Photoluminescence properties of pure, Fe-doped and surfactant-assisted Fe-doped tin-oxide nanoparticles

A co-precipitation method with water as a distinctive solvent was used for the synthesis of pure, Fe-doped and surfactant-assisted Fe-doped SnO₂ nanoparticles (NPs). Furthermore, the NPs were characterized using X-ray diffraction (XRD), Fourier-transform infrared, scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDAX), high-resolution transmission electron microscopy (HRTEM), UV–visible, photoluminescence spectroscopy and spectrofluorometer. XRD patterns showed a tetragonal rutile structure of SnO₂ phase without additional peaks and a shift was noted for Fe-doped and surfactant-assisted Fe-doped samples. The crystallite sizes of Fe-doped and surfactant-assisted Fe-doped SnO₂ NPs were found to decrease from 10.39 to 6.347 nm. Spherical morphology with uniform size was observed in all samples from SEM and HRTEM images. The presence of Sn, O and Fe ions was confirmed by EDAX analysis. The band gap energy of NPs was measured to be 3.487, 3.741, 3.845, 3.783 and 3.552 eV for pure, Fe-doped, cetyltrimethylammonium bromide, sodium dodecyl sulphate and Triton (surfactants) assisted Fe-doped NPs, respectively. An increase in the band gap was observed due to addition of Fe and surfactants. The photocatalytic study confirms that pure SnO₂ NPs exhibit a significant photo-degradation of methylene blue dye under sun light. Moreover, the physical properties of SnO₂ were modified by Fe-doping and addition of surfactants in comparison with pure SnO₂ NPs.