Enhancement of TiO₂-UV100 nanoparticles photocatalytic activity by Mg impregnation in the removal of a model organic pollutant

Abstract

In this study, Mg/TiO₂-UV100 nanoparticles were prepared by the impregnation method. The structural characteristics and properties of the obtained materials were investigated by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) and diffuse reflectance spectroscopy (DRS) techniques. XRD patterns of pure and impregnated TiO₂-UV100 nanoparticles revealed that all phases were anatase. The results of BET analysis for Mg/TiO₂-UV100 nanoparticles indicated a surface area of 171.8 m² g⁻¹. Maximum distribution pore size is about 2 nm, which is consistent with microporous structure. The particle size obtained from TEM was close to crystallite size calculated from XRD pattern. A comparison of DRS of the Mg/TiO₂-UV100 with bare TiO₂-UV100 showed a slight red shift. The photocatalytic degradation of C.I. Acid Red 27 (AR27) was investigated in the presence of TiO₂-UV100 and Mg/TiO₂-UV100 nanoparticles under different conditions. The photocatalytic activity of Mg-impregnated (0.8 mol%) TiO₂-UV100 in the removal of AR27 was higher than that of bare TiO₂-UV100 nanoparticles. The photocatalytic activity of Mg-impregnated (0.8 mol%) TiO₂-UV100 was very sensitive to dopant content, initial concentration of the AR27, catalyst dosage, light intensity, and pH. The results indicated that the use of photocatalytic method in the presence of Mg-impregnated TiO₂-UV100 nanoparticles was a good choice for eliminating organic pollutants from aqueous media.

Keywords:

• Heterogeneous photocatalysis
• Impregnation
• TiO₂-UV100 nanoparticles
• Magnesium
• C.I. Acid Red 27

Acknowledgments

The authors would like to thank the financial support of the Islamic Azad University, Tabriz Branch, and the Iranian Nanotechnology Initiative Council.