and the rutile phase appears when the calcination temperature reached to 600 °C. UV-vis absorption spectroscopy demonstrates that the absorption spectra are strongly modified by the calcination temperature. Moreover, the Mn-C-TiO2 calcined at 400 °C showed the lowest PL intensity due to a decrease in the recombination rate of photogenerated electrons and holes under light irradiation. The photoCatlytic activity of Mn-C-codoped TiO2 were evaluated by the degradation of methyl orange (MO) under the simulate daylight irradiation and all the prepared Mn-C-codoped TiO2 samples exhibited high photoCatalytic activities for photoCatalytic decolorization of methyl orange aqueous solution. At 400 °C, the Mn-C-codoped TiO2 samples showed the highest photoCatalytic activity due to synergetic effects of good crystallize ation, appropriate phase composition and slower recombination rate of photogenerated charge carriers, which further confirms the calcination temperature could affect the properties of Mn-C-codoped TiO2 significantly.