SYNTHESIS AND CHARACTERIZATION OF PURE AND Sm-, Zr-DOPED TiO2 NANOFIBERS AND ITS PHOTOCATALYTIC ACTIVITY

Pure, samarium (Sm3+) and zirconium (Zr4+) doped titanium dioxide (TiO2) nanofibers were synthesized using the electrospinning method followed by calcination at 500 °C for 1 h. The structure, morphology and optical properties of the obtained nanofibers were investigated as a function of different Sm3+ and Zr4+ contents (0.5–5 mol%). XRD and FTIR analysis showed that addition of Sm or Zr suppressed the transformation of anatase to rutile. After calcination all fibers were smooth, fragile and randomly oriented. HRTEM analysis revealed that doping with Sm didn’t affect the TiO2 crystal lattice whilst Zr4+ ions replaced the substitutional sites in the anatase crystalline lattice. The effects of Sm3+ and Zr4+-dopant content and different doses of photocatalyst on the photodegradation of methylene blue (MB) were monitored under UV-light illumination. TiO2:0.5%Sm3+ and TiO2:1.0%Zr4+ nanofibers have shown the highest photocatalytic activity of 97% and 98% due to red shifting of the band gap towards visible light in the case of Sm and suppressed electron-hole recombination shown in recorded PL spectra in the case of Zr.