Effect of Nb substitution on magnetic, ferroelectric and photocatalytic properties of Bi0.95Sm0.05Fe1-xNbxO3 (0 ≤ x ≤ 0.1) nanoparticles

The single phase Bi0.95Sm0.05Fe1-xNbxO3 (0 <= x <= 0.1) nanoparticles were synthesized by the sol-gel route, and the effect of Nb substitution on their magnetic, ferroelectric and photocatalytic properties were studied. X-ray diffractometry confirms a phase transformation from rhombohedral to orthorhombic with an increase in Nb substitution. The grain size decreases significantly, and the morphology of grains becomes homogeneous with the increase of Nb concentration. The maximum remnant magnetization (0.014 emu/g), coercivity (565 Oe) and polarization (0.592 mu C/cm(2)) are observed in Bi0.95Sm0.05Fe0.9Nb0.1O3. It has been observed that the energy band gap has been slightly reduced from 2.14 to 2.03 eV with Nb substitution, indicating an improvement of photocatalytic activity. The methylene blue degradation is used to represent the photocatalytic ability of co-Bi0.95Sm0.05Fe1-xNbxO3 nanoparticles. The highest degradation efficiency (similar to 74%) of methylene blue is obtained in Bi(0.95)Sm(0.05)Fe(0.93)Nb(0.0)7O(3), which is much higher than that of Bi0.95Sm0.05FeO3 (similar to 51%) and can be attributed to the optimum particle size and the smallest energy band gap.